Effects of Dietary Phospholipid and Cholesterol Levels on Growth, Molting Performance, and Ovary Development in Female Juvenile Crayfish (Procambarus clarkii)

Abstract

The interaction between phospholipid (PL) and cholesterol (CH) on growth performance, molting rate, hepatopancreas fatty acid composition, and ovary development of the female red swamp crayfish (Procambarus clarkii) was investigated. Nine diets containing three PL levels (0, 20, and 60 g/kg) and three CH levels (0, 5, and 10 g/kg) were included in the study. Female crayfish (initial weight: 5.92 ± 0.03 g) were reared for 60 days. There was no significant interaction between dietary PL and CH levels ( P > 0.05 ). However, the best growth performance and ovarian development were observed in crayfish receiving the 60 g/kg PL and 10 g/kg CH diet. High PL levels promoted CH transport in the hepatopancreas, and long-chain unsaturated fatty acid (C20:4n-6, C20:5n-3, and C22:6n-3) content of the hepatopancreas increased with the addition of PL in the diet. The molting rate increased with increasing CH levels in the diet containing 60 g/kg PL. Real-time quantitative polymerase chain reaction revealed that dietary CH enhanced the molting rate by improving the ecdysone receptor genes at transcription. This study showed that crayfish fed a diet containing 10 g/kg CH and 60 g/kg PL obtained maximum growth, molting rate, and ovary development.

Effects of estradiol on fatty acid composition and tissue structure of hepatopancreas in Procambarus clarkii

“…The results are different from previous studies, which commonly found that C18:n9 (oleic acid) and C18:2n6 (linoleic acid) were the main fatty acids in the hepatopancreas of P. clarkii. 10,12,13 The hepatopancreas is the main organ for fat storage in crustaceans, and the changes in fatty acid content are closely related to the changes in fatty acid content during ovarian development. During the maturation process of ovaries, the content of certain fatty acids increases while the corresponding fatty acids decrease in the hepatopancreas (Amran et al, 2018).…”

“…5,8,9 The type and content of fatty acids in the ovary of P. clarkii undergo significant changes during its development, which will naturally be reflected in the hepatopancreas, the main organ that provides nutrition for ovarian development. 10 Previous studies found that estradiol not only existed in the hepatopancreas of P. clarkii, but was also related to ovarian development. 10 Thus, this study aimed to investigate the effect of exogenous estradiol injection on the fatty acid content and tissue structure of the hepatopancreas of P. clarkii, to provide a reference for studying the roles of estradiol in ovarian development in crustaceans.…”

“…10 Previous studies found that estradiol not only existed in the hepatopancreas of P. clarkii, but was also related to ovarian development. 10 Thus, this study aimed to investigate the effect of exogenous estradiol injection on the fatty acid content and tissue structure of the hepatopancreas of P. clarkii, to provide a reference for studying the roles of estradiol in ovarian development in crustaceans.…”

Dietary effect of soybean lecithin on the growth performance, digestive enzyme activity, blood biomarkers, and antioxidative status of striped catfish, Pangasianodon hypophthalmus

“…Lecithin contains fatty acids, phosphate, and choline, which facilitate the metabolism of carbohydrates and lipids [ 14 ]. Phospholipids are involved in the structure of cell membranes and lipoproteins, which are needed for embryonic and larval growth and the luminal emulsification of lipids components [ 15 , 16 ]. Accordingly, lecithin can facilitate the absorption of lipids and digested nutrients through the intestines of fish [ 17 , 18 ].…”