FAU Institutional Repository http://purl.fcla.edu/fau/fauir This paper was submitted by the faculty of FAU’s Harbor Branch Oceanographic Institute. Notice: ©1994 John Wiley & Sons, Inc. This manuscript is an author version with the final publication available at http://www.wiley.com/WileyCDA/ and may be cited as: Tucker, J. W., Jr. (1994). Spawning by captive serranid fishes: a review. Journal of the World Aquaculture Society, 25(3), 345‐ 359. doi:10.1111/j.1749‐7345.1994.tb00218.x JOURNAL OF THE Vol. 25, No.3 WORLD AQUACULTURE SOCIETY September, 1994 Spawning by Captive Serranid Fishes: A Review JOHN W. TUCKER, JR. Harbor Branch Oceanographic Institution. 5600 North U.S. Highway 1. Fort Pierce. Florida 34946 USA Abstract The current available information on spawning by serranid fishes in captivity is reviewed. Much work has been done on members of thefamily Serranidae becauseof their value as food or ornamental fish. At least 31 species have been induced to ovulate with honnones, and at least 23 species have spawned voluntarily (without chemical treatment) in captivity. Typically, a serranid female with fully-yolked oocytes will ovulate within 24-72 h (usually 36-50 h) after the first of 1-3 injectious of 500-1,000 IU human chorionic gonadotropin/kg body weight. Similar results have been obtained for several species given 1-3 injections of 10-50 Ilg luteinizing hormone-releasing hormone analogi kg body weight. Voluntary spawning has occurred mostly with well-fed uncrowded fish during the natural spawning season under conditions of ambient temperature and partial or total natural light. The necessary temperature range for spawning varies among species, and daylength seems to be a less important stimulus than temperature for serranids. Many species of grouper, sea bass, and captivity. Because common names vary, coral trout (family Serranidae) are highly scientific names are used in the text, and valued for food , and several small serranid both scientific and common names are giv­ species are highly rated as ornamentals. en in the tables. Nomenclature is as current Therefore, much work has gone into spawn­ as possible. Epinephelus salmoides and E. ing and culturing members of this family. salmonoides are synonymous with E. mal­ Except for fragility of many species as lar­ abaricus; E. suillus is synonymous with E. vae, culture characteristics ofserranids gen­ coioides (Randall 1987; Randall et aI. 1990). erally are favorable. For example, at 500 g, the Nassau grouper Epinephelus striatus had Induced Ovulation a feed conversion ratio of 1.1, and it is ca­ At least 31 serranid species have been pable ofreaching 2 kg or more at an age of induced to ovulate with hormones (Table 2 yr (Tucker and Woodward, in press). 1). When ovarian biopsies were taken from Human chorionic gonadotropin (HCG) females that eventually ovulated, oocyte di­ and luteinizing hormone-releasing hor­ ameters usually were in the range 400-500 mone analog (LHRHa) are practical agents ~m or larger. Reported minimum diameters for inducing ovulation in many species of were 400 ~m for three Paralabrax spp. (Oda freshwater and marine fish (Lam 1982; Crim et al., in press), 400 ~m for Epinephelus et aI. 1987; Marte 1990; Zohar 1989). HCG malabaricus (Kungvankij et al. 1986), 400­ dosages range from 100 to 40,000 IU/kg 425 ~m for Centropristis striata (Roberts et body weight, probably depending on how al. 1976; Tucker 1984), 482 ~m for E. fus­ well HCG mimics endogenous gonadotro­ coguttatus (Kohno et al. 1990), 500 ~m for pin. LHRHa, by injection or implantation, E . fario (Yeh et al. 1987), 500 ~m for E. is effective in stimulating release ofendog­ tauvina (Chen 1979), and 500 ~m for E. enous gonadotropin in some species that are fasciatus (Kitajima et al. 1991), but only 250 resistant to HCG. It is less likely than HCG ~m for E. akaara (Tseng and Ho 1988). to cause an immune response after pro­ Most success probably has occurred with longed or repeated treatment. fish initially having oocytes in the range from This paper summarizes current infor­ fully-yolked (:::::tertiary yolk globule stage) mation on spawning by serranid fishes in to early hydration. Doses were in the range «:l Co pyright by the World Aquaculture Society 1994 345 346 TUCKER 10D-3,000 IU HCG/kg body weight, with tion 1992). Typically, when groupers are in­ typical doses of SOD-I,000 IU/kg. Usually, jected with HCG, one large release ofviable two injections were required and ovulation eggs occurs (personal observation). Eggs ob­ occurred within 36-S0 h, depending mainly tained later usually are not viable unless the on species, initial oocyte stage, and tem­ fish go through long-term recycling (i.e., perature. Species that ovulate within 36 h weeks to months). after an injection might need only one in­ Females ofmany groupers that aggregate jection. This is the case in other families on coral reefs to spawn are highly synchro­ such as Centropomidae (common snook, nized in oocyte maturation. Some, like E. Centropomus undecimalis, Chapman 1982), striatus, spawn mainly from near the full to Percichthyidae (striped bass, Morone saxa­ the last quarter moon at prominent sections tilis, Rees and Harrell 1990), and Sciaenidae ofthe reef(Tucker et al. 1993). Others, like (spotted seatrout, Cynoscion nebulosus, E.fuscoguttatusand Plectropomus areolatus Colura 1974). Ifovulation normally occurs at Palau, spawn mainly near the new moon later than 36 h after the first of two injec­ at tidal channels of the reef (Tucker and tions but oocyte stage is such that ovulation FitzGerald 1994). Another category in­ will occur within 36 h, one injection could cludes those species that are not synchro­ be enough. An overdose of HCG or a su­ nized and have more protracted spawning perfluous injectionjust before ovulation oc­ seasons. An example is the temperate to curs might cause overhydration, possibly subtropical Mycteroperca microlepis. The resulting in reduction of egg quality, abor­ author has collected and dissected as many tion, or loss of the female (personal obser­ as 10 female specimens at a time near the vation). For serranids, HCG usually meets peak ofspawning. Condition ofovaries from at least four of the five requirements set a single site on the same day ranged from forth by Lin and Peter (in press) for effective thin undeveloped ribbons to massive organs hormone-induced spawning. Typically, 1) containing millions ofhydrated oocytes, as ovulation rate is high; 2) ovulation is nearly well as all intermediate stages. Induced complete; 3) time to ovulation is short; and spawning attempts with species that ripen 4) eggs are fertile and viable. Possible S) simultaneously should have a high success alteration of the spawning cycle (and pos­ rate if the fish are caught at the right time. sible immune reactions) is not important Relatively few broodfish are needed. On the with fish that are caught, held for a few days, otherhand, the window for obtaining spawns spawned, and released. This is particularly is narrow, and hindrances such as bad true because, in many cases, long-term cap­ weather can jeopardize culture programs. tive serranid broodstock will spawn vol­ Species that do not ripen simultaneously untarily, without chemical treatment. In rel­ usually are available for longer periods, and atively few studies with serranids, fish timing is not as critical. However, more pituitary or pregnant mare serum was used broodfish are required to ensure that some in combination with HCG, or LHRHa was females are at the right stage, and biopsies used by itself (Table 1). LHRHa was effec­ are more important to identify those indi­ tive for E . aeneus, E . malabaricus, E. poly­ viduals. phekadion, Plectropomus leopardus, and Males of certain species can be difficult three species of Paralabrax. One to three to collect in some locations (e.g., M . micro­ injections of ID-SO JIg LHRHalkg body lepis off eastern Florida, personal observa­ weight were used . P. leopardus ovulated vi­ tion). A possible solution is to cryopreserve able eggs for three consecutive nights after sperm when ripe males are available and one injection ofLHRHa; however, number store it until eggs are obtained (Chao et al. ofeggs and viability decreased after the first 1992). night (R.N. Garrett, personal communica- Because the time between ovulation and SPAWNING BY SERRANIDS 347 overripening of eggs can be as short as 1-2 Taking of biopsies also should be mini­ h, females must be observed carefully for mized because they are especially stressful signs ofoocyte hydration and ovulation. Es­ to groupers and sometimes cause infection peciall y in groupers, hydration often is in­ and reduce egg viability. In the groupers I dicated by noticeable swelling of the ab­ have worked with, the oviducts do not open domen and ovulation by protrusion of the to the outside until after ovulation, and tak­ egg mass through the genital opening (per­ ing biopsies earlier injures the fish. If stage sonal observation). The female does not of ovarian development can be predicted swim smoothly, could rest on the bottom with reasonable certainty (e.g., if some of more often, and might turn pale, dark, or the fish caught at the same time are to be bicolored. Eggs are released when the pro­ used for food , from internal condition of truding membranes are broken by abdom­ those dissected), I prefer not to biopsy. For inal contractions of the female or manipu­ other species, such as C. striata. biopsies are lation by the culturist. During the beginning not as intrusive and are better tolerated (per­ of ovulation, a small number of clear (or sonal observation). If gently passed through nearly clear) oocytes sometimes can be ob­ the oviduct into the mass ofoocytes, a short tained by biopsy or forceful stripping; these length of surgical polyethylene tubing with premature oocytes often have multiple oil inside diameter slightly larger than ovulated globules.