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Comprehensive knowledge of osteological development of fish not only provides means for understanding its functional development, but also allows early detection of skeletal anomalies. The present study was conducted to determine osteological development and occurrence of anomalies from the first to the 40th day after hatching ( DAH) for yellow catfish Pelteobagrus fulvidraco, a commercially important species in China. Vertebral ontogeny started with formation of anterior neural arches at 3 DAH, and completed at 6 DAH. Vertebral centra started to develop at 4 DAH and ossification in all centra was visible at 15 DAH. Caudal fin appeared at 2 DAH and ossification was visible at 26 DAH. The onset of dorsal and anal fins appeared at 4 DAH and their ossifications were visible at 20 DAH. Pectoral fins were present before first feeding and formed entirely at 9 DAH, and their ossifications were visible at 21 DAH. Pelvic fins appeared at 9 DAH, and formed completely at 21 DAH. The ossification of pelvic fins was not finished until the end of the experiment (40 DAH). 24 types of skeletal anomalies were observed. About 20% of individuals showed at least one anomaly. Haemal vertebrae anomalies occurred at the highest frequency, followed by pre-haemal, caudal vertebrae and anal fin anomalies, and caudal fin had the lowest anomalies frequency. For the first time, our study determined osteological development and anomalies incidence in larval yellow catfish, which help further investigations into rearing conditions leading to appearance of these anomalies to prevent their incidence. [ABSTRACT FROM AUTHOR]

An 8-week feeding trial was conducted to determine the effect of dietary conjugated linoleic acid ( CLA) on growth performance, muscle fatty acid profile, hepatic intermediary metabolism and antioxidant responses in genetically improved farmed Tilapia ( GIFT) strain of O reochromis niloticus (initial body weight: 42.6 ± 0.4 g, mean ± standard deviation). Three replicated groups of GIFT strain of Nile tilapia were hand-fed to satiation, twice a day, with the diets in which CLA oil, containing mainly the bioactive cis-9, trans-11 and trans-10, cis-12 isomers, was included at 0 (control), 0.5%, 1%, 1.5%, 2% and 2.5%, respectively, at the expense of fish oil to maintain the constant lipid and energy levels. Growth performance and feed utilization showed no significant differences among the treatments ( P > 0.05). The dietary inclusion of CLA modified total percentages of the main groups of fatty acids. Increasing saturated fatty acid content and reduced mono-unsaturated fatty acid contents in muscle were observed with increasing dietary CLA inclusion ( P < 0.05). Total n-3 fatty acids and total polyunsaturated fatty acids tended to decline with increasing dietary CLA levels ( P < 0.05), but n-6 fatty acids showed no significant differences among the treatments ( P > 0.05). Dietary CLA supplementation resulted in the significant increase in the trans-10, cis-12 and cis-9, trans-11 CLA isomers in muscle ( P < 0.05) and also significantly influenced several hepatic enzymatic activities, such as succinate dehydrogenase, lactate dehydrogenase, malic dehydrogenase, lipoprotein lipase and hepatic lipase activities ( P < 0.05). Reduced superoxide dismutase and glutathione peroxidase activities, and the decline in malondialdehyde levels were observed in fish fed the CLA-supplemented diets ( P < 0.05), indicating that dietary CLA supplementation showed a powerful antioxidant effect for this fish species. Our study was the first report involved in the effect of dietary CLA inclusion on hepatic intermediary metabolism and antioxidant responses in fish, which could be used as indicators of nutritional and physiological status of the fish species. [ABSTRACT FROM AUTHOR]

An 8-week experiment was conducted to examine the effect of partial replacement of fish meal (FM) by a mixture of soybean meal (SBM) and rapeseed meal (RM) in practical diets of juvenile Chinese mitten crab Eriocheir sinensis of initial body weight of 1.54±0.12 g (means±SD, n=90). Five isonitrogenous diets were formulated to contain 35% protein and 5% lipid. Soybean meal and RM mix (1:1 ratio) were included at five levels of 0 (control), 15%, 30%, 45% and 60%, replacing 0, 20%, 40%, 60% and 80% FM respectively. When FM was replaced by 15% of SBM and RM, crab showed the highest growth, feed utilization and moulting frequency (MF). Fish meal replaced by SBM and RM did not significantly influence crude protein, lipid and moisture contents of whole body crab, but ash content was the lowest for crab fed the diet with FM replaced by 15% of SBM and RM. Apparent digestibility coefficients (ADCs) of dry matter, crude protein and energy tended to decline with increasing inclusion levels of dietary SBM and RM. In general, ADCs of lipid were high (over 90%) and showed no significant differences among the treatments ( P>0.05). Based on these observations above, these results indicated that about 40% of FM can be replaced with a mixture of SBM and RM (1:1 ratio) in the diet of E. sinensis without adverse growth performance, compared with the FM-based diet. However, 20% of FM replaced by SBM and RM produced the best growth performance and feed utilization. [ABSTRACT FROM AUTHOR]