COBIA (Rachycentron canadum)

energy (FAE e , %) all increased first and then decreased, but the variation of feed absorptionefficiency was small, with ranges of 89.59-91.08%, 92.91-94.71%, 93.92-95.32%, respectively.Specific growth rate in wet weight (SGR w , %/day), dry weight (SGR d , %/day), protein (SGR p ,%/day) and energy (SGR e , %/day) showed a domed curve relative to temperature (T, °C), describedas quadratic equations: SGR sub w = -0.068T 2 + 3.878T – 50.53, SGR d = -0.079T 2 + 4.536T – 59.64,SGR p = -0.084T 2 + 4.783T – 63.08 and SGR e = -0.082T 2 + 4.654T – 60.99, and SGR w , SGR d , SGR pand SGR e maximized at 28.5 °C, 28.6 °C, 28.4 °C, 28.5 °C, respectively, as calculated from theregression equations. The relationships between feed conversion efficiency in wet weight (FCE w ,%), dry weight (FCE d , %), protein (FCE p , %), energy (FCE e , %) and temperature (T, °C) also tookon a domed curve described as quadratic equations: FCE w = -0.726T 2 + 39.71T – 473.8, FCE d = -0.276T 2 + 15.31T – 190.6, FCE p = -0.397T 2 + 22.05T – 277.9 and FCEe = -0.350T 2 + 19.39T –239.9, and FCE w , FCE d , FCE p and FCE e maximized at 27.4 °C, 27.8 °C, 27.7 °C and 27.7 °C,respectively, as calculated from the regression equations. Energy budget of juvenile cobia fedsatiation was 100C = 5F + 67(U+R) + 28G at water temperature 27 °C and 100C = 5F + 70(U+R) +25G at water temperature 31 °C, where C is food energy, F is faeces energy, (U+R) is excretionenergy and metabolism energy, and G is growth energy.61. Trushenski, J., Schwarz, M.H., Takeuchi, R., Delbos, B. & Sampaio, L.A. (2010). Physiologicalresponses of cobia Rachycentron canadum following exposure to low water and air exposure stresschallenges. Aquaculture, 307(1-2), 173-177.Prevention is the most viable disease management strategy in aquaculture, and prevention isprimarily driven by strategies to avoid or minimize the effects of stress. Unfortunately, there is littleinformation available regarding the stress physiology of emerging aquaculture species orappropriate experimental stressing protocols for these fishes, and thus very little context in which toevaluate mitigation strategies. Accordingly, the stress response of cobia was evaluated followingexposure to 2 experimental stressors: low water and air exposure. Juveniles were exposed to air for1min (AIR EXPOSURE), held for 15min in water lowered to the fish's lateral midline (LOWWATER), or unchallenged (CONTROL) prior to the collection of blood samples at 0 (prechallenge),0.5, 1, 2, 6, 12, 24, 48, and 72h post-challenge. Both stressors elicited classicalhaematological changes indicative of the generalized stress response, however, the magnitude of theresponse was consistently greater in the AIR EXPOSURE group. Plasma cortisol, glucose, andlactate concentrations increased rapidly in the AIR EXPOSURE and LOW WATER groups,peaking within 1h of challenge. Cortisol returned to basal levels rapidly, whereas glucose andlactate remained elevated for a longer period of time. Regardless of the stressor used, fish recoveredwithin 12h of the challenge. The primary and secondary responses of juvenile cobia challenged withlow water and air exposure appear to respond in a similar fashion to other species exposed to theseexperimental stressors. Both low water and air exposure are suitable experimental stressors for usein cobia based on their ability to induce a classical stress response and ease of implementation.62. Valinassab, T., Ashtari, S., Sedghi, N. & Daghoghi, B. (2008). Reproductive biology ofRachycentron canadum in the Persian Gulf (Hormozgan Province waters). Iranian ScientificFisheries Journal, 17(2), 143-152.We collected 478 specimens of Cobia, Rachycentron canadum, from Hormozgan province watersduring October 2005~September 2006, and studied reproductive parameters such as spawningseason, sex ratio, maturity stages, fecundity and ova diameter. The maturity and spawning seasonwere investigated through macroscopic and microscopic (ovarians histology) observation. Studyingaverage Gonado-Somatic Index (GSI), the percent of maturity stages and ova diameter averagechanges revealed that the spawning occurred from July to the beginning of September. The totalmale to female sex ratio was 1.3:1.0 which was significantly different from the normal ratio, 1:1(P