COBIA (Rachycentron canadum)

208. Weirich, C.R., Stokes, A.D., Smith, T.I.J., Jenkins, W.E. & Denson, M.R. (2006). Outdoor tankand pond spawning of cobia, Rachycentron canadum in Coastal South Carolina. Journal of AppliedAquaculture, 18(3), 1-16.Research was conducted at the South Carolina Department of Natural Resources WaddellMariculture Center to evaluate the potential for captive reproduction of cobia, Rachycentroncanadum in outdoor tanks and ponds. In May 2001, adult cobia (3 males, 1 female, and 1 suspectedfemale) obtained from a local high salinity estuary were stocked into an outdoor tank (32,000-L)receiving ambient estuary water. Spawning occurred within 2 days after stocking. Over the courseof 3 consecutive days, a total of 3.6 million eggs were collected with roughly equal numberscollected during each 24-hour period. Mean fertilization rate was 58.1%. Hatching occurred atapproximately 24 hours after initiation of each spawning event. Mean percent hatch was 27.5%.Fish were relocated to a 0.25-ha circular pond 10 days after tank spawning activity ended. Onefemale received pelleted GnRHa before stocking. Eggs were observed 3 days after stocking and at12 days after hatching, approximately 50,000 larvae were harvested. In May and June 2002, threegroups of recently caught adult cobia, each consisting of 3 males and 1 female, were placed in oneof three outdoor tanks. Spawning occurred within 2–4 days after stocking of Tanks 1 and 2. Duringa single spawning event, a total of 2.1 million and 560,000 eggs were collected from Tanks 1 and 2,respectively. Relative batch fecundity of females stocked in Tanks 1 and 2 was estimated to be 79.2and 20.9 eggs/g, respectively. No fertile eggs were collected from Tank 2. Percent fertilization andhatch of eggs collected from Tank 1 was 3.2% and 1.5%, respectively. No spawning activity of fishstocked in Tank 3 occurred. Findings reveal that naturally conditioned recently caught adult cobiacan readily spawn soon after capture and that ponds can be utilized for reproduction of this speciesin the U.S.209. Yousif, O.M., Minh, D.V., Kumar, K.K., Abdul-Rahman, A.F. & Hung, B.V. (2011).Spawning and larviculture trials of cobia, Rachycentron canadum (Linnaeus, 1766) in the UnitedArab Emirates. World Aquaculture, 42(1), 33-36.Cobia Rachycentron canadum, the sole representative of the family Rachycentridae, is a migratorypelagic species that occurs in tropical and subtropical seas except for the eastern Pacific (Arnold etal. 2002). It is a gonochoristic species that has demonstrated the capacity for high fecundity andease of induced and natural spawning in captivity (Holt et al. 2007, Benetti et al. 2008a). They aremultiple batch spawners with a protracted spawning period (Faulk and Halt 2003, Benetti et al.2008b). The information available on the timing of gonadal maturation in different parts of theworld indicates that cobia spawn from April through September with the peak in spring and earlysummer (Kilduff et al. 2002, Faulk and Halt 2003).2.6. NUTRITION & FEEDING210. Bor-Shing L. & Chen, T.I. (2004). Feeding stimulatory effects of nucleotides and relatedcompounds on juvenile cobia (Rachycentron canadum). Journal of Taiwan Fisheries Research,12(2), 49-55.The feeding stimulative effects of nucleotides and their related compounds on juvenile cobia(Rachycentron canadum) were investigated. Among these nucleotides only inosine-5'-monophosphate (IMP), guanosine-5'-monophosphate (GMP), uridine-5'-monophosphate (UMP),and adenosine-5'-diphosphate (ADP) showed high feeding stimulative responses. In contrast,nucleosides, nitrogen bases, and ribose were not effective. The optimal concentrations of IMP,GMP, UMP, and ADP for juvenile cobia were 2.9, 8.1, 2.8, and 6.6 mmol/kg dry pellets,respectively. These effects of the nucleotides were synergistic when supplemented in pairs. Thesynergic effects disappeared when the 4 nucleotides were supplemented together.211. Bor-Shing L. & Chen, T.I. (2007). Effects of amino acids added and soy-protein replacement onthe growth of juvenile cobia (Rachycentron canadum). Journal of Taiwan Fisheries Research,15(1), 55-61.This study compared the effect of amino acids (L-methionine, L-proline, betain hydrochloride)fortified test diets containing graded levels of soy-protein for juvenile cobia. In the test of addingone amino acid to pure soy-protein diet as a feeding stimulant, the results showed that the best feedintake rates were 1.84% for L-methionine replaced at level of 1.5%, 4.57% for L-proline replaced atlevel of 1.15% and 1.35% for betain hydrochloride replaced at level of 0.14%. Fortified amino acids63