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This paper was submitted by the faculty of FAU’s Harbor Branch Oceanographic Institute.

Notice: ©2003 World Aquaculture Society. This published manuscript is available at www.was.org and may be cited as: Tucker, J. W., Jr. (2003). Grouper culture. World Aquaculture Magazine, 34(3), 32-36, 38-39, 57-59.

JOHN W. TUCKER, JR. 1,2

Groupers are classified in 14 genera most species continueto stay nearsmall grouper (E. akaara), yellow grouper (E. of the subfamily Epinephelinae, which caves for security. Wild grouper larvae at awoara), squaretail grouper (E. comprises at least half of the 449 species first eat copepods and other small zoop­ areolatus), and king grouper. Minor spe­ in the family Serranidae. Throughout lankton, then larger crustaceans like am­ cies are: blackspotted grouper (E. mostwarmandtemperatemarineregions, phipods and rnysidshrimp. Wildjuveniles amblycephalus), brownmarbled grouper serranids are highly valued for food, and and adults eat mainly fish, crabs, shrimp, (E.fllscogllftatus, Figures I and 3), sixbar both small and large species are kept in mantis shrimp, lobsters, and molluscs. grouper (E. sexfasciatus), bluespotted aquariums. Maximum size ranges from More than 20 grouper species have grouper (E. trimaculatus), longfin grou­ about 12em total length (TL) for western been raised commercially, mostly by per (E. quoyanusy, kelp grouper (E. Atlantic Serranus species and the Pacific growing out captured wildjuveniles in the bruneus), polka-dot grouper (Cromileptes creole-fish (Paratuhias colonusi to more Southeast Asian region. FAa (2002) re­ altivelis),leopardcoraltrout tPlectropomus than 4 m TL (~440kg) for the king grou­ ported that 9,488 tons of groupers and sea Ieopardus, Figure 4), barred-cheek per, giant grouper, groper, or brindlebass basses worth US$65,339,000 were grown coraltrout (P. maculatus), squaretail (Epinephelus lanceolatus). out in Taiwan (5,053), Thailand (2,150), coraltrout (P. areolatus), honeycomb Ages (months)atwhichsome western Malaysia (1,217), Indonesia (1,159), grouper (E. merra), camouflage grouper Atlantic serranids reach 454 g in nature Hong Kong (523), Philippines (167), (E. polyphekadion), and greasy grouper are: Goliath grouper (E. itajara) about 12, Singapore (Ill), Kuwait (6) and Brazil (E. tauvina). For farming in the southeast­ black grouper (Mycteraperca bonaci) 17, (2) during 2000. Sadovy (2001) estimated ern U.S. and Caribbean region, Nassau gag grouper (M. micralepis) 18, red grou­ that for the late 1990s about 60 million groupers (Figure 5), gags (Figures 6 and per (E. moria) 27, and black sea bass juveniles grown out per year resulted in 24), black groupers (Figure 7), and (Centropristis striata, subfamily 23,000 tons of live table-size groupers Goliath groupers (Figure 8) seem to have . Serraninae) 51. Nassau groupers (E. sold in Southeast Asia; however, at least good potential. Dusky tEpinephelus striatus) reach 500 mm (about 2.5 kg) in hundreds of millions of wild grouper ju­ marginatusy and white groupers 4-5 yr and Goliath groupers reach 500 ram veniles were caught and sold each year, tEpinephelus aeneus) have been investi­ (about 2.7 kg) in about 2 yr. Maximum so mortality from capture and transporta­ gated in the Mediterranean. reported sizes are: 1,220 ram TL and tion had to be very high and wasteful. De­ Wild groupers tend to be very easy to about 27 kg for Nassau groupers, 1,518 spite improvements in recentyears, only catch, especially species that form large mm for black groupers, 1,290 mm for 20,000-80,000 juveniles are produced aggregations for spawning like the Nassau gags and about 2,500 ram and 320 kg for annually by hatcheries throughout the re­ grouper. This grouper historically was the Goliath groupers. Nassau groupers live gion, not counting those in Taiwan most important through most of the Car­ for at least 29 yr, black groupers 33 yr, (Sadovy 2001). About two-thirds of the ibbean islands and coastal reefs, but has gags 21-22 yr, red groupers 25 yr and groupers grown outin Taiwan were from beenoverfishedtocommercial extinction Goliath groupers 37 yr. hatcheries. In 1998,about half of the grou­ in manyareas. Both commercial andrec­ Juveniles and adults of some grouper pers farmed there had been raised from reational harvests are now prohibited in species live in coastal waters and estuar­ wildjuveniles (Cesar et al. 2000).In 2000, the U.S. The gag and red grouper, because ies, but others prefer the cleaner waters Taiwanese hatcheries produced 300,000 of their abundance and availability to the of offshore reefs. Eggs are planktonic ­ brownmarbled groupers and 2 million fishery, are economically the most impor­ single. non-adhesive and buoyant at nor­ king groupers (Chan 2001). King grou­ tant species in the U.S. They and many mal salinities. Larvae of most species per culture has just been developed in the other grouper species throughout the spend at least their first few weeks drift­ lastfew years andis continuing atastrong world have been overfished, leading to re­ ing with the oceanic plankton. As they rate. ducednumbers andreduced averagesize. become juveniles, groupers settle to the The primary farmed Asian species Once grouper production reaches a high bottom, usually in shallow water, where (Sadovy 2001) have been: orangespotted enough level, aquaculture will help pro­ they can find hiding places. Then, until orestuary grouper (E. coioides, Figure I) tect wild stocks by reducingfishing pres­ severalcentimeterslong, theyhide almost and Malabar grouper (E. malabaricus, sure. constantly. Theirboldness increases with Figure 2). Other major species are: In some areas wherewildjuveniles are size and they move to deeper water, but duskytailgrouper (E. bleekeri), redspotted caught for growout, supplies (catch-per-

32 SEPTEMBER 2003 ()pf :<'CI Ag. 2. Malabar grouper (Epinephelus malabaricus) broodstock in Thailand. (Photo by John Tucker)

Fig. 1. Asian red snapper (lutjanus argentimaculatus), orangespotted Fig. 3. Female brownmarbled grouper grouper (Epinephelus coioides) and (Epinephelus fuscoguttatus) two days brownmarbled grouper (Epinephelus before spawning at Palau. (Photo by fuscoguttatus) being grown out in John Tucker) Singapore. (Photo by John Tucker)

Fig. 4. Leopard coraltrout (plectropomus leopard us) at Palau. (Photo by John Tucker)

Fig. 6. Gag (Mycteroperca microlepis) in Florida. (Photo by John Tucker)

Fig. 5. Nassau grouper (Epinephelus striatus) at Grand Cayman. (Photo by John Tucker) Fig. 7. Black grouper (Mycteroperca bonaci) at Grand Cayman. (Photo by John Tucker)

Fig. 8. Goliath grouper (Epinephelus itajara) in Florida. (Photo by Lewis Bullock, Florida Fish and Wildlife Conservation Commission)

WORLD AQUACULTURE 33 unit-of-effort) have decreased in recent years (Johannes et at. 1998). especially near Hong Kong, Taiwan, and China (Sadovy 200 I). Possible fac­ tors include not only overfish­ ing of juveniles but also over­ fishing of adults, habitat loss, toxic pollutants, and popula­ tion cycle variations. In other areas, supplies of juveniles Fig. 9. Concrete raceways (3.0 x 12.2 x 1.0 m Fig. 10. Spawning cage (5 x 5 x 3 m deep) in deep) in which wild and reared Nassau which polka-dot groupers (Cromileptes altivelis) have been relatively constant, groupers (Epinephelus striatus) spawned in spawned, between Singapore and Mataysia. despite 20 or more years of col­ Florida. (Photo by John Tucker) (Photo by John Tucker) lecting. As groupers grow in nature, their numbers naturally decrease. Harvesting smallju­ veniles has less impact than harvesting a similarnumberof larger fish, and is less likely to be a determining factor of population size. The more that a given grouper population is limited by predation or lack of habitat for fish larger than those' caught for growout, the less the impact of such catches will be'. If heavy losses natu­ Fig. 11. A 26-m' concrete larvai rearing tank at Fig. 12. Concrete iarval rearing tanks, each 50 rally occur after the collected the National institute of Coastai Aquacuiture, m', in Japan. (Photo by John Tucker) stage, then protecting a num- Thailand. (Photo by John Tucker) ber of the fish on farms actu­ ally could increase the total numbers available for harvest. At least, if collection of mod­ erate numbers is small com­ pared to those lost to natural mortality, significant losses of wild stocks would not result. Therefore, traditional grouper fanning in Asia (i.e. wild grou­ pers grown in ponds or cages) has been encouraged by some environmental organizations. Fig. 13.A 50-m' concrete iarvai rearing tank in Fig. 14. Concrete larvai rearing tanks in Taiwan, But at the same time, grouper Japan (from the group in Fig. 12). (Photo by usuaity shaded when iarvae are stocked. hatchery technology needs to John Tucker) (Photo by John Tucker) be perfected, because the wild supply does fluctuate and there is no guarantee that it will continue in­ delinitely. Survival of collectedjuveniles also must be improved. Shipping of infected wild or reared juveniles to distant growout areas has Fig. 15. The main bay of transferred diseases, especially viral and Lamma Island (southwest at parasitic ones. There are strong move­ Hong Kong, in background), ments to have national and international which contains houseboats regulations and agreements enacted to and a fairiy iarge number oi reduce and eventually prevent such prob­ fish cages. (Pilato by Joiln Tucker) lems. In 1998, there were about 600 grouper

34 SEPTEMBER 2003 hatcheries and farms in Taiwan, produc­ and larger ponds (Figure ing 5,000-7,000 tons/yr. 90 percent of 16) have been used for which was orangespotted and Malabar growout. Good environ­ groupers (Cesar et al. 2000). The large mental control is espe­ number of participants, strong govern­ cially importaut for both ment support, intense research and spe­ broodstock and larvae, cialization, availability of large areas of but not as critical for the coastal land and mass production of eggs other stages. are factors contributing to the Taiwanese Brood'locl, success. Most groupers that Culture Methods have been studied will mature within 2-6 yr Facilities (Tucker 1998). Many Fig. 16. A pond used lor growing out groupers In Taiwan. Saltwater is needed for broodfish, eggs serranids are proto­ (Photo by John Tucker) and larvae. Juveniles and adults of many gynous hermaphrodites species can live in brackish but not fresh­ (i.e. most individuals water. Groupers have spawned voluntar­ mature first as females and some of them usually involve small numbers offish (e.g. ily in fiberglass, concrete (Figure 9), or become males later). Some of those spe­ 2-5). Small serranidsoften spawn in pairs plastic tanks with volumes of 1-21,200 cies, as a rule, change from female to male without aggregating. A few of the small nr', concrete ponds of 1.8-860 m' and as they grow older, while others might serranids are simultaneous hermaphro­ cages (Figure 10) of 26-75 m' (Tucker change only if thereis a shortage of males. dites (male and female at the same time) 1994, 1998). Larvae have been reared In nature, Nassau groupers typically but self-fertilization seems to be rare. mainly in fiberglass or concrete tanks spawn in large distinct aggregations (hun­ Broodstock can be captured or reared. (Figures 11-14) holding 1-60 m ' and dreds to thousands offish) with a sex ra­ Most groupers studied have quickly sometimes in concrete ponds of up to 500 tio near 1:1. Gags spawn in harems, fre­ adapted to captivity. Adults usually are m3; while a minimum of 3.5 m3 is good, quently within aggregations, with a sex captured by traps or hook and line. With 7 m3 or larger is better. Tanks (Figure 9) ratio often near I male: 10 females. For protogynous hermaphrodites, sex control and cages (Figure IS) up to at least 75 m' both species, individual spawning events sometimes is considered necessary to en-

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WORLD AQUACULTURE 35 sure an optimal male:female ratio for maximizing egg produc­ tion. If males are difficult to collect or do not occur in reared broodstock when the females have become mature, sex-reversal offemales with dietary or injected methyltestosterone could pro­ vide the needed males. When too many females could become males, suppression of sex-reversal has been accomplished by administering female hormoneslike estradiolor by maintaining enough large males in the tank. With simultaneous hermaphro­ dites, mature fish of similar size usually can be paired. Voluntary spawning of captive groupers has occurred mostly with well-fed uncrowded fish during the natural spawning sea­ son underconditions of ambienttemperature andpartial or total natural light (Tucker 1994,1998). Day length seems to be a less important stimulus for spawning than temperature. More than Fig. 17. Nassau groupers (Epinephelus striatus) spawning in a 30 serranid species bave spawned voluntarily in captivity, with concrete raceway (3.0 x 12.2 x 1.0 m deep) in Florida. In the groupers spawning in 1- to 21,200-m' tanks or ponds and 26- to center are a female flanked by two males; at the lower right are 75-m3 cages. Eggs are collected in automatic strainers or with two females that have ovulated but are not yet spawning. soft, fine dipnets. It should be kept in mind that some species (Photo by John Tucker) spawn near certain moon phases and others spawn any day of the lunar month. With good timing and luck, groupers can be caughtjust before spawning and held in tanks or cages for up to a few days until they ovulate naturally. The eggs are stripped, or rarely, the fish are left in the tank for voluntary or accidental fertilization to occur, if the males are running ripe. A 6 kg female Nassau grouper can produce about 900,000 eggs per day by natural or hormone-induced ovulation and 3.3 million eggs in a 4 day period when spawning voluntarily (Fig­ ures 9 and 17). Hormone-induced ovulation of ripe wild or captive groupers and sea basses generally is reliable (Tucker 1994, 1998). Fig. 18. Giving an More than 31 serranid species have been induced to ovu­ intramuscular late (Figure 18). Typically, a female with fully yolked 00- injection to a female cytes (immature eggs) will ovulate (release mature eggs squaretall coraftrout into the centers of the ovaries) within 24-72 hours (usu­ (plectropomus areoia!us) in Palau to ally 36-50 hours) after tbe first of 1-3 injections of 500­ induce ovulation. 1,000 ill human chorionic gonadotropinikg body weight. (Photo by John Similar results have been obtained for several species given Tucker) 1-3 injections of 10-50 uggonadotropin releasing hormone analog (GnRHa)ikg body weight, and GnRHa implants also have worked. If newly caught broodfish are used, the hor­ mone should be administered as soon after capture as pos­ sible to limit stress effects on oocyte development. For six grouper species with egg diameters of 800-1,000 1JI11,the Fig. 19. Stripping eggs from a squaretall minimum effective oocyte diameter, as seen in biopsy coraftrout (plec!ropomus areola!us) in Palau. samples, before injection was in the range 41-61 percent (Photo by John Tucker) of the fertilized egg diameter. Ovarian biopsies are not nec­ essary if external characteristics can be relied upon as in­ dicators of oocyte development. Females are handled as little as possible, but are monitored closely for swollen abdo­ men, protruding genital papilla, stretching of the membrane hold­ ing eggs in and spawning coloration. They are checked more often, such as once an hour, just before the predicted time of ovulation (Figure 19). For Nassau groupers, the time from ovu­ lation to over-ripeness (deterioration of eggs) is only 1-2 hours at 26'C. Transparency, buoyancy, roundness, normal egg size, size uniformity, lack of stickiness, possession of a single oil globule (Continued 0/1 page 38)

36 SEPTEMBER 2003 larvaemight appearexhausted or stunned, swim erratically, drift with the current and/ornot feed well. Earlygrouperlarvae, es­ pecially when stressed,sometimes exude a largeamountof mu­ cus, which can cause them to stick to each other, to the surface film, or to solid objects. Gorging on Anemia is another source of mortality for mid­ stage larvae, andcannibalism amongearlyjuveniles is a poten­ tial problem. Gorgingcan be minimized by adding the Artemia in small amounts and by feeding rotifers and copepods for at least severaldays afterAnemia are started. Cannibalism can be minimized by feeding the fish well, weaning them as soon as possible and removing extralarge fish regularly (grading). Fig. 20. A nursery cage (1 x 1 x 1m) used for Nursery groupers in Singapore. (Photo by John Tucker) In the Philippines and other areas, when fish are too small to stock directlyin growoutponds,the earlyjuveniles areraisedin and normal oil globule size are initial signs of quality. High fer­ cages (Figure 20) in the ponds, usually from 20-30 mm to 50­ tilizationrate, normalcell division, high hatchingrateand suc­ 100 mm (Figures 21-23) in about 30-45 days (Baliao et at. 1998). cessful first feeding aresubsequent signs. Usually,eggs aretrans­ About 60 fish/m' are stocked in the cages (size range 4 x 2 x 1.5 ferred to rearing tanks just before hatching, or larvae are m to 8 x 4 x 1.5 m, with 0.5-cm mesh). transferred just before first feeding, but it is best to avoid han­ In Taiwan, up to 2,000juveniles are raised per cage (1.2 x 0.8 dling of grouper larvae. x 0.8 m) in small ponds (about 100 m2) for 1-3 months until they Hatchery reach about 6 cm TL (Rimmer 1998). Larger ponds are used mainly for over-wintering. Pondtemperatures areabout26"C in Known egg diameters are in the 0.8 to 1.0 mm range and summer andabout20-24"Cin winter. Tolimit cannibalism, grad- total length of hatchlings in the 1.4-2.3 mm range. Larvae of ing is performed at 5-7 d intervals. . mostgrouper species aresmall andfragileandhave smallmouths at first feeding. Yolk and oil, which nourish early larvae until Grow-out after feeding begins, tend to be exhausted quickly, generally In the Indo-Pacific and Middle Eastern regions, several spe­ within 2-5 days (Kohno et al. 1994, Tucker 1998). Typically, the cies of grouper arefanned in cages, ponds andtanks,but mostly larval period is long (often about 50 days, range 35-70 days), andgroupers tend to require live food longer than most marine fish that have been reared. They have been stocked at 0.3-60 eggs or larvae/I, usually 5-20. Careful ad- ministration of thyroid hormonescould be usedtoincrease health andsurvival of grou­ Fig. 21 (below). Minimum stocking­ perlarvaeandto acceleratetransformation. sized Goliath grouper in Fiorida (55 Commercial-scaleAsian hatcheries have mm, 2 g). (Photo by Lewis BUllock, Fiorida Fish and Wildlite raised large batches of juveniles, with sur­ Conservation Commission) vival as high as 34 percentfrom hatchlings. The best survival has occurred in larger tanks (60-500 m') under partial sunlight. Species with small mouths need small ro­ tifers, trochophores (oyster or clam larvae), Fig. 22 (above). Stocking-sized copepods, or other zooplankters at first Malabar grouper (3 g) in Taiwan. feeding. Larvae of some species, like (Photo by John Tucker) Nassaugrouper, seem to be especially sen­ sitive to noises, such as bumping of their tanks, which induces rapid, frantic swim­ ming. Providingthecorrectamountof tur­ bulence in larval tanks is critical. With too little turbulence, the water stratifies (maybe ther­ mally), and zooplankton and fish can aggre­ gate dangerously, possibly with oxygen deple­ tion, frequent collisions or feeding difficulty, because they are attracted to bright areas of the tank. With too much turbulence, the fish Fig. 23 (ielt). Stocking­ are battered. Stressed (e.g., by fright, strong sized Nassau grouper (3 g) in Fiorida. (Photo by John current, toxins,pathogens ormalnourishment) Tucker)

38 SEPTEMBER 2003 they are raised from wild juveniles thoughtheirtags hadbeen lost, two andarefed trashfish. They sometimes groupers seen at 297 days and one are fed small tilapia and sometimes at 16 months probably were re­ are polycultured with them. Typical leased fish. market size is 500-1,000 g, which can be reached in 6-8 months of growout. Nutrition The usual minimum size to begin Foods for Larvae grnwont, 75-100 mm, about 10 g (age 3-4 months), can be obtained in nurs­ Grouperlarvae usuallyareraised ery tanks, cages, or ponds. Initially, ingreenwater,mostly with thephy­ they are stocked up to 60 fish/m-' toplankton Nannochl orop sis, lkg/m in cages. Density usually Tetrasetmis and/or Chlorella spp. (c ') Fig. 24. Gag (Mycteroperca microlepis) in Fiorida (32 stocked at 10-500 cells/pl during 0­ is reduced somewhat as they grow. mm, 1 g). (Photo by Lewis Bullock, Fiorida Fish and In the Philippines, 500- to 10,000­ Wildiife Conservation Commission) 3 days after hatchinging to 12-40 m? rectangular earthen or concrete days after hatchinging. At first feed- ponds with depths of 1-2 m and level ing, most species can easily eat bottoms arethe preferred types for growout. Double watergates, small rotifers, butoyster, clam, or mussel eggs and larvae some­ aerationdevices, andemergency waterpumpsshould be present. times are used as a supplement. Growth and survival tend to be TYpically, juveniles are stocked at 5,000/ha and grown from 50­ better if copepods or mixed zooplankton are included in the diet, 100 mm to 400-1000 g. Foods include trash fish and sometimes but care must be taken to avoid introduction of pathogens or tilapia living in the ponds. predators. Certain ciliates (with widths of about 20-80 1J111)could In Taiwan, undersized (25-mm) juveniles are raised in 100­ be added to improve survival during the first few days of feed­ m2 nurseryponds or tanks to about 60 mm before being stocked ing, butsome types are not nutritious.Cladocerans (water fleas) in 2,000 m- growoutponds. Sometimes cages (1.2 ' 0.8' 0.8 m), are sometimes used for early to mid-stage larvae. Artemia en­ with a maximum of 2,000 fish each, are used in the nursery ponds. riched with essential fatty acids can be a staple food beginning Intensive pond farms have stocked juveniles at 60,000-80,000/ at 10-30 days after hatchinging, but their abundance should be ha and harvested 80 percent of them, for a production density as controlled.to minimize gorging and incomplete digestion by the high as 30,000-40,000 kg/ha (usually 10,000-30,000 tons) with larvae. It lS best to delay feeding of Anemia as long as other aerationand 20 percent waterexchange/day. Those groupersare foods are sufficient (until 20 days after hatchinging or later). fed mostly trash fish and can grow from 46 mm (2-3 months Mysid shrimpsometimes are used for late larvaeand earlyjuve­ old) to 600 g in 12 months and can reach 2 kg in 19 months. niles. Unless the wateris very well mixed, the live foods are not distributed evenly in the tank and average prey density is only Orangespotted groupers can grow from 60 mm TL to 400-800 o0 after 8-10 months in cages or 10-14 months in ponds (Rimmer of theoretical value. What matters is that the fish can find and 1998). King groupers can grow from 75 mm to 2.4 kg in I yr catch nutritious prey with a minimum of effort, maximize their and 15 kg in 2 yr. intakeof nutrients aridgrow fast. Depending on age and number Improvement of early growth rates (e.g., with better tempera­ of larvae, an average density of 5-20 rotiferslml seems appro­ ture control and earlier weaning) will allow production of 600 g priate if larvae are feeding well enough to prevent the rotifers Nassau groupers within 12 months, I kg gronpers within 18 from becoming more numerous and crowding the fish. Anemia months and 2 kg groupers within 24 months. usually are stocked at about 1-2/ml when first given to the lar­ vae, but as many as 6/ml can be used if the fish eat them within Stock Enhancement 12 hours, before their nutritional quality deteriorates. Microfeeds have been tried as a supplement during the first In isolated locations where groupers have been severely de­ week but probably are not digested much until at least 2-4 weeks. pleted, it might be possible to replenish spawning stocks with Weaning from live food to dry crumbles or small pellets can be rearedfish. In an experimental study, 27 Nassau grouperraised completed just before or duringtransformation, which occurs at in tanks in Florida (309-367 mm TL, 579-1,098 g, mean 909 g) 35-70 days afterhatchinging, depending on species. Minced sea­ were released and monitored by a diving team on an open ocean food, such as muscle of fish, shrimp or scallop often is used as reef with depths of 1-15 m at St. Thomas, U.S. Virgin Islands an appetizer or transitional food. (Roberts et ai. 1995). For three months before release, live and Taiwanese hatcheries use a range of systems to raise grouper frozen foods were added to their diet. Although they had been raised on pellets, the groupers ate live goldfish and crabs within larvae, and survival of seven percent to four weeks (25-30 mm) seconds after they were placed on the bottom of their raceway. is considered good (Rimmer 1998). Indoor systems include fi­ After release, they exhibited behavior until then expected only herglass or concrete tanks holding up to 100 rn' where larvae are reared in green (50,000-500,000 cells/ml) or clear water with from wild groupers. Within I hour after release from a holdinzo cage, all the groupers had gobies and shrimp remove ectopara- oyster trochophores (about 4-6 days after hatching), small roti­ sites obtained while theywere in thecage. Within 2 days, some fers (beginning abour-l days afterhatching), andAnemia andlor were seen hunting alongside a moray eel or octopus. It was sur­ adult copepods (beginning 16-22 days after hatching). Outdoor prising that these behaviors known for wild groupers were in­ systems include concrete or earthen ponds of 200-5,000 m2 nate and did not have to be learned by the hatchery fish. AI- (Continued on page 57)

WORLD AQUACULTURE 39 trernes, turbidity and pollutants than those A possible alternative approach to pre­ of offshore (especially reef, species). vent larvae from sticking to the surface is Most groupers that have been reared to lubricate the water surface with oil ex­ are warmwater fish that spawn and grow tracted from omega yeast for the first few best in the range 24-30'C; most can tol­ days after hatching, but the oil has to be erate a range of 15"C to at least 35"C. Eggs removed hefore larvae hegin gas bladder (Continued[rom page 39) of groupers that spawn at sea will require inflation (Yamaoka et 01.2000). (sometimes I hal, which are Filledthrough a salinity of ahout 30 ppt or higher for Usually, a moderate growth of phy­ a fine-mesh sock filter 1-2 days before them to float, hut slightly lower salinity toplankton is maintained in rearing water stocking eggs to limit the size of ZQOP­ can he tolerated even though the eggs for grouper larvae (greenwater culture). lankters. Stocking rate is 600-1 ,500 eggs! 2 sink. Salinity tolerance usually increases Besides heing food for the zooplanktonic m . Larvae are held in floating bags for with age. Oceanic species are healthiest prey ofthe fish, the algae also can remove the first 2 days offeeding (ahout 4-6 days at close to seawater salinity (35 ppt), but ammonia, generate oxygen and keep pH after hatching) to keep the trochophores some estuarine species can survive at less high, release anti-bacterial or growth-pro­ concentrated. Rotifers, copepods and than 10 ppt. Some natural light is good moting substances, promote growth of other zooplankters raised in separate for all stages. Continuous natural and ar­ beneficial bacteria and stimulate behav­ ponds of 0.05-0.1 ha are pumped directly tificial light at 1,000-3,000 lux should be ior, feeding or digestion. However, algae into the fish ponds or collected in nets and suitable for larval rearing, but higher in­ decomposition products can contribute to transferred. tensities have been used. For most formation of a sticky surface film. Feeds warm water marine fish to be healthy, dis­ In SoutheastAsia, groupers have been solved oxygen should be at least 5 mgIJ Health fed mainly trash fish supplemented with and, preferably, near saturation. Safe lim­ Good management of the microbial vitamins and minerals, secondarily moist its for ammonia, nitrite and nitrate are environment can protect larvae from or semi-moist pellets, and rarely high pro­ only approximately known. Ammonia pathogens and eliminate the need for an­ tein dry pellets. Nursery foods include should he kept near zero (El l-/g!1[ppb] tibiotics and other drugs. As a major man­ larger zooplankton, chopped fish or unionized ammonia nitrogen for larvae, agement component, we routinely inocu­ shrimp and compound feeds. About 70 £5 ug/l for adults); 10 Ilgl1 unionized late larval rearing systems with probiotic percent of Taiwanese farmers were using ammonia can be toxic to larvae, and ju­ (beneficial) bacteria isolated tram healthy compound (mainly moist) feeds in 1998 veniles and adults are only slightly more fish raised in our hatchery (Kennedy et (Rimmer 1998). tolerant. Likely limits for nitrite nitrogen al. 1998). Without this seeding, the hac­ A suitable starter feed for groupers are 0.1 mgl1 (ppm) for larvae and I mg!l teria populations can vary from had to would contain 50-60 percent high qual­ for older fish, hut zero is hest. It is prob­ good. ity protein, 12-16 percent fat (halfor more ably best to keep nitrate nitrogen lower Viruses (viral nervous necrosis, golden from marine sources), £15 percent carbo­ than 20 mg!1 for young stages and 50 mg! eye disease, herpes, Lymphocystis), gram­ hydrate, <3 percent fiber and

WORLD AQUACULTURE 57 dling) combined with Inw water quality, Fillets typically sell for $15 to $20/kg mm) in the second. The culture period and signs often include darkening, hem­ wholesale and $24-33/kg retail. In east would be about 115 d shorter for 1.36 kg orrhaging, ulceration anderosion of skin central Floridaduring summer 2002, gag fish, but to take advantage of their fast (including the fins), cloudy eyes, anor­ fillets sold for up to $20/kg whnlesale and growth in this size range (<:4.0 g/d), the exia, loss of coordination and mortality. $33/kg retail. In Nassau (Bahamas), live groupers should be raised to at least 1.8 Parasitic ciliates and dinoflagellates Nassau groupers are sold for $11.00­ kg. Overall feed cost would be $0.70­ tTricliodina spp., Cryptacaryon irritans, 13.20/kg by dealers who buy directly from lAO/kg of fish (feed $0.55-1.1O/kg,over­ Amyioodinium sp.), have caused high fishing boats. In Hong Kong, live grou­ all feed conversion ratio 1.275, overall mortality of early and older juveniles. The pers (0.5-2 kg) are worth $22-44/kg protein conversion ratio 0.757). The 1.8 most commonproblemreported forwest­ wholesale, depending on species, but kg groupers would be worth at least $7­ ern North Atlantic species has been in­ prices can drop to near $13/kg (Chan IO/kg whole and at least $15-20/kg as fil­ festation of the gills, eyes and skin by 2001) when supply is high. Cesar et al. lets (wholesale). monogenean or protozoan parasites, (2000) reported that Hong Kong market A $36.3 million recirculating intensive which feed on blood, skin and mucus. prices for live groupers were $15-65/kg tank farm (including hatchery and pro­ They alsn frequently infest caged Asian in May 1999. cessing plant) in the southern U.S. that groupers, causingsmall hemorrhages and Although studies have been conducted can produce 7.8 million kg oflive marine secondarybacterial infections. on spawningandlarvalrearing of dozens warmwater fish peryear with gross sales Routine monitoringcombined withthe of serranids, grouper farming fluctuates of $50.3 million has been estimated to latest rapid detection methods will help because of the lackof sustained hatchery have $18.7 million annual operating costs preventthespreadof disease.The current production for most species andvariabil­ and $2.9 million depreciation (Tucker published treatment methods and govern­ ity in the (mostly decreasing) supply of 1999). Itemized operating costs would be: ment regulations always should be con­ wild juveniles. Inconsistent quantity and feed 33 percent (assuming $0.55/kg); sulted before treating fish. Vaccines for quality of trash fish and the lack of eco­ utilities 12 percent; labor 40 percent; certaingrouper diseases might be avail­ nomical compound feeds have also been marketing, sales and freight 10 percent; able in the near future. Many drugs still handicaps in some areas. The extended and miscellaneous 5 percent. used in certainregions are dangerous to larvalperiod and variable survival make For fish farming in the southeastern the environment, the fish and/or the con­ the effort and cost of producing grouper United States and Caribbean region, Nassau sumer. It is better to prevent disease by juveniles in hatcheries higher than for groupers, gags, black groupers and Goliath practicing good sanitation methods,such most other types of fish. Once the juve­ groupers are good candidates. In the U.S., as stocking specific-pathogen-free juve­ nile stage is reached, survival should be growout most likely will occurin offshore niles, not using raw trash fish for fnod and near 100 percent. Gond growth and feed cages or recirculating tanks. raising fish in a clean environment. conversion will makegrowouteconomi­ Traditional Asian style grouper farming Spread of diseases from shipping of in­ cal;however, water qualitymustbe main­ is not appropriate for the U.S. Inshore ar­ fected stock should be avoided. For main­ tained at a higher level than for purely eas suitable for cage culture, such as well­ tenance of good health, factors to be estuarine or coastal fish. In many areas, tlushed deep bays, are very rare in the avoided are: overstocking, underfeeding, cages have been preferred for growout, southern U.S. Collection of wild juveniles low oxygen, low water quality, handling but there has (0 be good water exchange is seasonal, unreliable and in most cases, injuries and lack of sanitation. and a minimum of 3-5 m of waterbelow unethical and illegal. The use of trash fish the cages to limit diseases and self-pollu­ for food is wasteful and could result in dis­ Economics tion. Ponds are not necessarily better. If ease transmission. It would be unwise to Nearly all species in this family large the value of the fish is high enough, re­ initiate such non-sustainable methods. enough to eat are preferred food fish. circulating tanksystems can bejustified. Sophisticated hatcheries with good Groupers usually are very easy to catch, environmental controlandverydedicated Future Prospects and in many areas, stocks have been staffs are necessary for raising groupers highly depleted by overfishing. Withone larval rearing tank, six nurs­ fromeggs. Obtaining eggs frommostspe­ Typical market sizes are 400-700 g in ery tanks, six phase-I growouttanks, and cies is relativelyeasy. However, larvae of the Philippines, 600-900 g in Singapore 24 phase-II growout tanks, it would be most are fragile, and reported survival and> Ikg in Kuwait (Baliao et af. 1998). possible to raise 54,545 kg of Nassau from eggs tojoveniles often has been only Theusualminimum marketsize forgrou­ groupers worth US$382,000-$545,000 in 0-1 percent. With a good hatchery and pers in the U.S. is 2 kg, but smaller fish 2 yr (Tucker 1999). Hatchery costs would staff, routine survival of at least 10 per­ can be sold in specialized markets, espe­ be less than $ 1.00 per weaned, 70-day­ cent is attainable. Juvenilesandadultsare cially in large cities. Recent wholesale old, 50-mm juvenile. In nursery tanks, among the hardiest of fish and their feed prices for dead groupers in the eastern those early juveniles would be raised to conversion is good. U.S. were in the range $6.15-9.37/kg de­ robust125-mmjuveniles, withpellet size Year-round egg production in environ­ pendingon species andseason. Skinless, increasing from 1.6 to 2.4 mill. During mentally controlled spawniug tanks will boneless fillet yield for groupers is about growout,thosejuveniles would be raised permit a continuoussupplyof market size 36-40 percent, at least as good as channel to 230 mm (pellets up to 4.0 mm) iu the groupers. Good management ofbroodflsh catfish, tilapia and hybrid striped bass. first phase and 450 mm (pellets up to 9.5 and the larval rearing environment, in-

58 SEPTEMBER2003 eluding the bacteria, will allow produc­ Environmental Sciences, Kalmar Epinepltelus coioides. Ichthyological tion of specific-pathogen-free juveniles, University, Kalmar, Sweden. Research 44:267~274. which greatly reduces the risk for growout Chan, P. 2001. Taiwan grouper hatchery Powell, A.B., and l.W. Tucker, Jr. 1992. Egg operations. Vaccination of groupers for production in 2000. Secretariat of the and larval development of laboratory­ major diseases, such as vibriosis, is likely Pacific Community, Live Reef Fish reared Nassau grouper, Epinephelus Information Bulletin (8):32-33. striatus (Pisces, Serrunidae). Bulletin of in the future. FAO. 2002. Aquaculture Production 2000. Marine Science 50: 171-185. Notes Food and Agriculture Organization of the Rimmer, M. 1998. Grouper and snapper United Nations, Rome, Italy. Yearbook of aquaculture in Taiwan. Austasia 1 John Tucker is Head of the Fish Biology Fishery Statistics, Vol. 9012. Aquaculture 12(1):3-7. Department, Division of Marine Science, Johannes, R.E. and N.J. Ogburn. 1998. Is Roberts, C.M., N. Quinn, Lw. Tucker, Jr. and Harbor Branch Oceanographic Institution, harvesting wild groupers for growout P.N. Woodward. 1995. Introduction of 5600 North U.S. One, Fort Pierce, Florida sustainable? Pages 30-31 In M.E. hatchery-reared Nassau groupers to a coral 34946 USA. Hatziolos, AJ. Hooten and M. Fodor, reefenvironment. North American Journal "Pera more in-depth review, see John Tucker's editors. Coral Reefs: Challenges and of Fisheries Management 15:159-164. chapter on Grouper Culture in A. M. Kelly Opportunities for Sustainable Sadovy, y. 2001. Summary of regional survey and J. Silverstein, editors. "Manual ofFish Management, Proceedings of an of fry /fingerling supply for grouper Culture", Volume Ill, to be released in Associated Event of the Fifth Annual World rnuriculture in Southeast Asia. Secretariat 2002. Bank Conference on Environmentally and of the Pacific Community, Live Reef Fish References Socially Sustainable Development, Information Bulletin (8):22-29. Washington, n.c, USA. Tucker, .l.W, Jr. 1994. Spawning by captive Baliao, D.D., M.A. de los Santos, E.M. Kennedy, S.B., lW. Tucker, Jr., CoL. Neidig, serranid fishes: a review. Journal of the Rodriguez and R.B. Ticar. 1998. Grouper G.K. Vermeer, V.R. Cooper,J.L. Jarrell and WorldAquacultureSociety 25:345-359. Culture in Brackishwater Ponds. Southeast D.G. Sennett. 1998. Bacterial management Tucker, J.W., Jr. 1998. Marine Fish Culture. Asian Fisheries Development Center, strategies for stock enhancement of Kluwer Academic Publishers, Boston, Aquaculture Extension Manual No. 24, warrnwater marine fish: a case study with Massachusetts USA. Tigbauan, Iloilo, Philippines. common snook (Centropomu s Tucker, J. W., Jr.! 999. Grouper aquaculture. Cesar, H.S.J., K.A. Warren, Y.Sadovy, P. Lnu, undecinialis). Bulletin of Marine Science Species profile. US Southern Regional S. Meijer and E. van Ierlund. 2000. Marine 62:573-588. Aquaculture Center (USDA). Publication market transformation of the live reef fish Kohne, H., R.S. Ordonio-Aguilar, A. Ohno No. 721. food trade in Southeast Asia. Pages 137­ and Y. Tuki. 1997. Why is grouper larval Yamaoka, K., T. Nanbu, M. Miyagawa, T. 157 In H.S.J. Cesar, editor. Collected rearing difficult": an approach from the Isshiki andA. Kusuka. 2000. Water surface Essays on the Economics of Coral Reefs. development of the feeding apparatus in tension-related deaths in prelarval red­ CORDIO, Department for Biology and early stage larvae of the grouper, spotted grouper. Aquaculture 189:165-176.

further confuse the reader as to the distinc­ sirable conditions or contaminants such (Continued front page 52) tion between thetwo, as: Insects, Hair, Filth, Spoilage, Eco­ would not be - unless the product was Table 4.6 "Hazard Analysis for nomic fraud and Violations of regulatory part of the 41 percent of aquacultured Breaded Shrimp," states that battering and food standards not directly related to product, in which case it might very well breading is not a critical control point safety." be a CCP. Also, if this is the point where when in fact it is a CCP, and is addressed Combining monitoring and sampling shrimp will be assessed for excessive in detail in Chapter 15 of the US Food in the same chapter is confusing in that bisulfite (an additive, and listed here un­ and Drug Administration's (FDA) Fish monitoring is routinely performed (con­ der hazards) then this indeed is a critical and Fisheries Products Hazards and Con­ tinuously if possible) under the "monitor­ control point, as sulfites are a potential trols Guidance, 3rd edition, 2001. ing" part of a CCP, whereas sampling is health hazard and not only must be used Chapter 6 discusses sampling and more often thought of as a periodic pro­ correctly so as not to exceed 100 parts per monitoring. While providing an excellent cedure used in the "verification" part of a million, but also must be included on the reference on designing sample schedules, HACCP Plan. package label. Unfortunately, sulfite use carrying out organoleptic analyses, physi­ As I stated in the introductory para­ is not considered critical further on in the cal testing and determination of filth in graph, I found several chapters in this worksheet under either Additive Treat­ shrimp this chapter again could confuse book to be excellent references. However, ment or Packing/weighing. the reader as to just what HACCP is all I would recommend that a shrimp proces­ When teaching the seafood HACCP about; that is, foud safety, not quality. I sor also consult the FDA HACCP manu­ class I never list critical limits, preventive would quote from the FDA training als referenced above before undertaking measures, monitoring procedures, correc­ manual entitled HACCP: Hazard Analy­ a hazard analysis and subsequent devel­ tive actions, records and verification for sis and Critical Control Point Training opment of a HACCP Plan for their par­ processing steps that are notcritical, as was Curriculum, 4th edition, 2001. "In ticular shrimp processing operation. done in table 4.4. Most of the comments HACCP, 'hazards' refer to conditions or -Russell Miget describing these "non-Cf'P' processing contaminants in foods that can cause ill­ Texas Marine Advisory Service steps describe quality, not safety issues and ness or injury. It does not refer to unde- Corpus Christi, Texas USA

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