Effects of different salinities on growth performance, survival, digestive enzyme activity, immune response, and muscle fatty acid composition in juvenile American shad (Alosa sapidissima)

Abstract

The effects of salinity on survival, growth, special activity of digestive enzymes, nonspecific immune response, and muscle fatty acid composition were evaluated in the American shad (Alosa sapidissima). Juveniles of 35 days after hatching were reared at 0 (control), 7, 14, 21, and 28 ppt for 60 days. At the end of the experiment, juvenile American shad presented higher survival and specific growth rate (SGR) in salinity group (7, 14, and 21 ppt) than control group (P < 0.05). The special activity of trypsin and chymotrypsin was highest in fish reared at 21 ppt, while the highest lipase special activity was obtained in control group (P < 0.05). The special activity of alkaline phosphatase (ALP), lysozyme (LZM), superoxide dismutase (SOD), and catalase (CAT) showed significant increases in salinity group (14 and 21 ppt) compared to control group (P < 0.05). Lower muscle ash contents were detected in salinity group (14, 21, and 28 ppt) than control group (P < 0.05), while the contents of crude lipid and crude protein were significantly higher than control group (P < 0.05). The level of monounsaturated fatty acids (MUFA) exhibited a decreasing trend, while an increased level of polyunsaturated fatty acids (PUFA) was detected with the increase of salinity. Among the PUFA, the content of n-3 fatty acids in muscle tissue was found to be increasing with the increasing salinity, especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Results indicate that appropriate increase in salinity was reasonable and beneficial for juvenile American shad culture after a comprehensive consideration, especially salinity range from 14 to 21 ppt.

Comparison of the growth performance and long-chain PUFA biosynthetic ability of the genetically improved farmed tilapia (Oreochromis niloticus) reared in different salinities

“…However, the effect of environmental salinity on endogenous LC-PUFA biosynthesis in fish varies among different species. Contrary to what is observed in S. canaliculatus and P. major, the muscle EPA and DHA contents in euryhalinous Alosa sapidissima increased with an increase in salinity (22) . Similarly, seawater environment also improves the accumulation of EPA and n-3 PUFA in rainbow trout Oncorhynchus mykiss liver (23) as well as the accumulation of DHA and EPA in muscle and liver of Japanese sea bass (Lateolabrax japonicus) (24) .…”

The Effect of Salinity on the Survival and Growth of Anderson's Salamander Ambystoma andersoni Larvae

“…In addition to this prophylactic effect, which is known to be effective in other species (Leutscher 1921;Mart ınez-Palacios et al 2004), saline solutions can help to maintain water hardness, which is beneficial for the skin health of axolotls (Armstrong and Malacinski 1989). Importantly, no significant differences were found in survival or proximate analysis by the end of the trial, in contrast to studies in fish, where elevated salinity affected body composition (Barman et al 2005;Hamed et al 2016;Mapenzi and Mmochi 2016;Liu et al 2017).…”

Lipid content and fatty acid composition in female American shad,Alosa sapidissima, at different stages of ovarian development under reared conditions

“…The formation of fatty acid methyl esters (FAMEs) were prepared by transesterification with boron trifluoride (BF3) in methanol using the method described by Kitts, Huynh, Hu, and Trites (). The formation of fatty acid methyl esters was detected according to Desvilettes, Bourdier, and Breton () and Liu et al (). The formation of fatty acid methyl esters was then separated and quantified by chromatography (GS, HP6890, USA) equipped with a flame ionization detector (250°C) and a fused silica capillary column (30 m × 0.32 mm i.d, CP wax 52CB; Chrompak, London, UK).…”

“…In the early 21st century, owing to the virtual extinction of the Chinese shad, Tenualosa reevesii , the American shad was introduced into China as an alternative species. To date, many studies report the species' biology and spawning behaviour (Bilkovic, Olney, & Hershner, ; Cushman, Tarpey, Post, Ware, & Darden, ; Gao et al, ; Hong, Zhu, Chen, Pan, & Li, ; Liu et al, ; Maltais, Daigle, Colbeck, & Dodson, ). However, the importance of lipid storage, mobilization, and the changes of fatty acids in different tissues to American shad reproduction has not been reported.…”