COBIA (Rachycentron canadum)

(L-methionine, L-proline, betain hydrochloride) as feeding stimulants were added to soy-proteinreplacement diets to find the best substitute level for juvenile cobia. The results showed the survivalrate still maintain at 100% when the fish fed with diets of soy-protein replaced at levels of 20%,60% and 80% for 3 weeks period. The highest feed intake rate was 6.2% when fish fed with diet ofsoy-protein replaced level at 0% and the lowest feed intake rate was 1.8% when fish fed with diet ofsoy-protein replaced level at 100%. However, the best weight gain and feed conversion ratio (FCR)occurred at soy-protein replaced level at 20%. They were 263% and 0.88, respectively.The resultssuggested that using amino acids as feeding stimulants added to soy-protein based diet at level of20% could get the best feed intake, survival, weight gain and FCR results.212. Bowzer, J. & Trushenski, J. (2015). Growth performance of hybrid striped bass, rainbow trout,and cobia utilizing Asian carp meal-based aquafeeds. North American Journal of Aquaculture, 77(1), 59-67.Fish meal sparing is more difficult for nutritionally demanding carnivorous fishes, but economicconsiderations and the limited supply of fish meal continue to incentivize investigations ofalternative protein sources for aquafeeds. A promising alternative to traditional, marine-origin fishmeal is fish meal derived from undesirable freshwater species, such as the invasive Asian carpHypophthalmichthys spp. To assess the relative value of such ingredients, we evaluated growthperformance of juvenile hybrid Striped Bass (White Bass Morone chrysops × Striped Bass M.saxatilis; initial weight, 21.9 ± 0.2 g [mean ± SE]), Rainbow Trout Oncorhynchus mykiss (15.1 ±0.2 g), and Cobia Rachycentron canadum (57.2 ± 0.5 g) reared for 8 weeks on practical dietscontaining different levels of menhaden fish meal (MFM), Asian carp meal (CFM), or a 50:50blend of these ingredients such that 0, 20, 40, or 60% of the estimated digestible protein contentwas derived from fish meal. Growth performance was generally consistent across taxa, and weightgain tended to increase with fish meal inclusion, regardless of its origin. However, Cobia didperform better on CFM-based diets, suggesting that MFM or CFM can yield improved performancefor some taxa or life stages, but these differences are likely to be marginal in most circumstances.We conclude CFM is a suitable and perhaps lower-cost alternative to MFM in feeds for carnivorousfishes.213. Chang, C.F., Yang, J.H., Chou, R.L., Her, B.Y., Chang, S.L., Hsu, C.H., & Chen, T.I. (2008).Effects of dietary β-1,3-1,6-glucan on non-specific immune response of cobia (Rachycentroncanadum). Journal of Taiwan Fisheries Research, 16(1), 87-95.The present study was conducted to investigate the effects of dietary β-1,3-1,6-glucan (BG) fromSchizophyllum commune on the innate immune response in cobia (Rachycentron canadum). Cobia(50-80 g) were fed a basal diet and supplemented with either 0 (control group) or 0.5% BG (glucangroup) for 60 days. The superoxide anion (O 2 - ), superoxide dismutase (SOD) concentration andlysozyme activity were analyzed at days 0, 1, 3, 6, 12, 20, 30, 40, 50 and 60. The results showedthat the concentration of O 2 - and SOD and activity of lyszoyme in cobia at BG group was higherthan those of the control group. They attained the highest levels at day 12, 20 and 24 after feeding,respectively. However, the concentration of O 2 - on day 30, SOD on day 40 and activity of lysozymeon day 40 of the fish at BG group, dropped back to the same levels as the control group. The resultsin this study showed that oral administration of 0.5% BG for 6 days enhanced immunity of thecobia, but prolonged use of BG would not increase the immunity of the cobia. Care therefore mustbe taken to maximize its effectiveness with suitable period.214. Chi, S., Tan, B., Dong, X., Yang, Q., Liu, H., Xu, Y. & Huang, H. (2011). Effect ofsupplementation microcapsule or crystalline methionine in diets on related enzyme activity of cobia(Rachycentron canadum). Journal of Fishery Sciences of China/Zhongguo Shuichan Kexue, 18(1),110-118.The present study was conducted to compare the effect of microcapsule methionine or crystallinemethionine in low-fishmeal diets on protein metabolism and digestive enzyme activities in cobia(Rachycentron canadum). Seven iso-nitrogen and iso-lipid diets, including fishmeal (positivecontrol), low-fishmeal (negative control) and five types of methionine supplementation ofcrystalline L-methionine (MET), hydroxyl-methionine calcium (MHA), cellulose-acetate-phthalatecoated methionine (CAP), resin coated methionine (RES) and tri-palmitin-polyvinyl alcohol coatedmethionine (TPA), respectively were prepared to investigate utilization of coated and crystallinemethionine in intestine of juvenile cobia. Each treatment was randomly assigned to triplicate groupsof 20 fish with initial weight of (5.40 ± 0.07) g per aquarium. Fish were maintained in flow-throughaquaria for eight weeks at water temperature ranged from 29 °C to 31 °C. The results showed that64