Immunity,feed,and husbandry in fish health management of cultured Epinephelus fuscoguttatus with reference to Epinephelus coioides

Ctherine Cheng Yun Chieng,Hssn M.Dud,Ftimh M.Yusoff,Mh Adullh

aLaboratory of Marine Biotechnology,Institute of Bioscience,Universiti Putra Malaysia,Serdang 43400,Malaysia

bDepartment of Veterinary Clinical Studies,Faculty of Veterinary Medicine,Universiti Putra Malaysia,Serdang 43400,Malaysia

cDepartment of Pathology,Faculty of Medicine and Health Sciences,Universiti Putra Malaysia,Serdang 43400,Malaysia

1.Introduction

Groupers in the family Epinephelidae are formed by 16 genera encompassing 163 species(Craig,Sadovy,&Heemstra,2011)and are ray- finned,bony fishes distributed worldwide in the tropics and subtropics.They are of economic importance due to their high market value and consumer demand in the live reef fish trade.Global production of grouper has been increasing steadily over the years and the output in 2014(data include seabasses)was 139 kilotonnes valued at 654 million USD(FAO,2016).

Despite considerable difficulties in the initial cultivation of groupers involving seed,feed,and diseases,remarkable improvements have since been made in terms of brood stock management and breeding programs,larval rearing,production of hatcheryreared fingerlings,and successful culture to marketable size(Liao,Su,&Chang,2001;Mat Ali,Om,Idris,Mustafa,&Teoh,2006;Mustafa,Hajini,Senoo,&Kian,2015;Sugama et al.,2012).Nonetheless,health management continues to be a major concern in aquaculture as intensive farming and associated overcrowding stress have been linked to mass mortality events and huge economic loss(Ma,Xie,Weng,Zhou,&He,2012).

In this review, fish health management is discussed from three viewpoints:(1)understanding fish immunity through infection studies and vaccination trials,(2)enhancing fish growth and hardiness through the use of optimal feeds and immunostimulants,and(3)improving culture success through good husbandry practices and interspecific hybridization.Improvements in these aspects ultimately contribute to healthy fish with improved growth.Specific focus is given to Epinephelus fuscoguttatus(Forsskål,1775)(common name:brown-marbled grouper)which is a popular aquaculture candidate in the Indo-Pacific region in Southeast-Asian countriessuch asChina,Indonesia,Malaysia,and Thailand(Rimmer,Phillips,&Yamamoto,2007).

However,researches on E.fuscoguttatus is relatively scarce and therefore,a closely-related species,Epinephelus coioides(Hamilton,1822)(common name:orange-spotted grouper)is used as a reference.Both E.fuscoguttatus and E.coioides are placed in the same clade in phylogenetic studies(Ding et al.,2006;Guan et al.,2014;Ma,2014;Rahim,Esa,&Arshad,2016)and since E.coioides is the most extensively studied Epinephelus spp.it could serve as a“model”species.By comparing the two species,gaps in information regarding E.fuscoguttatus could be identified and stimulate more research into the deficient topics.

2.Understanding fish immune system:disease and immunological studies

Disease management is an inevitable part of aquaculture.Infectious diseases that frequently break out in farmed groupers are vibriosis caused by Vibrio spp.,streptococcosis caused by Streptococcus spp.,sleeping grouper disease caused by iridovirus,viral nervous necrosis caused by betanodavirus,and marine white spot disease caused by Cryptocaryon irritans.Antibiotics are widely administered in the face of these diseases,but their excessive use in aquaculture for both prophylactic and therapeutic purposes has led to persistent residues in the water,sediment,and fish products.This spurs the selective pressure for antibiotic-resistant microorganisms,not only in fish,but also consequently in terrestrial animals and humans(Cabello,2006).Thus,understanding immune response in fish has garnered increasing interest because it is critical in the combat against pathogens without the health risks posed by the use of antibiotics.This section will therefore focus on innate and adaptive defence mechanisms,vaccination methods for disease prevention,targets for therapeutic interventions,and biomarkers for monitoring the immune response.

2.1.Innate immune response against bacteria,virus,and parasites

Studies on bacterial infection in fish are concentrated on pattern recognition receptors(PRRs)that initiate downstream signalling leading to recognition of pathogen-associated molecular patterns(PAMPs)and an immune response against invading pathogens.A number of PRRs from E.coioides had been successfully cloned and characterized,including Toll-like receptor(TLR)1,TLR2(Wei et al.,2011b),and TLR22(Ding et al.,2012).Activation of these PRRs resulted in production of pro-in flammatory cytokines such as IL-1β and TNF-αthrough activation of MAPK signalling cascade via MyD88 adaptor.All of these molecules were upregulated in major lymphoid organs such as the spleen and head kidney of E.coioides upon infection with Vibrio alginolyticus(Ding et al.,2012;Wei et al.,2011b).In addition to extracellular PRRs,increased expression of intracellular PRRs such as NOD1 and NOD2 in the spleen(Hou et al.,2012)potentiated the in fl ammatory response mediated by IL-8 via RICK adaptor in E.coioides.Other antibacterial factors were also triggered,such as extracellular C-type lysozyme(Wei et al.,2012b),intracellular G-type lysozyme(Wei et al.,2014a),hepcidins(Qu,Chen,Peng,&Wang,2013;Zhou et al.,2011),complement C8 beta(Luo,Xie,Liu,&Wang,2015a),and voltage-dependent anion channel 1(Shi,Zhao,Hong,Chen,&Zhu,2014).

In addition to pro-inflammatory molecules, V. alginolyticusinfection in E. fuscoguttatus upregulated serum proteins such asapolipoprotein A-I, natural killer cell enhancement factor, and Gtypelysozyme (Low, Shamsudin, Chee,,&Aliyu-Paiko,2015b),the resistant fish overexpressed immune-activating moleculessuch asparvalbumin,alpha-2-macroglobulin,and nattectin.The susceptible fish,that had muscle lesions,overexpressed anti-in fl ammatory apolipoprotein E.Both resistant and susceptible fish expressed immunoglobulin light chain proteins,albeit with different peptide sequences.These studies highlight the diversity of protein expression in serum which may be useful as markers of disease resistance and susceptibility.

Whereas in E.coioides infected with Singapore grouper iridovirus(SGIV),numerous genes were found to be modulated in the spleen(Huang et al.,2011)and head kidney(Wu et al.,2012).The altered genes were cytokine and cytokine receptors,transcription factors,apoptotic factors,as well as those involved in intracellular signalling pathways(TLR,MAPK,chemokines,retinoicacidinducible gene 1,and p53),cytoskeleton,and metabolism.However,more experimental work is needed to examine the functional expression of individual genes to learn the mechanisms through which host protection is conferred.For instance,thioredoxin(Wei et al.,2012a)and TRP14(Wei,Ji,Guo,Yan,&Qin,2013b)were found to be antioxidants which could strengthen viability of host cells under SGIV infection and at the same time inhibit viral transcription.Similarly,IκBα orthologues(Gao et al.,2014)and p38β(Cai et al.,2011)protected E.coioides by suppressing SGIV replication,while p38βcould further restrain host cell apoptosis.

Viral nervous necrosis caused by nodavirus,which is an RNA virus,mayelicit different immune mechanisms in the fish than that caused by iridovirus,a DNA virus.One of the upregulated genes in the liver of E.coioides after nodavirus and polyI:C(an analogue of double-stranded RNA)infections was TLR3(Lin et al.,2013),which could triggera downstream signalling cascade involving TRIF,NF-κВ and IFN response promoters(Wei,Zhang,Zang,&Qin,2017),invitro interferon regulatory factor 3(IRF3)(Huanget al.,2015),and interferon-stimulated gene 15(ISG15)(Huang et al.,2013)resulting in an inflammatory response towards the viral stimulation.Type I interferon was also found to localize in the gut(Chen et al.,2014b),implying the involvement of mucosal immunity.However,expression of TLR3 was consistently low in fertilized egg until 10 days post-hatching,after which it gradually increased and only reached a significant level in 30-day old larvae(Lin et al.,2013).This observation may explain the particular vulnerability of grouper larvae towards viral diseases.

Unfortunately,viruses are capable of exploiting the host immune system to their bene fi t.For instance,upregulation of cathepsin B(Wei et al.,2014b)and LITAF(Cai et al.,2013)in the spleen of E.coioides after iridovirus infection accelerated both viral replication and virus-induced host cell apoptosis.Similarly,activation of transcription factor c-Jun(Wei,Huang,Huang,&Qin,2015)and Rab7(Fu et al.,2014)were shown to participate in viral transcription,transport and assembly of viral genes.In nodaviral infection,heat shock protein 90AB(HSP90AB)(Chen et al.,2010)and heat shock transcription factor 1(HSF1)(Wang,Chen,&Chen,2016)increased in E.coioides to overcome protein damage caused by in fl ammation but were instead appropriated by the virus to support its own polypeptide synthesis and cellular translocation.Nodavirus also reduced the levels of SPARC and prevented cells from spreading and adhering,subsequently inhibiting the usual cell repair after viral damage(Chen et al.,2011a).It has been postulated that inhibitors targeting molecules which work in favour of the virus may yield beneficial therapeutic outcomes.

Mucosal immunity was investigated in the skin transcriptome of E.coioides infested with Cryptocaryon irritans and revealed a multitude of upregulated genes that suggested an activated local immune response(Hu et al.,2017),corroborating and adding to the findings of previous studies(Li,Dan,Zhang,Luo,&Li,2011a;Li et al.,2011b,2012,2014;Mo et al.,2017;Ni et al.,2017).For example,innate factors involved in the acute phase response,natural resistance,and iron homeostasis such as serum amyloid A and hepcidin,cathepsins,together with transferrin and TFR1,respectively,were present in high levels.A number of PRRs(TLR1,TLR2,TLR5,TLR5S)and their respective downstream signalling molecules(MyD88,AP-1,IRF3,IRF7)and effectors(TNFα,IL1,IL6,IL8,IL12,IFNβ)were also upregulated.Increase in the levels of dendritic cell markers(CD83,CD209)suggested antigen presentation while markers associated with T cells(CD4,CD9,CD48)and B cells(CD22,CD81,Lyn)indicated lymphocyte activation.

While these infection studies enable the identification and characterization of molecules that are modulated in response to different pathogens,it is necessary to underscore the dichotomous nature of inflammation.Prolonged and unchecked inflammation may eventually be detrimental to the host.It is therefore noteworthy that fish are capable of maintaining immune homeostasis by generating antagonists to pro-inflammatory cytokines several days after inflammation was initiated.For instance,in E.coioides,PPAR gamma(Luo et al.,2015b)which inhibits the expression of pro-inflammatory IL-1,IL-6,and TNF was increased in response to a bacterial infection.In parasitic infections,sIL-1rI(Lu et al.,2013)dampened the level of IL-1 while TAK1(Li et al.,2015)impeded the TLR signalling process by reducing the level of NF-κВ.

In addition to the molecules studied in specific pathogen infections,there are other molecules which are generally expressed acrosstissues in E.coioides and upregulated regardless of the nature of the pathogen,such as serum amyloid A(Wei,Guo,Ji,&Qin,2013a),MHC IIb(Lu et al.,2012),CXCR4(Lin et al.,2012),CCL4(Hsu et al.,2013),LECT2(Wei et al.,2011a),and piscidins(Zhuang et al.,2017).An antimicrobial peptide,β-defensin,was also upregulated in both iridovirus and nodavirus infections,and subsequently activated type I interferon,IL-1β,and Mx gene which inhibitedviral infection and replication(Guo,Wei,Huang,Huang,&Qin,2012b).These constitutively-expressed molecules may be potential markers for monitoring general fish health.

Studies of disease and the immune response have generally been carried out in E.coioides and relatively few studies of the immune response in E.fuscoguttatus exist with the exception of a few studies with bacteria.We propose,taking into consideration its importance for aquaculture,that more attention is given to the grouper,E.fuscoguttatus.

2.2.Adaptive immune response and vaccination strategies

The key players in adaptive immunityare antibodies,B cells,and T cells.In addition to IgM which predominates in the serum,the existence of other teleost antibodies,IgT(Zhanget al.,2010)and IgZ(Danilova,Bussmann,Jekosch,&Steiner,2005;Hu,Xiang,&Shao,2010),has not been substantiated in Epinephelus spp.,and would be an avenue for further studies to determine immunoglobulin class diversity.Although these adaptive factors have not been directly studied in E.fuscoguttatus and E.coioides,successful vaccination trials which make use of the adaptive immune system can provide insight into the mechanisms of the adaptive response.

Inactivated whole pathogens are one of the earliest and mostwidely used vaccines. Given by injection to groupers, it took 2—4weeks to produce a significant amount of antigen-specific antibody,irrespective of whether the inoculum was bacterial (Huang et al.2014a), viral (Ou-yang et al., 2012; Pakingking, Bautista, de Jesus-Ayson,&Reyes,2010)or parasitic(Li et al.,2011a).By using an appropriate expression host,such as Vibrio anguillarum instead of Escherichia coli in a vaccine against nervous necrosis virus,the duration needed to achieve detectable specific antibody titre could be shortened from 16 to 7 days.This advantage might have resulted from the immunostimulant properties of using V.anguillarum.The same vaccine could also be bioencapsulated in Artemia,which made it convenient for oral administration to fish at an early age(Chen et al.,2011b).Subsequently,antibody levels could be maintained for up to 6 months after administering formalin-inactivated vaccines(Huang et al.,2014a;Pakingking et al.,2010).The time frame during which specific antibody levels could be detected provides insight into the timing of vaccination to prevent seasonal infections,for instance,streptococcosis for which outbreaks are more common in summer.

Other than antibody titre, immune-related genes are alsoupregulated after vaccination. The most commonly studied are proinflammatorycytokines IL-1β and TNF-α (Chen et al., 2011b; Dan,Zhang, Li, &:Li, 2013; Huang et al., 2014a; Ou-yang et al., 2012),MHCI in endogenous pathogens such as iridovirus (Ou-yang et al.,2012), MHC II in exogenous pathogens such as C. irritans (Dan et al.,2013), and Mx in viral infections (Chen et al., 2011b; Ou-yang et al.,2012). The expression of these marker genes can be used to evaluatethe efficacy of a vaccine, instead of the conventional challengeexperiments, which are time-consuming and require largenumbers of animals to be sacrificed. Parra, Reyes-Lopez, and Tort(2015) also suggested evaluation of the innate functions of B lymphocytes(phagocytosis, natural antibody production, cytokinesecretion, and possible antigen-presentation) to assess vaccinationsuccess. However, the paucity of characterization tools to identifyspecific cell types in both E. fuscoguttatus and E. coioides limits thestudy of cellular immunity and highlights the need for moredevelopment of this aspect.

In a separate study,E.fuscoguttatus fingerlings were given a single intraperitoneal injection of formalin-inactivated bet anodavirus vaccine which completely secured their survival when challenged with the virus while unvaccinated fish showed 70%mortality.The vaccinated fish were then subjected to a second virus challenge 5 months later and again,all fish survived.This virus rechallenge revealed that E.fuscoguttatus developed a memory response as the antibody titre sharply increased by 15-fold(Pakingking et al.,2010).Similarly in E.coioides,when fish were immunized with inactivated grouper iridovirus,the genes HECT,PLAUR,IgM,Mx-1,VLIG1,and TNF-αwhich were modulated during primary immunization were again detected after the booster(Wu et al.,2012).Anamnesis observed in these studies showed effective protection rendered by the vaccines,which could prevent vertical transmission of the virus to fish egg or larvae if broodstocks are regularly vaccinated and given booster doses.

E.fuscoguttatus and E.coioides are equally responsive to vaccination strategies,which typically guarantee their survival from subsequent pathogen challenge.However,pinpointing suitable pathogenic strains to be used to develop candidate vaccines in different fish species or within the same species which are geographically distant still remains a challenge.Other points that should be considered include dose(Dan et al.,2013),inactivating temperature,types of inactivating chemical(Ou-yang et al.,2012),the use of an adjuvant(Huang,Cai,Pang,Jian,&Wu,2017),the amount of time needed to reach a significantly high titre that provides protection,the efficacy of the vaccine when administered via different routes,and the ease of implementation in the farm.All these factors should be taken into account when testing or reporting the results of vaccine trials.

2.3.Other immune aspects and assisting body systems

Apart from the myriad of soluble factors produced in response to infections,groupers are also structurally adept at carrying out immune functions,as exempli fi ed by Firdaus-Nawi,Zamri-Saad,Nik-Haiha,Zuki,and Effendy(2013)in their investigation of the intestinal morphology in E.fuscoguttatus juveniles.The anterior intestine facilitated digestion and absorption of nutrients by having the most numerous and longest villi,the midgut served as a transition phase involved in both absorption and innate immunity,while the posterior gut had the thickest lamina propria which provided space to harbour a large number of lymphoid cells involved in adaptive immunity.White blood cells were observed in the gut as earlyas 30 days after hatching and became well established by 60 days,and indicated the maturation state of the immune system and the appropriate age for executing an immunological intervention.

Microbiota,or commensal microorganisms,are increasingly being recognized for their role in moulding fish immunity,specifically the mucosal immune system,as reviewed by Gomez,Sunyer,and Salinas(2013).Based on a study in E.coioides larvae,gut microbiota could be detected as early as 2 days post-hatching before any feed was given.Despite being fed different diets,all the larvae exhibited similar bacterial communities,implying a propensity to select for certain bacteria as micro flora.Thus,microbiota were deduced to be more closely correlated with rearing waters than feeds(Sun,Yang,Ling,&Ye,2015).To manipulate and enhance the function of microbiota,E.coioides were fed with probiotic Psychrobacter sp.SE6 for 60 days,resulting in the suppression of certain bacteria in the gut probably due to increased levels of TLR2,antibacterial epinecidin-1,and IgM(Sun,Xia,Yang,Wang,&Zou,2014).

Given the complexity of an organism,bodily processes leading to the elimination of pathogens should not be con fi ned to the immune system alone.For instance,changes observed in the spleen transcriptome of E.fuscoguttatus infected with V.parahaemolyticus identified involvement of metabolic pathways such as protein and sugar processing,drug and xenobiotic metabolism by cytochrome P450,and metabolism of steroid hormone and retinoic acid(Low,Mariana,Maha,Chee,&Fatimah,2015a).In viral infections,gene networks linked to energy and metabolism,protein synthesis,transcription,translation,degradation,and structure were altered by infection with SGIV in E.coioides(Wu et al.,2012).These auxiliary activities in the spleen and head kidney act as a resource and enhance the function of the immune system.

By evaluating research outcomes in recent years,trends and gaps in the field of immunology between E.fuscoguttatus and E.coioides could be determined.Table 1 provides a summary of the immune molecules already mentioned in different types of infections.As more molecules or cells are being identified,a more comprehensive picture of how fish mount an immune response towards pathogens can be obtained,and new therapeutic targets or disease management strategies can be proposed.

3.Enhancing growth and hardiness:feeds and immunostimulants

3.1.Feed substitutes and economical ingredients

In a commercial aquaculture setting,fast growth of fish is desired for rapid turnover and pro fit.The key element in this process is feed,since it is the main nutrient source.Feed ef fi cacy can be measured by the feed conversion ratio(FCR),which is the proportion of feed provided relative to the amount of weight gain.Groupers are carnivores and require a higher protein diet than other fish that are herbivores or omnivores.According to a review by De Silva and Turchini(2009),grouper culture employs the highest use of low-value or trash fish up to 80%with poor FCR.For example,cultured E.fuscoguttatus in Bali,Indonesia that was fed trash fish had FCR of 8.0—10.0 compared to 2.0—2.5 when commercial feed was given.Therefore,use of formulated feed with a better FCR is greatly advocated to replace the unsustainable practice of exploiting trash fish.

Grouper fingerlings digested proteins and lipids better than carbohydrates(Muhammadar et al.,2012).Optimal protein/lipid levels were determined to be 50/16%for E.fuscoguttatus(Shapawi,Ebi,Yong,&Ng,2014)and 48/10%for E.coioides(Luo et al.,2004,2005).A protein content study on common commercially available feeds given to grouper found that they complied with the recommended protein content(Muhammadar,Mazlan,Samat,Muchlisin,&Simon,2011).A carbohydrate-to-lipid ratio of 0.5 had also been identi fi ed as the optimal non-protein energy source for E.coioides(Wanget al.,2017a).Docosahexaenoic acid(DHA)and eicosapentaenoic acid(EPA)were both required in the diet of E.coioides juveniles in a ratio of 1:1 and 2:1 for enhanced growth and immunity(Chen,Chen,Wang,You,&Li,2017).

During the larval stage,brine shrimp Artemia is commonly given as live prey but alternative crustaceans such as mysids(Mesopodopsis orientalis),were nutritionally superior for E.fuscoguttatus,and contained higher levels of protein,lipid,and EPA.Mysids were also a rich source of DHA,a nutrient absent from Artemia(Eusebio,Coloso,&Gapasin,2010).For E.coioides larvae,Panagrellus redivivus,a nematode,had been proposed at the onset of exogenous feeding as it was easier to prepare and less expensive than Artemia(Reyes,Duray,Santiago,&Ricci,2011).

However,for juveniles and grow-out groupers,a continuous supply of high protein and lipid diets is very expensive because it relies on fish meal and fish oil of which there is a limited supply and it also depletes the fishery resources and causes environmental pollution and is not sustainable.Therefore,cheaper but equally nutritious ingredients should be incorporated into feeds to partially replace the conventional meals.Replacement diets have been developed that were mostly well-tolerated in both E.fuscoguttatus and E.coioides and did not affect their growth and survival.

Among the alternatives tested in E.fuscoguttatus were poultry by-product and fish meal mixed in equal proportions(Gunben,Senoo,Yong,&Shapawi,2014)and fish meal supplemented with 10%beer yeast,10%soybean(Chen,Zhou,&Gu,2014a)or 10—15%milk fish offal hydrolysate(Mamauag&Ragaza,2017).In E.coioides,compounds that have been evaluated were 40%processed meat solubles(Millamena&Golez,2001),20%animal by-product(Millamena,2002),and 30%Bacillus subtilis E20-fermented soybean meal(Shiu et al.,2015).Fish oils could be substituted by plant oils such as soybean,corn,sun flower,peanut(Lin,Liu,He,Zheng,&Tian,2007;Niu et al.,2007)or microalgae(Lee,Zhuo,&Lin,2017a).The nutritional content of feeds was retained and this was reflected in the nutrient content of the fish fillet.For example, fish feed supplemented with microalgal oil which had a higher DHA content compared to the control feed resulted in a higher level of DHA in the fish fatty acid pro file(Lee et al.,2017a).

Table 2 summarizes the proposed feed and ingredient substitutes in both the species.Fish meal still could not be totally replaced by alternative sources because its exclusion was detrimental to the fish.For instance,E.coioides showed a decrease in weight gain rate due to reduced feed intake and efficiency when put on 50%or 100%soybean meal.Histological examination of the intestines showed diminishing villus height and lesions with in filtration of leukocytes.The mRNA expression of proinflammatory IL-1βand IL-16 increased while anti-in flammatory IL-10 decreased(Wang,Wang,Zhang,&Song,2017b).This study showed that optimal levels of meal replacement should be determined empirically to yield a beneficial result.

3.2.Immunostimulants as boosters and growth-promoters

The practice in intensive farming to minimize cost and increase production often leads to overcrowding in cages and ponds.This stresses the fish and weakens their immunity,predisposing them to diseases.In recent years,immunostimulants have beenincorporated into feed to enhance fish immunity and as an added benefit,frequently improve the growth of the fish as well.The field of oral immunostimulants is appealing as it strengthens the fishes own defence mechanisms;hence,it seems likely that these compounds could be applied to other species as well.

Table 1 Molecules involved in the immune response against different pathogens.

A popular candidate immunostimulant is seaweed extract.In E.fuscoguttatus,dietary administration of 1g/kg or 2 g/kg of sodium alginate to 9g fish(Chiu,Tsai,Hsu,Liu,&Cheng,2008),10g/kg of sodium alginate to fish smaller than 1 g,and 5g/kg of kappacarrageenan(Cheng,Chen,&Chen,2008)enhanced survival and resistance against pathogens such as V.alginolyticus,Streptococcus sp.,and iridovirus.The different doses of sodium alginate could be due to the different age/size of the grouper studied.In E.coioides,sodium alginate worked best to improve growth by increasing weight gain and feeding efficiency at 1g/kg while feeding at 2g/kg increased survival when challenged with Streptococcus sp.and iridovirus(Yeh,Chang,Chang,Liu,&Cheng,2008).Cheng,Tu,Chen,Nan,and Chen(2007)used a much lower dose for intraperitoneal injection(20mg/kg sodium alginate or 30 mg/kg iota-carrageenan)to enhance the survival of E.coioides against V.alginolyticus infection.

Other prospective immunostimulants with promising results in terms of increased survival when challenged with pathogens were onion and ginger in E.fuscoguttatus(Apines-Amar,Amar,&FaisanJr.,2013;Apines-Amar,Amar,Faisan Jr.,Pakingking Jr.,&Satoh,2012)and in E.coioides;garlic(Guo et al.,2012a),lactoferrin(Yokoyama et al.,2006),probiotic Saccharomyces cerevisiae P13(Chiu,Cheng,Gua,Guu,&Cheng,2010),recombinant epinecidin-1(Pan et al.,2012),recombinant Reishi immunomodulatory protein rLZ-8(Kuan et al.,2012),mushroom beta-glucan mixture(Chang,Huang,Chen,&Chen,2013),laminarin(Yin et al.,2014),fatty acid binding protein(FABP10)(Luo,Cai,Liu,&Wang,2014),and katuk(Samad,Santoso,Lee,&Nan,2014).

Table 2 Suggested feed alternatives for Epinephelus fuscoguttatus and Epinephelus coioides at different developmental stages compared to the conventional feeds.

Some immunostimulants have the added benefit of improving fish growth,such as sodium alginate(Yeh et al.,2008),laminarin(Yin et al.,2014),katuk(Samad et al.,2014),garlic(Guo et al.,2012a),onion(Apines-Amar,Amar,Faisan,Pakingking,&Satoh,2012,2013),ginger(Apines-Amar et al.,2013),probiotic Saccharomyces cerevisiae(Chiu et al.,2010),and epinecidin-1(Pan et al.,2012);probably by promoting the appetite and increasing feed efficiency.They also exerted their effects in strengthening the immune system by ameliorating stress(Apines-Amar et al.,2013;Lee,Lin,Chen,&Cheng,2017b;Yokoyama et al.,2006)and by boosting innate immune parameters such as the respiratory burst,superoxide dismutase activity,phagocytic activity,lysozyme,alternative complement pathway activity(Chang et al.,2013;Cheng et al.,2007,2008;Chiu et al.,2008;Chiu et al.,2010;Lee et al.,2017b;Samad et al.,2014;Yeh et al.,2008),and upregulation of immune-related genes such as IL-1β(Kuan et al.,2012;Yin et al.,2014),IL-8,TLR2(Yin et al.,2014),TNF-α(Kuan et al.,2012),and Mx(Cheng,Tsai,&Chang,2012).

It is noteworthy that when formulating feeds and immunostimulants,more is not always better(Chang et al.,2013;Chen et al.,2014a;Cheng et al.,2008;Gunben et al.,2014;Kuan et al.,2012;Millamena&Golez,2001;Millamena,2002;Samad et al.,2014;Yeh et al.,2008).To ensure cost-efficiency,convenience of handling,and to achieve the desired purpose(whether for growth or immune enhancement),the dosage,timing,treatment duration,age/size of fish,and route of administration have to be considered.

4.Improving culture success:husbandry and hybridization

4.1.Good husbandry practices for optimal growth

Environmental factors and good husbandry practices that are ideal for fish growth are equally important to guarantee fish health in addition to efforts in understanding and boosting the immunological response of fish.These aspects include salinity,temperature,aeration,lighting conditions,optimal time for first feeding of larvae,and avoiding cannibalism in juveniles.A comparison of these husbandry parameters between E.fuscoguttatus and E.coioides is summarized in Table 3.

In E.fuscoguttatus,a gradual change in salinity and temperature was better tolerated than a drastic change,as is evident by the higher survival rate.The range of temperatures which could be endured by E.fuscoguttatus depended on the temperature under which the fish were first acclimatized.For instance, fish that were acclimated at a high temperature could adjust to temperature changes in the high range,and vice versa(Cheng,Chen,&Chen,2013).In terms of different salinity regimes,the absolute growth rate of fish(in terms of length)and the specific growth rate(in terms of weight)were highest while the mortality rate was lowest in fish reared at 32 PSU compared to 22 and 28 PSU(Muhammadar et al.,2014).

The capacity to respond to changes in salinity and temperature differed across developmental stages in E.coioides(Caberoy&Quinitio,2000).In 20-day pre-metamorphic larvae,abrupt transfer to salinities ranging from 8 to 32 ppt was well tolerated at 25°C.At a higher temperature of 30°C,the larvae could only withstand changes between 8 and 18 ppt,with 65%mortality occurring in larvae exposed to 32 ppt.However,after 60 days,they were able to grow in a salinity range of 8—40 ppt at both 25°C and 30°C.This ability to adapt was achieved through maturity in terms of number,size,and Na+,K+-ATPase activity of branchial chloride cells,which are the main osmoregulatory cells in fish.It also reflected the natural estuarine environment of E.coioides where salinity often fluctuates,before the juveniles migrate to deeper and more stable waters.Nonetheless,the optimal salinity in culture was determined to be between 16 and 24ppt(Toledo,Caberoy,Quinitio,Choresca,&Nakagawa,2002).

Sinking syndrome-related death(SSRD)had been observed in E.fuscoguttatus larvae(Ching et al.,2016a)and is characterized by reduced activity and the gradual sinking of larvae to the bottom of the tank and death.This usually happens at night when there is cessation of activity and larvae depended largely on the water current to stay a fl oat.Therefore,aeration which creates a continuous flow field is essential to curb SSRD.During daytime when larvae actively swim and feed,an aeration rate of 0.6mL/min/L is sufficient,and an increase to 1.8 mL/min/L at night benefitted survival and growth of the larvae.For E.coioides larvae,gentle aeration of 0.62—1.25 mL/min/L has been recommended(Toledo et al.,2002).

Apart from temperature,salinity,and aeration,lighting conditions were also a crucial factor which could affect the egg-hatching rates in E.fuscoguttatus(Seth et al.,2014).Fluorescent lamps,which represent white light,are common in hatcheries.When compared to lights of different wavelengths at the green,blue,red,and yellow spectrum,white light was the least effective for egg-hatching while green light was most effective.Various light intensities have been tested but there was no significant effect on the hatching rate.Nonetheless,green light of 528 nm at the intensity of 2.7μmol/m2/s was recommended as the optimum lighting condition for eggincubation of E.fuscoguttatus.

Table 3 Comparison of good husbandry practices to ensure optimal growth of Epinephelus fuscoguttatus and Epinephelus coioides in culture.

After hatching,light intensity has to be adjusted with age.If it is too low the larvae may not feed and if it is too high it may be lethal.Retinal cone and rod cells were developed 20 days after hatching in E.fuscoguttatus(Lim&Mukai,2014)and the retinomotor response was complete by 42 days,with the most favourable light intensity between 10 and 100 lx(Mukai,Lim,&Saad,2012b).This was in contrast with E.coioides larvae where the light intensity range was between 500 and 700 lx(Toledo et al.,2002).The lower light intensity requirement for E.fuscoguttatus may be due to the presence of free neuromasts behind the eyes which aid vision under dim light (Mukai & Seng Lim,2016).Feed ingestion rates inE.fuscoguttatus larvae in a conducive light environment(＞10 lx)was 80%higher than the feed intake in the dark(＜1 lx)(Mukai,Lim,Lu,Abdul Rashid,&Saad,2012a).Optimal light intensity for feeding was between 600 and 1150 lx for E.coioides juveniles,which was also most favourable for activities of digestive enzymes such as protease,lipase,and amylase,thereby benefitting nutrient assimilation and growth(Wang,Cheng,Liu,&Long,2015).

The time of first feeding is another critical factor to consider in the survival of grouper larvae.This timepoint is crucial to prevent death from starvation because in the case of E.fuscoguttatus,they have a short nutrition transitional period from endogenous yolk sac absorption to exogenous feed intake.The optimal first feeding time was determined to be 53 h after hatching and coincided with mouth opening(Ching,Nakagawa,Kato,Murata,&Miyashita,2012).Larvae which were fed at this period showed healthy gut epithelium development and proportionate growth in body length.Delaying first feeding caused degradation of the gut tissue which in turn stunted growth(Ching,Nakagawa,Kato,Miyashita,&Senoo,2016b).There was an irreversible “point of no return”determined at 67h after hatching which negatively impacted the ability of the larvae to take up feed(Ching et al.,2012).

Feeding is usually carried out by hand or using an automatic feeder that releases a certain amount of pellets at a preset time schedule.On-demand feeders with a mechanical switch activated by the weight of the larvae are also utilized,but this system is not suitable for developing fish,which are not heavy enough to trigger the feeder.Therefore,Mukai,Tan,Rosli,and Liau(2016)tested the efficacy of an infrared light sensor on-demand feeder that was installed 2 cm below the water surface,with a pellet-like knob which was a further 1 cm underneath the sensor to act as the target to cue hungry fish.Once triggered,approximately 15 pellets were released one after the other every 3s to prevent wastage.When compared to an automatic feeder, fish in the infrared sensor feeder group showed an increasing trend in body length and improved FCR,making this apparatus useful for the culture of E.fuscoguttatus juveniles.

Lastly,cannibalism is a common phenomenon in grouper culture during the late larval and juvenile stages.The larger grouper in the tank swallows its prey fully head first and kills it;a behaviour known as Type II cannibalism(Hseu,2002)which is exhibited by both E.coioides and E.fuscoguttatus.However,it has been observed in E.fuscoguttatus that the predator is often unable to swallow its prey whole and this resulted in co-death.This was because at the same mouth width,E.fuscoguttatus had a larger body depth compared to E.coioides,making it bulkier and more difficult to swallow(Hseu,Huang,&Chu,2007).The team further demonstrated most of the cannibalism happened when the total length of the predator was 150%of the prey's in E.fuscoguttatus,compared to 130%in E.coioides(Hseu,Chang,&Ting,2003a).Supplementation of 0.5%tryptophan in the diet could reduce the incidence of cannibalism by increasing serotonin levels and subsequently suppress aggression,but at the expense of fish growth(Hseu et al.,2003b).Therefore,even though it is stressful to the fish,grading is still the most effective solution for cannibalism by separating the fish before size disparity is highly manifested.

Taken together,difference in the culture requirements listed above between E.fuscoguttatus and E.coioides reveals the heterogeneous nature of these two otherwise closely-related species.Research should be individually carried out to determine the most suitable conditions in which to grow each grouper species.

4.2.Interspecific hybridization as a method of stock improvement

Interspecific hybridization is the mating of fish that are genetically different and may involve crosses within or between species and the intention is to produce offspring that are superior to both parents(Bartley,Rana,&Immink,2000).However,systematic documentation of this technique and the resulting production scale of successful hybrids are under-reported.In grouper culture,hybridization is viewed as one of the means to overcome scarce seed supply from hatcheries,lack of appropriate broodstock,and inconsistent survival of larvae.

Successful attempts at hybridization validated by hybrid vigour have been performed in E.fuscoguttatus and E.coioides with other Epinephelus spp.For instance,hybrids of female E.fuscoguttatus and male E.polyphekadion(camouflage grouper)(James,Al-Thobaiti,Rasem,&Carlos,1999)showed faster growth and a better food conversion ratio.Offspring of female E.fuscoguttatus and male E.lanceolatus(giant grouper)(Ch'ng&Senoo,2008)could withstand low water pH and salinity,(Liang,Huang,Wu,Wang,&Zhong,2013;Mustafa,Senoo,&Luin,2013),showed accelerated growth(De,Ghaffar,&Das,2014),were receptive to less costly soybean-based feeds(Firdaus,Lim,Kawamura,&Shapawi,2016),and had a high possibility of being fertile(Luin,Fui,&Senoo,2013).Crossbreeding between E.coioidesand maleE.lanceolatus(Kiriyakit,Gallardo,&Bart,2011)produced hybrids which were euryhaline,growing well in a salinity ranging from 10 to 30 ppt(Sutthinon,Thongprajukaew,Saekhow,&Ketmanee,2015).

On the other hand,hybridization is a hit and miss project.This was apparent when two phenotypes were observed among the hybrids of E.fuscoguttatus and E.polyphekadion.The first phenotype closely resembled E.polyphekadion and was smaller in size than the second phenotype which was similar to E.fuscoguttatus,although both achieved faster growth than their parents(James et al.,1999).Crossbreeding between E.coioides and E.lanceolatus produced hybrids which could be diploid or triploid.The triploid hybrid showed retarded gonad development but grew to be the largest among the population,whereas the size of the diploid hybrid was comparable to E.lanceolatus(Huang et al.,2014b).Therefore,it would be advantageous to understand the underlying mechanisms that contribute to hybrid vigour.For instance,hybrids with superior growth showed upregulated genes associated with glycolysis,calcium signalling,and troponins,which are important for muscle development(Sun et al.,2016).These identified genes could then be applied in marker-assisted selective breeding to increase the chances of obtaining hybrids with desired traits.

As both E.fuscoguttatus and E.coioides are protogynous hermaphrodites,it is difficult to obtain mature male specimens,and when available,to synchronize the male spermiation and female ovulation for mating.One way to overcome this is to cryopreserve the sperm,and this method has proven to be successful in the hybridization of E.coioides and E.lanceolatus(Kiriyakit et al.,2011).Recommended cryopreservatives for sperm were 10%DMSO or 10%propylene glycol at a dilution ratio of 1:3,frozen at a cooling rate of 20°C/min.This storage condition resulted in more than 90%viable sperm after thawing and more than 85%successful fertilization and hatching rates.The development of hybrid embryos and growth of subsequent larvae were also normal(Liu et al.,2016).Hence,sperm cryopreservation is an effective step towards improving grouper seed production and availability.

Looking upon the success of these hybrids,it is undeniable that hybridization is one method that gives almost immediate and tangible rewards.Nonetheless,there are some notable measures to be taken to ensure that these gains are long-lasting.Besides testing the hybrids for viability(ability to survive)and fertility(ability to reproduce),proper broodstock management is essential in order to identify the correct parental lines and appropriate sex to be used to produce the desired hybrid.For example,a panel of molecular markers has been developed that was able to distinguish between the sire(E.lanceolatus),dam(E.coioides),and hybrid,and further distinguished these three individuals from closely-related species(E.corallicola and E.fuscoguttatus)(Lim,Senoo,Siddiquee,&Rodrigues,2014).

5.Conclusion

This review focuses on advances in scientific research on a popular aquaculture species of the grouper,E.fuscoguttatus and compared it with the long-studied E.coioides.While a vast array of studies has been conducted in E.coioides,literature on E.fuscoguttatus is still deficient and more extensive investigations are required.Nonetheless,existing reports discussed in this review have shed light on the importance of studying fish biology in order to guide health management efforts in aquaculture.Useful information can be derived from these studies whichcan then be used to improve culture conditions and cultivate more robust fish.It is imperative to engage in species-specific studies because generalizations or conjectures across different species are no longer appropriate,as demonstrated by these two closely-related groupers that have different biology and needs.

Conflicts of interest

None.

Acknowledgements

Our research was supported by Malaysian Ministry of Education(MOE)Higher Institution Centre of Excellence(HICoE)Grant No.6369100 and Malaysian Ministry of Science,Technology and Innovation(MOSTI)EScience Fund No.5450576.

Apines-Amar,M.J.S.,Amar,E.C.,&Faisan,J.P.,Jr.(2013).Growth,plasma cortisol,liver and kidney histology,and resistance to vibriosis in brown-marbled grouper,Epinephelus fuscoguttatus fed onion and ginger.AACL Bio flux,6(6),530—538.

Apines-Amar,M.J.S.,Amar,E.C.,Faisan,J.P.,Jr.,Pakingking,R.V.,Jr.,&Satoh,S.(2012).Dietary onion and ginger enhance growth,hemato-immunological responses,and disease resistance in brown-marbled grouper,Epinephelus fuscoguttatus.AACL Bio flux,5(4),231—239.

Bartley,D.M.,Rana,K.,&Immink,A.J.(2000).The use of inter-specific hybrids in aquaculture and fisheries.Reviews in Fish Biology and Fisheries,10(3),325—337.https://doi.org/10.1023/a:1016691725361.

Cabello,F.C.(2006).Heavy use of prophylactic antibiotics in aquaculture:A growing problem for human and animal health and for the environment.Environmental Microbiology,8(7),1137—1144.https://doi.org/10.1111/j.1462-2920.2006.01054.x.

Caberoy,N.B.,&Quinitio,G.F.(2000).Changes in Na+,K+-ATPase activity and gill chloride cell morphology in the grouper Epinephelus coioides larvae and juveniles in response to salinity and temperature.Fish Physiology and Biochemistry,23(1),83—94.https://doi.org/10.1023/A:1007827331137.

Cai,J.,Huang,Y.H.,Wei,S.N.,Huang,X.H.,Ye,F.Z.,Fu,J.,et al.(2011).Characterization of p38 MAPKs from orange-spotted grouper,Epinephelus coioides involved in SGIV infection.Fish&Shell fish Immunology,31(6),1129—1136.https://doi.org/10.1016/j.fsi.2011.10.004.

Cai,J.,Huang,Y.H.,Wei,S.N.,Ouyang,Z.L.,Huang,X.H.,&Qin,Q.W.(2013).Characterization of LPS-induced TNFαfactor(LITAF)from orange-spotted grouper,Epinephelus coioides.Fish&Shell fish Immunology,35(6),1858—1866.https://doi.org/10.1016/j.fsi.2013.09.023.

Ch'ng,C.,&Senoo,S.(2008).Egg and larval development of a new hybrid grouper,tiger grouper Epinephelus fuscoguttatus x giant grouper E.lanceolatus.Aquatic Sciences,56(4),505—512.

Chang,C.S.,Huang,S.L.,Chen,S.,&Chen,S.N.(2013).Innate immune responses and efficacy of using mushroom beta-glucan mixture(MBG)on orange-spotted grouper,Epinephelus coioides,aquaculture.Fish&Shell fish Immunology,35(1),115—125.https://doi.org/10.1016/j.fsi.2013.04.004.

Chen,C.,Chen,J.,Wang,S.,You,C.,&Li,Y.(2017).Effects of different dietary ratios of linolenic to linoleic acids or docosahexaenoic to eicosapentaenoic acids on the growth and immune indices in grouper,Epinephelus coioides.Aquaculture,473(Supplement C),153—160.https://doi.org/10.1016/j.aquaculture.2017.02.010.

Cheng,A.C.,Chen,Y.Y.,&Chen,J.C.(2008).Dietary administration of sodium alginate and kappa-carrageenan enhances the innate immune response of brown-marbled grouper Epinephelus fuscoguttatus and its resistance against Vibrio alginolyticus.Veterinary Immunology and Immunopathology,121(3—4),206—215.https://doi.org/10.1016/j.vetimm.2007.09.011.

Cheng,S.Y.,Chen,C.S.,&Chen,J.C.(2013).Salinity and temperature tolerance of brown-marbled grouper Epinephelusfuscoguttatus.Fish Physiology and Biochemistry,39(2),277—286.https://doi.org/10.1007/s10695-012-9698-x.

Cheng,W.,Tsai,R.T.,&Chang,C.C.(2012).Dietary sodium alginate administration enhances Mx gene expression of the tiger grouper,Epinephelus fuscoguttatus receiving poly I:C.Aquaculture,324—325(0),201—208.https://doi.org/10.1016/j.aquaculture.2011.10.032.

Cheng,A.C.,Tu,C.W.,Chen,Y.Y.,Nan,F.H.,&Chen,J.C.(2007).The immunostimulatory effects of sodium alginate and iota-carrageenan on orange-spotted grouper Epinephelus coioides and its resistance against Vibrio alginolyticus.Fish&Shell fish Immunology,22(3),197—205.https://doi.org/10.1016/j.fsi.2006.04.009.

Chen,Y.M.,Kuo,C.E.,Chen,G.R.,Kao,Y.T.,Zou,J.,Secombes,C.J.,et al.(2014b).Functional analysis of an orange-spotted grouper(Epinephelus coioides)interferon gene and characterisation of its expression in response to nodavirus infection.Developmental&Comparative Immunology,46(2),117—128.https://doi.org/10.1016/j.dci.2014.04.004.

Chen,Y.M.,Kuo,C.E.,Huang,Y.L.,Shie,P.S.,Liao,J.J.,Yang,Y.C.,et al.(2011a).Molecular cloning and functional analysis of an orange-spotted grouper(Epinephelus coioides)secreted protein acidic and rich in cysteine(SPARC)and characterization of its expression response to nodavirus.Fish&Shell fish Immunology,31(2),232—242.https://doi.org/10.1016/j.fsi.2011.05.008.

Chen,Y.-M.,Kuo,C.-E.,Wang,T.-Y.,Shie,P.-S.,Wang,W.-C.,Huang,S.-L.,et al.(2010).Cloning of an orange-spotted grouper Epinephelus coioides heat shock protein 90AB(HSP90AB)and characterization of its expression in response to nodavirus.Fish&Shell fish Immunology,28(5),895—904.https://doi.org/10.1016/j.fsi.2010.02.004.

Chen,Y.M.,Shih,C.H.,Liu,H.C.,Wu,C.L.,Lin,C.C.,Wang,H.C.,et al.(2011b).An oral nervous necrosis virus vaccine using Vibrio anguillarum as an expression host provides early protection.Aquaculture,321(1—2),26—33.https://doi.org/10.1016/j.aquaculture.2011.08.035.

Chen,G.,Zhou,H.,&Gu,B.(2014a).Carbon stable isotope evidence for the contribution of supplemental diets to the growth of brown-marbled grouper(Epinephelus fuscoguttatus,Forsskål 1775).Journal of Applied Animal Research,42(1),44—46.

Ching,F.F.,Miura,A.,Nakagawa,Y.,Kato,K.,Sakamoto,W.,Takii,K.,et al.(2016a).Aeration rate adjustment at night to prevent sinking syndrome-related death in the Tiger grouper Epinephelus fuscoguttatus(Perciformes:Serranidae)larvae.Aquaculture Research,47(1),165—175.https://doi.org/10.1111/are.12479.

Ching,F.F.,Nakagawa,Y.,Kato,K.,Miyashita,S.,&Senoo,S.(2016b).Effects of delayed fi rst feeding on nutritional condition of tiger grouper,Epinephelus fuscoguttatus(Forsskål,1775)larvae.Aquaculture Research,3(Supplement C),225—228.https://doi.org/10.1016/j.aqrep.2016.04.001.

Ching,F.F.,Nakagawa,Y.,Kato,K.,Murata,O.,&Miyashita,S.(2012).Effects of delayed fi rst feeding on the survival and growth of tiger grouper,Epinephelus fuscoguttatus(Forsskål,1775),larvae.Aquaculture Research,43(2),303—310.https://doi.org/10.1111/j.1365-2109.2011.02839.x.

Chiu,C.H.,Cheng,C.H.,Gua,W.R.,Guu,Y.K.,&Cheng,W.(2010).Dietary administration of the probiotic,Saccharomyces cerevisiae P13,enhanced the growth,innate immune responses,and disease resistance of the grouper,Epinephelus coioides.Fish&Shell fish Immunology,29(6),1053—1059.https://doi.org/10.1016/j.fsi.2010.08.019.

Chiu,S.T.,Tsai,R.T.,Hsu,J.P.,Liu,C.H.,&Cheng,W.(2008).Dietary sodium alginate administration to enhance the non-speci fic immune responses,and disease resistance of the juvenile grouper Epinephelus fuscoguttatus.Aquaculture,277(1—2),66—72.https://doi.org/10.1016/j.aquaculture.2008.01.032.

Craig,M.T.,Sadovy,Y.J.d.M.,&Heemstra,P.C.(2011).Groupers of the world:A field and market guide.Grahamstown,South Africa:National Inquiry Services Centre Pty Ltd.

Danilova,N.,Bussmann,J.,Jekosch,K.,&Steiner,L.A.(2005).The immunoglobulin heavy-chain locus in zebra fish:Identification and expression of a previously unknown isotype,immunoglobulin z.Nature Immunology,6(3),295—302.https://doi.org/10.1038/ni1166.

Dan,X.M.,Zhang,T.W.,Li,Y.W.,&Li,A.X.(2013).Immune responses and immunerelated gene expression pro file in orange-spotted grouper after immunization with Cryptocaryon irritans vaccine.Fish&Shell fish Immunology,34(3),885—891.https://doi.org/10.1016/j.fsi.2012.12.011.

De Silva,S.S.,&Turchini,G.M.(2009).Use of wild fish and other aquatic organisms as feed in aquaculture—a review of practices and implications in the Asia-Pacific.In M.R.Hasan,&M.Halwart(Eds.),Fish as feed inputs for aquaculture:Practices,sustainability and implications(pp.63—127).Rome:FAO.FAO Fisheries and Aquaculture Technical Paper.No.518.

De,M.,Ghaffar,M.A.,&Das,S.K.(2014).Temperature effect on gastric emptying time of hybrid grouper(Epinephelus spp.).AIP Conference Proceedings,1614(616),1—4.https://doi.org/10.1063/1.4895273.

Ding,X.,Lu,D.Q.,Hou,Q.H.,Li,S.S.,Liu,X.C.,Zhang,Y.,et al.(2012).Orangespotted grouper(Epinephelus coioides)toll-like receptor 22:Molecular characterization,expression pattern and pertinent signaling pathways.Fish&Shell fish Immunology,33(3),494—503.https://doi.org/10.1016/j.fsi.2012.05.034.

Ding,S.,Zhuang,X.,Guo,F.,Wang,J.,Su,Y.,Zhang,Q.,et al.(2006).Molecular phylogenetic relationships of China Seas groupers based on cytochrome b gene fragment sequences.Science in China-Series C:Life Sciences,49(3),235—242.

Eusebio,P.S.,Coloso,R.M.,&Gapasin,R.S.J.(2010).Nutritional evaluation of mysids Mesopodopsis orientalis(Crustacea:Mysida)as live food for grouper Epinephelus fuscoguttatus larvae.Aquaculture,306(1—4),289—294.

FAO.(2016).Fishery and aquaculture statistics.Global aquaculture production 1950-2014(Fishstat J).In FAO fisheries and aquaculture department.http://www.fao.org/fishery/statistics/software/fishstatj/en].Rome Updated 2016.

Firdaus-Nawi,M.,Zamri-Saad,M.,Nik-Haiha,N.Y.,Zuki,M.A.,&Effendy,A.W.(2013).Histological assessments of intestinal immuno-morphology of tiger grouper juvenile,Epinephelus fuscoguttatus.SpringerPlus,2,611.https://doi.org/10.1186/2193-1801-2-611.

Firdaus,R.F.,Lim,L.S.,Kawamura,G.,&Shapawi,R.(2016).Assessment on the acceptability of hybrid grouper,Epinephelus fuscoguttatus x Epinephelus lanceolatus to soybean meal-based diets.AACL Bio flux,9(2).

Fu,J.,Huang,Y.H.,Cai,J.,Wei,S.N.,Ouyang,Z.L.,Ye,F.Z.,et al.(2014).Identification and characterization of Rab7 from orange-spotted grouper,Epinephelus coioides.Fish&Shell fish Immunology,36(1),19—26.https://doi.org/10.1016/j.fsi.2013.10.002.

Gao,R.,Huang,Y.H.,Huang,X.H.,Guan,L.Y.,Wei,S.N.,Zhou,Y.C.,et al.(2014).Molecular cloning and characterization of two types of IκBα orthologues in orange-spotted grouper,Epinephelus coioides.Fish&Shell fish Immunology,38(1),101—110.https://doi.org/10.1016/j.fsi.2014.02.019.

Gomez,D.,Sunyer,J.O.,&Salinas,I.(2013).The mucosal immune system of fish:The evolution of tolerating commensals while fighting pathogens.Fish&Shell fish Immunology, 35(6), 1729—1739. https://doi.org/10.1016/j.fsi.2013.09.032.

Guan,S.,Liu,H.,Zheng,Y.,Yu,D.,Nie,A.,&Liu,M.(2014).Inference of phylogenetics and evolution of Epinephelus septemfasciatus and 48 other species of Epinephelus genus using mitochondrial CO1 fragment sequences.Pakistan Journal of Zoology,46(1),67—74.

Gunben,E.M.,Senoo,S.,Yong,A.,&Shapawi,R.(2014).High potential of poultry byproduct meal as a main protein source in the formulated feeds for a commonly cultured grouper in Malaysia(Epinephelus fuscoguttatus).Sains Malaysiana,43(3),399—405.

Guo,J.J.,Kuo,C.M.,Chuang,Y.C.,Hong,J.W.,Chou,R.L.,&Chen,T.I.(2012a).The effects of garlic-supplemented diets on antibacterial activity against Streptococcus iniae and on growth in orange-spotted grouper,Epinephelus coioides.Aquaculture,364—365(0),33—38.https://doi.org/10.1016/j.aquaculture.2012.07.023.

Guo,M.L.,Wei,J.G.,Huang,X.H.,Huang,Y.H.,&Qin,Q.W.(2012b).Antiviral effects ofβ-defensin derived from orange-spotted grouper(Epinephelus coioides).Fish&Shell fish Immunology,32(5),828—838.https://doi.org/10.1016/j.fsi.2012.02.005.

Hou,Q.H.,Yi,S.B.,Ding,X.,Zhang,H.X.,Sun,Y.,Zhang,Y.,et al.(2012).Differential expression analysis of nuclear oligomerization domain proteins NOD1 and NOD2 in orange-spotted grouper(Epinephelus coioides).Fish&Shell fish Immunology,33(5),1102—1111.https://doi.org/10.1016/j.fsi.2012.08.015.

Hseu,J.R.(2002).Effects of size difference and stocking density on cannibalism rate of juvenile grouper Epinephelus coioides.Fisheries Science,68(6),1384—1386.https://doi.org/10.1046/j.1444-2906.2002.00578.x.

Hseu,J.R.,Chang,H.F.,&Ting,Y.Y.(2003a).Morphometric prediction of cannibalism in larviculture of orange-spotted grouper,Epinephelus coioides.Aquaculture,218(1—4),203—207.https://doi.org/10.1016/S0044-8486(02)00315-0.

Hseu,J.R.,Huang,W.B.,&Chu,Y.T.(2007).What causes cannibalization-associated suffocation in cultured brown-marbled grouper,Epinephelus fuscoguttatus(Forsskål,1775)?Aquaculture Research,38(10),1056—1060.https://doi.org/10.1111/j.1365-2109.2007.01762.x.

Hseu,J.R.,Lu,F.I.,Su,H.M.,Wang,L.S.,Tsai,C.L.,&Hwang,P.P.(2003b).Effect of exogenous tryptophan on cannibalism,survival and growth in juvenile grouper,Epinephelus coioides.Aquaculture,218(1—4),251—263.https://doi.org/10.1016/S0044-8486(02)00503-3.

Hsu,Y.J.,Hou,C.Y.,Lin,S.J.,Kuo,W.C.,Lin,H.T.,&Lin,J.H.Y.(2013).The biofunction of orange-spotted grouper(Epinephelus coioides)CC chemokine ligand 4(CCL4)in innate and adaptive immunity.Fish&Shell fish Immunology,35(6),1891—1898.https://doi.org/10.1016/j.fsi.2013.09.020.

Huang,Y.,Cai,S.,Pang,H.,Jian,J.,&Wu,Z.(2017).Immunogenicity and efficacy of DNA vaccine encoding antigenic AcfA via addition of the molecular adjuvant Myd88 against Vibrio alginolyticus in Epinephelus coioides.Fish&Shell fish Immunology,66,71—77.https://doi.org/10.1016/j.fsi.2017.05.021.

Huang,H.Y.,Chen,Y.C.,Wang,P.C.,Tsai,M.A.,Yeh,S.C.,Liang,H.J.,et al.(2014a).Efficacy of a formalin-inactivated vaccine against Streptococcus iniae infection in the farmed grouper Epinephelus coioides by intraperitoneal immunization.Vaccine,32(51),7014—7020.https://doi.org/10.1016/j.vaccine.2014.08.039.

Huang,Y.H.,Huang,X.H.,Cai,J.,OuYang,Z.L.,Wei,S.N.,Wei,J.G.,et al.(2015).Identification of orange-spotted grouper(Epinephelus coioides)interferon regulatory factor 3 involved in antiviral immune response against fish RNA virus.Fish&Shell fish Immunology,42(2),345—352.https://doi.org/10.1016/j.fsi.2014.11.025.

Huang,X.,Huang,Y.,Cai,J.,Wei,S.,Ouyang,Z.,&Qin,Q.(2013).Molecular cloning,expression and functional analysis of ISG15 in orange-spotted grouper,Epinephelus coioides.Fish&Shell fish Immunology,34(5),1094—1102.https://doi.org/10.1016/j.fsi.2013.01.010.

Huang,Y.,Huang,X.,Yan,Y.,Cai,J.,Ouyang,Z.,Cui,H.,et al.(2011).Transcriptome analysis of orange-spotted grouper(Epinephelus coioides)spleen in response to Singapore grouper iridovirus.BMC Genomics,12(1),556.

Huang,W.,Liu,Q.Z.,Xie,J.F.,Wang,W.M.,Xiao,J.,Li,S.S.,et al.(2014b).Characterization of triploid hybrid groupers from interspecies hybridization(Epinephelus coioides♀×Epinephelus lanceolatus♂).Aquaculture Research.https://doi.org/10.1111/are.12672.n/a-n/a.

Hu,Y.,Li,A.,Xu,Y.,Jiang,B.,Lu,G.,&Luo,X.(2017).Transcriptomic variation of locally-infected skin of Epinephelus coioides reveals the mucosal immune mechanism against Cryptocaryonirritans.Fish&Shell fish Immunology,66,398—410.https://doi.org/10.1016/j.fsi.2017.05.042.

Hu,Y.L.,Xiang,L.X.,&Shao,J.Z.(2010).Identification and characterization of a novel immunoglobulin Z isotype in zebra fish:Implications for a distinct B cell receptor in lower vertebrates.Molecular Immunology,47(4),738—746.https://doi.org/10.1016/j.molimm.2009.10.010.

James,C.M.,Al-Thobaiti,S.A.,Rasem,B.M.,&Carlos,M.H.(1999).Potential of grouper hybrid(Epinephelus fuscoguttatus x E.polyphekadion)for aquaculture.Naga,the ICLARM Quaterly,22(1),19—23.

Kiriyakit,A.,Gallardo,W.G.,&Bart,A.N.(2011).Successful hybridization of groupers(Epinephelus coioides x Epinephelus lanceolatus)using cryopreserved sperm.Aquaculture,320(1—2),106—112.https://doi.org/10.1016/j.aquaculture.2011.05.012.

Kuan,Y.C.,Sheu,F.,Lee,G.C.,Tsai,M.W.,Hung,C.L.,&Nan,F.H.(2012).Administration of recombinant Reishi immunomodulatory protein(rLZ-8)diet enhances innate immune responses and elicits protection against nervous necrosis virus in grouper Epinephelus coioides.Fish&Shell fish Immunology,32(6),986—993.https://doi.org/10.1016/j.fsi.2012.02.008.

Lee,P.P.,Lin,Y.H.,Chen,M.C.,&Cheng,W.(2017b).Dietary administration of sodium alginate ameliorated stress and promoted immune resistance of grouper Epinephelus coioides under cold stress.Fish&Shell fish Immunology,65,127—135.https://doi.org/10.1016/j.fsi.2017.04.007.

Lee,M.-C.,Zhuo,L.-C.,&Lin,Y.-H.(2017a).Effects of dietary docosahexaenoic acid sources,microalgae meal and oil,on growth,fatty acid composition and docosahexaenoic acid retention of orange-spotted grouper,Epinephelus coioides.Aquaculture Research.https://doi.org/10.1111/are.13429.n/a-n/a.

Liang,H.,Huang,D.,Wu,Y.,Wang,C.,&Zhong,W.(2013).Effects of temperature and salinity on survival and food intake of grouper hybrid(Epinephelus lanceolatus x E.fuscoguttatus).Journal of Guangdong Ocean University,4,22—26.

Liao,I.C.,Su,H.M.,&Chang,E.Y.(2001).Techniques in fin fish larviculture in Taiwan.Aquaculture,200(1—2),1—31.https://doi.org/10.1016/S0044-8486(01)00692-5.

Li,Y.W.,Dan,X.M.,Zhang,T.W.,Luo,X.C.,&Li,A.X.(2011a).Immune-related genes expression pro file in orange-spotted grouper during exposure to Cryptocaryon irritans.Parasite Immunology,33(12),679—987.https://doi.org/10.1111/j.1365-3024.2011.01337.x.

Li,Y.W.,Li,X.,Wang,Z.,Mo,Z.Q.,Dan,X.M.,Luo,X.C.,et al.(2015).Orange-spotted grouper Epinephelus coioides Tak1:Molecular identi fi cation,expression analysis and functional study.Journal of Fish Biology,86(2),417—430.https://doi.org/10.1111/jfb.12550.

Li,Y.W.,Li,X.,Xiao,X.X.,Zhao,F.,Luo,X.C.,Dan,X.M.,et al.(2014).Molecular characterization and functional analysis of TRAF6 in orange-spotted grouper(Epinepheluscoioides).Developmental& ComparativeImmunology,44(1),217—225.https://doi.org/10.1016/j.dci.2013.12.011.

Li,Y.W.,Luo,X.C.,Dan,X.M.,Huang,X.Z.,Qiao,W.,Zhong,Z.P.,et al.(2011b).Orange-spotted grouper(Epinephelus coioides)TLR2,MyD88 and IL-1βinvolved in anti-Cryptocaryon irritans response.Fish&Shell fish Immunology,30(6),1230—1240.https://doi.org/10.1016/j.fsi.2011.04.012.

Li,Y.W.,Luo,X.C.,Dan,X.M.,Qiao,W.,Huang,X.Z.,&Li,A.X.(2012).Molecular cloning of orange-spotted grouper(Epinephelus coioides)TLR21 and expression analysis post Cryptocaryonirritans infection.Fish&Shell fish Immunology,32(3),476—481.https://doi.org/10.1016/j.fsi.2011.11.021.

Lim,L.S.,&Mukai,Y.(2014).Morphogenesis of sense organs and behavioural changes in larvae of the brown-marbled grouper Epinephelus fuscoguttatus(Forsskål).Marine and Freshwater Behaviour and Physiology,47(5),313—327.https://doi.org/10.1080/10236244.2014.940689.

Lim,L.M.,Senoo,S.,Siddiquee,S.,&Rodrigues,K.F.(2014).Molecular markers for parentage analysis in the grouper F1 hybrid Epinephelus coioides x Epinephelus lanceolatus(Actinopterygii:Perciformes:Serranidae).Acta Ichthyologica et Piscatoria,44(1),59—64.https://doi.org/10.3750/AIP2014.44.1.07.

Lin,C.Y.,Chen,Y.M.,Hsu,H.H.,Shiu,C.T.,Kuo,H.C.,&Chen,T.Y.(2012).Grouper(Epinephelus coioides)CXCR4 is expressed in response to pathogens infection and early stage of development.Developmental&Comparative Immunology,36(1),112—120.https://doi.org/10.1016/j.dci.2011.06.009.

Lin,K.,Ge,H.,Lin,Q.,Wu,J.,He,L.,Fang,Q.,et al.(2013).Molecular characterization and functional analysis of Toll-like receptor 3 gene in orange-spotted grouper(Epinephelus coioides). Gene, 527(1), 174—182. https://doi.org/10.1016/j.gene.2013.06.014.

Lin,H.Z.,Liu,Y.J.,He,J.G.,Zheng,W.H.,&Tian,L.X.(2007).Alternative vegetable lipid sources in diets for grouper,Epinephelus coioides(Hamilton):Effects on growth,and muscle and liver fatty acid composition.Aquaculture Research,38(15),1605—1611.https://doi.org/10.1111/j.1365-2109.2007.01811.x.

Liu,Q.H.,Xiao,Z.Z.,Wang,X.Y.,Xu,S.H.,Guan,S.G.,Xu,C.A.,et al.(2016).Sperm cryopreservation in different grouper subspecies and application in interspecific hybridization.Theriogenology,85(8),1399—1407.https://doi.org/10.1016/j.theriogenology.2015.12.023.

Low,C.F.,Mariana,N.S.,Maha,A.,Chee,H.Y.,&Fatimah,M.Y.(2015a).Non-immune-related genes and signalling pathways in spleen of Vibrio parahaemolyticus-infected Epinephelus fuscoguttatus(Forskal).Journal of Fish Diseases,38(8),761—764.https://doi.org/10.1111/jfd.12283.

Low,C.F.,Nor Shamsudin,M.,Abdullah,M.,Chee,H.Y.,&Aliyu-Paiko,M.(2015b).Experimental infection of brown-marbled grouper,Epinephelus fuscoguttatus(Forskal),with Vibrio parahaemolyticusidenti fies parvalbumin beta-2 subunit I,alpha-2-macroglobulin,nattectin and immunoglobulin light chain,differentially expressed in resistant grouper.Journal of Fish Diseases,38(1),17—25.https://doi.org/10.1111/jfd.12195.

Low,C.F.,Shamsudin,M.N.,Chee,H.Y.,Aliyu-Paiko,M.,&Idrus,E.S.(2014).Putative apolipoprotein A-I,natural killer cell enhancement factor and lysozymeg are involved in the early immune response of brown-marbled grouper,Epinephelus fuscoguttatus,Forsskål,to Vibrio alginolyticus.Journal of Fish Diseases,37(8),693—701.https://doi.org/10.1111/jfd.12153.

Luin,M.,Fui,C.F.,&Senoo,S.(2013).Sexual maturation and gonad development in Tiger grouper(Epinephelus fuscoguttatus)x Giant grouper(E.lanceolatus)hybrid.Aquaculture Research&Development,5(2),1—5.https://doi.org/10.4172/2155-9546.1000213.

Luo,S.W.,Cai,L.,Liu,Y.,&Wang,W.N.(2014).Functional analysis of a dietary recombinant fatty acid binding protein 10(FABP10)on the Epinephelus coioides in response to acute low temperature challenge.Fish&Shell fish Immunology,36(2),475—484.https://doi.org/10.1016/j.fsi.2013.12.028.

Luo,S.W.,Huang,Y.H.,Xie,F.X.,Huang,X.H.,Liu,Y.,Wang,W.N.,et al.(2015b).Molecular cloning,characterization and expression analysis of PPAR gamma in the orange-spotted grouper(Epinephelus coioides)after the Vibrio alginolyticus challenge.Fish&Shell fish Immunology,43(2),310—324.https://doi.org/10.1016/j.fsi.2015.01.003.

Luo,Z.,Liu,Y.J.,Mai,K.S.,Tian,L.X.,Liu,D.H.,&Tan,X.Y.(2004).Optimal dietary protein requirement of grouper Epinephelus coioides juveniles fed isoenergetic diets in floating net cages.Aquaculture Nutrition,10(4),247—252.https://doi.org/10.1111/j.1365-2095.2004.00296.x.

Luo,Z.H.I.,Liu,Y.J.,Mai,K.S.,Tian,L.X.,Liu,D.H.,Tan,X.Y.,et al.(2005).Effect of dietary lipid level on growth performance,feed utilization and body composition of grouper Epinephelus coioides juveniles fed isonitrogenous diets in floating netcages.Aquaculture International,13(3),257—269.https://doi.org/10.1007/s10499-004-2478-6.

Luo,S.,Xie,F.,Liu,Y.,&Wang,W.N.(2015a).Molecular cloning,characterization and expression analysis of complement component C8 beta in the orangespotted grouper(Epinephelus coioides)after the Vibrio alginolyticus challenge.Gene,558(2),291—298.https://doi.org/10.1016/j.gene.2015.01.018.

Lu,D.Q.,Yao,M.,Yi,S.B.,Li,Y.W.,Liu,X.C.,Zhang,Y.,et al.(2013).Soluble interleukin-1 receptor,a potential negative regulator of orange-spotted grouper Epinephelus coioides interleukin-1 system.Journal of Fish Biology,83(3),642—658.https://doi.org/10.1111/jfb.12202.

Lu,D.Q.,Yi,S.B.,Yao,M.,Li,Y.W.,Liu,X.C.,Zhang,Y.,et al.(2012).Identification and expression analysis of major histocompatibility complex IIB gene in orangespotted grouper Epinephelus coioides.Journal of Fish Biology,81(1),165—180.https://doi.org/10.1111/j.1095-8649.2012.03321.x.

Ma,K.Y.(2014).Patterns and processes of diversification in groupers(family:Epinephelidae).PhD.Townsville,Queensland,Australia:James Cook University.

Mamauag,R.E.P.,&Ragaza,J.A.(2017).Growth and feed performance,digestibility and acute stress response of juvenile grouper(Epinephelus fuscoguttatus)fed dietswith hydrolysatefrom milk fish offal.Aquaculture Research,48(4),1638—1647.https://doi.org/10.1111/are.12999.

Mat Ali,H.,Om,A.D.,Idris,S.M.,Mustafa,S.,&Teoh,P.N.(2006).Improved artificial breeding techniques of Tiger grouper(Epinephelus fuscoguttatus).https://doi.org/10.13140/2.1.3248.8967.

Ma,H.L.,Xie,J.F.,Weng,S.P.,Zhou,T.H.,&He,J.G.(2012).Co-infection of megalocytivirus and viral nervous necrosis virus in a very severe mass mortality of juvenile orange-spotted groupers(Epinephelus coioides).Aquaculture,358—359,170—175.https://doi.org/10.1016/j.aquaculture.2012.06.032.

Millamena,O.M.(2002).Replacement of fish meal by animal by-product meals in a practical diet for grow-out culture of grouper Epinephelus coioides.Aquaculture,204(1—2),75—84.https://doi.org/10.1016/S0044-8486(01)00629-9.

Millamena,O.M.,&Golez,N.V.(2001).Evaluation of processed meat solubles as replacement for fish meal in diet for juvenile grouper Epinephelus coioides(Hamilton).Aquaculture Research,32,281—287.https://doi.org/10.1046/j.1355-557x.2001.00041.x.

Mo,Z.Q.,Wang,J.L.,Yang,M.,Ni,L.Y.,Wang,H.Q.,Lao,G.F.,et al.(2017).Characterization and expression analysis of grouper(Epinephelus coioides)costimulatory molecules CD83 and CD80/86 post Cryptocaryon irritans infection.Fish & Shell fish Immunology,67,467—474.https://doi.org/10.1016/j.fsi.2017.05.064.

Muhammadar,A.A.,Mazlan,A.G.,Samat,A.,Asmawati,M.S.,Muchlisin,Z.A.,Rimmer,M.,et al.(2014).Growth,survival and feed conversion of juvenile tiger grouper Epinephelus fuscoguttatus in different salinity regimes.AACL Bio flux,7(4),241—247.

Muhammadar,A.A.,Mazlan,A.G.,Samat,A.,Muchlisin,Z.A.,&Simon,K.D.(2011).Crude protein and amino acids content in some common feeds of tiger grouper(Epinephelus fuscoguttatus)juvenile.AACL Bio flux,4(4),499—504.

Muhammadar,A.A.,Mazlan,A.G.,Samat,A.,Simon,K.D.,Asmawati,M.S.,Muchlisin,Z.A.,et al.(2012).Feed digestion rates of tiger grouper(Epinephelus fuscoguttatus)juvenile.AACL Bio flux,5(5),356—360.

Mukai,Y.,Lim,L.S.,Lu,K.C.,Abdul Rashid,M.K.,&Saad,S.(2012a).Light intensity requirements for feeding behaviour by the brown-marbled grouper,Epinephelus fuscoguttatus.Sains Malaysiana,41(10),1193—1196.

Mukai,Y.,Lim,L.S.,&Saad,S.(2012b).Retinomotor response in larvae of brownmarbled grouper,Epinephelus fuscoguttatus.Journal of Fisheries and Aquatic Science,7(3),233—239.https://doi.org/10.3923/jfas.2012.233.239.

Mukai,Y.,&Seng Lim,L.(2016).Morphogenesis of free neuromasts in the larvae of brown-marbled grouper Epinephelus fuscoguttatus.Marine and Freshwater Behaviour and Physiology, 49(3), 159—171. https://doi.org/10.1080/10236244.2016.1146447.

Mukai,Y.,Tan,N.H.,Rosli,M.K.,&Liau,C.F.(2016).Demand feeding system using an infrared light sensor for brown-marbled grouper juveniles,Epinephelus fuscoguttatus.Sains Malaysiana,45(5),729—733.

Mustafa,S.,Hajini,M.H.,Senoo,S.,&Kian,A.Y.S.(2015).Conditioning of broodstock of tiger grouper,Epinephelus fuscoguttatus,in a recirculating aquaculture system.Aquaculture Research,2,117—119.https://doi.org/10.1016/j.aqrep.2015.09.004.

Mustafa,S.,Senoo,S.,&Luin,M.(2013).Response of pure stock of coral reef tiger grouper,and hybrid grouper to simulated ocean acidification.The International Journal of Climate Change:Impacts and Responses,5(1),47—54.

Niu,J.,Liu,Y.J.,Tian,L.X.,Mai,K.S.,Zhou,Q.C.,Yang,H.J.,et al.(2007).Maize oil can replace fish oil in the diet of grouper postlarvae(Epinephelus coioides)without adversely affecting growth or fatty acid composition.American Journal of Agricultural and Biological Sciences,2(2),81—87.

Ni,L.Y.,Zhou,L.,Wang,H.Q.,Luo,X.C.,Dan,X.M.,&Li,Y.W.(2017).Identification and expression analysis of three XCR1-like receptors from Epinephelus coioides after Cryptocaryon irritans infection.Fish&Shell fish Immunology,67,95—102.https://doi.org/10.1016/j.fsi.2017.06.010.

Ou-Yang,Z.L.,Wang,P.R.,Huang,X.H.,Cai,J.,Huang,Y.H.,Wei,S.N.,et al.(2012).Immunogenicity and protective effects of inactivated Singapore grouper iridovirus(SGIV)vaccines in orange-spotted grouper,Epinephelus coioides.Developmental&Comparative Immunology,38(2),254—261.https://doi.org/10.1016/j.dci.2012.07.004.

Pakingking,R.,Jr.,Bautista,N.B.,de Jesus-Ayson,E.G.,&Reyes,O.(2010).Protective immunity against viral nervous necrosis(VNN)in brown-marbled grouper(Epinephelus fuscogutattus)following vaccination with inactivated betanodavirus.Fish&Shell fish Immunology,28(4),525—533.https://doi.org/10.1016/j.fsi.2009.12.004.

Pan,C.Y.,Huang,T.C.,Wang,Y.D.,Yeh,Y.C.,Hui,C.F.,&Chen,J.Y.(2012).Oral administration of recombinant epinecidin-1 protected grouper(Epinephelus coioides)and zebra fish(Daniorerio)from Vibrio vulnificus infection and enhanced immune-related gene expressions.Fish&Shell fish Immunology,32(6),947—957.https://doi.org/10.1016/j.fsi.2012.01.023.

Parra,D.,Reyes-Lopez,F.E.,&Tort,L.(2015).Mucosal immunity and B cells in teleosts:Effect of vaccination and stress.Frontiers in Immunology,6,354.https://doi.org/10.3389/fimmu.2015.00354.

Qu,H.D.,Chen,B.,Peng,H.,&Wang,K.J.(2013).Molecular cloning,recombinant expression,and antimicrobial activity of ec-hepcidin3,a new four-cysteine hepcidinisoform from Epinepheluscoioides.Bioscience Biotechnology &Biochemistry,77(1),103—110.https://doi.org/10.1271/bbb.120600.

Rahim,N.S.N.,Esa,Y.,&Arshad,A.(2016).Molecular phylogeny of some Malaysian groupers(Subfamily:Epinephelinae,Family:Serranidae)inferred from mitochondrial and nuclear gene sequences.Journal of Security Sector Management,11(2),1—10.

Reyes,O.S.,Duray,M.N.,Santiago,C.B.,&Ricci,M.(2011).Growth and survival of grouper Epinephelus coioides(Hamilton)larvae fed free-living nematode Panagrellus redivivus at first feeding.Aquaculture International,19(1),155—164.https://doi.org/10.1007/s10499-010-9349-0.

Rimmer,M.A.,Phillips,M.J.,&Yamamoto,K.(2007).Recent developments in aquaculture of groupers in the Asia-Pacific region.Vol.ACIAR Working Paper No.63,pp.77—84.In B.Johnston(Ed.),Economics and market analysis of the live reef- fish trade in the Asia-Pacific Region.Canberra ACT 2601,Australia:Australian Centre for International Agricultural Research.

Samad,A.P.A.,Santoso,U.,Lee,M.C.,&Nan,F.H.(2014).Effects of dietary katuk(Sauropus androgynus L.Merr.)on growth,non-specific immune and diseases resistance against Vibrio alginolyticus infection in grouper Epinephelus coioides.Fish&Shellfish Immunology,36(2),582—589.https://doi.org/10.1016/j.fsi.2013.11.011.

Seth,S.N.M.,Tan,N.H.,Rosli,M.K.,Saad,S.,Noor,N.M.,&Mukai,Y.(2014).Egg hatching rates of brown-marbled grouper,Epinephelus fuscoguttatus under different light wavelengths and intensities.Malaysian Journal of Science,33(2),150—154.

Shapawi,R.,Ebi,I.,Yong,A.S.K.,&Ng,W.K.(2014).Optimizing the growth performance of brown-marbled grouper,Epinephelus fuscoguttatus(Forsskål),by varying the proportion of dietary protein and lipid levels.Animal Feed Science and Technology,191,98—105.

Shiu,Y.L.,Hsieh,S.L.,Guei,W.C.,Tsai,Y.T.,Chiu,C.H.,&Liu,C.H.(2015).Using Bacillus subtilis E20-fermented soybean meal as replacement for fish meal in the diet of orange-spotted grouper(Epinephelus coioides,Hamilton).Aquaculture Research,46(6),1403—1416.https://doi.org/10.1111/are.12294.

Shi,Y.,Zhao,Z.,Hong,X.Y.,Chen,K.C.,&Zhu,X.P.(2014).Characterization and functional analysis of voltage-dependent anion channel 1(VDAC1)from orange-spotted grouper(Epinephelus coioides).Journal of Biochemical and Molecular Toxicology,28(7),292—301.https://doi.org/10.1002/jbt.21565.

Sugama,K.,Rimmer,M.A.,Ismi,S.,Koesharyani,I.,Suwirya,K.,Giri,N.A.,et al.(2012).Hatchery management of tiger grouper(Epinephelus fuscoguttatus):A best-practice manual.ACIAR Monograph No.149.Canberra:Australian Centre for International Agricultural Research.

Sun,Y.,Huang,Y.,Hu,G.,Zhang,X.,Ruan,Z.,Zhao,X.,et al.(2016).Comparative transcriptomic study of muscle provides new insights into the growth superiority of a novel grouper hybrid.PLoS One,11(12),e0168802.https://doi.org/10.1371/journal.pone.0168802.

Sun,Y.Z.,Xia,H.Q.,Yang,H.L.,Wang,Y.L.,&Zou,W.C.(2014).TLR2 signaling may play a key role in the probiotic modulation of intestinal microbiota in grouper Epinephelus coioides.Aquaculture,430(0),50—56.https://doi.org/10.1016/j.aquaculture.2014.03.042.

Sun,Y.Z.,Yang,H.L.,Ling,Z.C.,&Ye,J.D.(2015).Microbial communities associated with early stages of intensively reared orange-spotted grouper(Epinephelus coioides).Aquaculture Research,46(1),131—140. https://doi.org/10.1111/are.12167.

Sutthinon,P.,Thongprajukaew,K.,Saekhow,S.,&Ketmanee,R.(2015).Juvenile hybrid grouper(Epinephelus coioides×E.lanceolatus)are euryhaline and can grow in a wide range of salinities.Aquaculture International,23(2),671—682.https://doi.org/10.1007/s10499-014-9845-8.

Toledo,J.D.,Caberoy,N.B.,Quinitio,G.F.,Choresca,C.H.,&Nakagawa,H.(2002).Effects of salinity,aeration and light intensity on oil globule absorption,feeding incidence,growth and survival of early-stage grouper Epinephelus coioides larvae.Fisheries Science,68(3),478—483.https://doi.org/10.1046/j.1444-2906.2002.00451.x.

Wang,T.-Y.,Chen,Y.-M.,&Chen,T.-Y.(2016).Molecular cloning of orange-spotted grouper(Epinephelus coioides)heat shock transcription factor 1 isoforms and characterization of their expressions in response to nodavirus.Fish&Shell fish Immunology,59(Supplement C),123—136.https://doi.org/10.1016/j.fsi.2016.10.032.

Wang,T.,Cheng,Y.Z.,Liu,Z.P.,&Long,X.H.(2015).Effects of light intensity on husbandry parameters,digestive enzymes and whole-body composition of juvenile Epinephelus coioides reared in artificial sea water.Aquaculture Research,46(4),884—892.https://doi.org/10.1111/are.12241.

Wang,J.T.,Jiang,Y.D.,Han,T.,Li,X.Y.,Wang,Y.,&Liu,Y.J.(2017a).Effects of dietary carbohydrate-to-lipid ratios on growth and body composition of orangespotted grouper Epinephelus coioides.North American Journal of Aquaculture,79(1),1—7.https://doi.org/10.1080/15222055.2016.1194924.

Wang,Y.-r.,Wang,L.,Zhang,C.-x.,&Song,K.(2017b).Effects of substituting fishmeal with soybean meal on growth performance and intestinal morphology in orange-spotted grouper(Epinephelus coioides).Aquaculture Research,5(Supplement C),52—57.https://doi.org/10.1016/j.aqrep.2016.12.005.

Wei,J.G.,Guo,M.L.,Cui,H.C.,Yan,Y.,Ouyang,Z.L.,&Qin,Q.W.(2011a).A new leukocyte cell-derived chemotaxin-2 from marine fish grouper,Epinephelus coioides:Molecular cloning and expression analysis.Fish&Shell fish Immunology,31(4),600—605.https://doi.org/10.1016/j.fsi.2011.07.002.

Wei,J.G.,Guo,M.L.,Ji,H.S.,&Qin,Q.W.(2013a).Molecular cloning,characterization of one key molecule of teleost innate immunity from orange-spotted grouper(Epinephelus coioides):Serum amyloid A.Fish&Shell fish Immunology,34(1),296—304.https://doi.org/10.1016/j.fsi.2012.11.014.

Wei,J.G.,Guo,M.L.,Ji,H.S.,Yan,Y.,Ouyang,Z.L.,Huang,X.H.,et al.(2012a).Cloning,characterization,and expression analysis of a thioredoxin from orangespotted grouper(Epinephelus coioides).Developmental&Comparative Immunology,38(1),108—116.https://doi.org/10.1016/j.dci.2012.04.011.

Wei,S.N.,Huang,Y.H.,Cai,J.,Huang,X.H.,Fu,J.,&Qin,Q.W.(2012b).Molecular cloning and characterization of c-type lysozyme gene in orange-spotted grouper,Epinephelus coioides.Fish&Shell fish Immunology,33(2),186—196.https://doi.org/10.1016/j.fsi.2012.03.027.

Wei,S.N.,Huang,Y.H.,Huang,X.H.,Cai,J.,Wei,J.G.,Li,P.F.,et al.(2014a).Molecular cloning and characterization of a new G-type lysozyme gene(Ec-lysG)in orange-spotted grouper,Epinephelus coioides.Developmental&Comparative Immunology,46(2),401—412.https://doi.org/10.1016/j.dci.2014.05.006.

Wei,S.N.,Huang,Y.H.,Huang,X.H.,Cai,J.,Yan,Y.,Guo,C.Y.,et al.(2014b).Characterization of cathepsin B gene from orange-spotted grouper,Epinephelus coioides involved in SGIV infection.Fish&Shell fish Immunology,36(1),194—205.https://doi.org/10.1016/j.fsi.2013.11.006.

Wei,S.N.,Huang,Y.H.,Huang,X.H.,&Qin,Q.W.(2015).Characterization of c-Jun from orange-spotted grouper,Epinephelus coioides involved in SGIV infection.Fish&Shell fish Immunology,43(1),230—240.https://doi.org/10.1016/j.fsi.2014.12.033.

Wei,J.G.,Ji,H.S.,Guo,M.L.,Yan,Y.,&Qin,Q.W.(2013b).Identification and characterization of TRP14,a thioredoxin-related protein of 14 kDa from oranges potted grouper,Epinephelus coioides.Fish&Shellfish Immunology,35(5),1670—1676.https://doi.org/10.1016/j.fsi.2013.08.010.

Wei,Y.C.,Pan,T.S.,Chang,M.X.,Huang,B.,Xu,Z.,Luo,T.R.,et al.(2011b).Cloning and expression of Toll-like receptors 1 and 2 from a teleost fish,the orangespotted grouper Epinephelus coioides.Veterinary Immunology and Immunopathology,141(3—4),173—182.https://doi.org/10.1016/j.vetimm.2011.02.016.

Wei,J.,Zhang,X.,Zang,S.,&Qin,Q.(2017).Expression and functional characterization of TRIF in orange-spotted grouper(Epinephelus coioides).Fish&Shell fish Immunology,71,295—304.https://doi.org/10.1016/j.fsi.2017.09.063.

Wu,M.S.,Chen,C.W.,Liu,Y.C.,Huang,H.H.,Lin,C.H.,Tzeng,C.S.,et al.(2012).Transcriptional analysis of orange-spotted grouper reacting to experimental grouper iridovirus infection.Developmental&Comparative Immunology,37(2),233—242.https://doi.org/10.1016/j.dci.2012.04.002.

Yeh,S.P.,Chang,C.A.,Chang,C.Y.,Liu,C.H.,&Cheng,W.(2008).Dietary sodium alginate administration affects fingerling growth and resistance to Streptococcus sp.and iridovirus,and juvenile non-specific immune responses of the oranges potted grouper,Epinephelus coioides.Fish&Shell fish Immunology,25(1—2),19—27.https://doi.org/10.1016/j.fsi.2007.11.011.

Yin,G.,Li,W.,Lin,Q.,Lin,X.,Lin,J.,Zhu,Q.,et al.(2014).Dietary administration of laminarin improves the growth performance and immune responses in Epinephelus coioides.Fish&Shell fish Immunology,41(2),402—406.https://doi.org/10.1016/j.fsi.2014.09.027.

Yokoyama,S.,Koshio,S.,Takakura,N.,Oshida,K.,Ishikawa,M.,Gallardo-Cigarroa,F.J.,et al.(2006).Effect of dietary bovine lactoferrin on growth response,tolerance to air exposure and low salinity stress conditions in orange spotted grouper Epinephelus coioides.Aquaculture,255(1—4),507—513.https://doi.org/10.1016/j.aquaculture.2005.12.001.

Zhang,Y.A.,Salinas,I.,Li,J.,Parra,D.,Bjork,S.,Xu,Z.,et al.(2010).IgT,a primitive immunoglobulin class specialized in mucosal immunity.Nature Immunology,11(9),827—835.https://doi.org/10.1038/ni.1913.

Zhou,J.G.,Wei,J.G.,Xu,D.,Cui,H.C.,Yan,Y.,Ou-Yang,Z.L.,et al.(2011).Molecular cloning and characterization of two novel hepcidins from orange-spotted grouper,Epinephelus coioides.Fish&Shell fish Immunology,30(2),559—568.https://doi.org/10.1016/j.fsi.2010.11.021.

Zhuang,Z.R.,Yang,X.D.,Huang,X.Z.,Gu,H.X.,Wei,H.Y.,He,Y.J.,et al.(2017).Three new piscidins from orange-spotted grouper(Epinephelus coioides):Phylogeny,expression and functional characterization.Fish&Shell fish Immunology,66,240—253.https://doi.org/10.1016/j.fsi.2017.04.011.