Salinity can change the lipid composition of adult Chinese mitten crab after long-term salinity adaptation (original) (raw)
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Journal of Experimental Zoology Part a-Ecological Genetics and Physiology, 2003
Lipids seem to be the major energy store in crustaceans. Moreover, they are extremely important in maintaining structural and physiological integrity of cellular and sub cellular membranes. During salinity adaptation, energy-demanding mechanisms for hemolymph osmotic and ionic regulation are activated. Thus, the main goal of this work was to verify the possible involvement of lipids as an energy source in the osmotic adaptation process. The estuarine crab Chasmagnathus granulata was captured and acclimated to salt water at 20% salinity and 20 7 21C, for 30 days. After acclimation, crabs were divided into groups of ten and transferred to fresh water (0%), salt water at 40% salinity, or maintained in salt water at 20% salinity (control group), without feeding. Before and seven days after the salinity change, wet weight and lipid concentration in gills, muscle, hepatopancreas, and hemolymph were determined according to the colorimetric assay of sulphophosphovanilin. Results show that hepatopancreas lipids were not mobilized during osmotic stress regulation. Gill and muscle lipids were significantly lower in crabs subjected to hypo-osmotic stress than those subjected to the hyper-osmotic stress or maintained at the control salinity. Our results point to the occurrence of lipid mobilization and involvement of these compounds in the osmotic acclimation process in C. granulata, but with differences between tissues and the osmotic shock (hypo or hyper) considered.
Aquaculture Research, 2011
Precocious puberty is one of the major constraints to the further development of Chinese mitten crab (Eriocheir sinensis) farming industry. Although dietary phospholipids (PL) and highly unsaturated fatty acids (HUFA) supplementation have been shown to enhance the growth of larval E. sinensis in other studies, it is still unknown whether this also leads to a higher precocity rate for juvenile E. sinensis. This study was conducted to investigate the e¡ects of dietary PL and HUFA on precocity, survival, growth and hepatic lipid composition of juvenile E. sinensis. Two diets were formulated with PL [3.95% dry weight (DW)] and HUFA (0.98% DW) supplementation (diet A) and without PL and HUFA supplementation (diet B) and fed to juvenile E. sinensis. Although dietary PL and HUFA levels did not signi¢cantly a¡ect the survival and growth performance of juvenile E. sinensis, compared with crabs fed diet A, a higher precocity rate was found among juvenile E. sinensis fed diet B (P 5 0.051). A higher total lipid content, but sig-ni¢cantly lower levels of HUFA and PL (Po0.05) were found in the hepatopancreas of crabs fed diet B than in those fed diet A. Meanwhile, the precocious females had signi¢cantly lower hepatosomatic index , arachidonic acid (20:4n-6), eicosapentaenoic acid (20:5n-3) and docosahexaenoic acid (22:6n-3) contents in their hepatopancreas when compared with that of the normal immature juveniles (Po0.05). The results suggest that the occurrence of precocious puberty among farmed juvenile E. sinensis could be reduced by the inclusion of appropriate level of dietary PL and HUFA. Ã Vitamin mix: 1kg of diet contained vitamin A 10 000 IU; vitamin D 2500 IU; vitamin K 64 mg; thiamin 60 mg; ribo£avin 250 mg; pyridoxine 60 mg; a-tocopherol acetate 500 mg; L-ascorbic acid 4.5 g; calcium panthothenic 240 mg; niacin 60 mg; folic acid 12 mg; biotin 50 mg; cyanocobalamine 4 mg. wMineral mix: 1kg of diet contained Ca(H 2 PO 4 ) 2 10 g; MgSO 4 Á 7H 2 O 2.4 g; KCl 4.5 g; NaCl 2.1g; FeSO 4 Á H 2 O 155 mg; CuSO 4 Á 5H 2 O 40 mg; ZnSO 4 Á H 2 O 80 mg; MnSO 4 Á H 2 O 30 mg; KI 11.7 mg; CoCl 2 Á 6H 2 O 4.8 mg; Na 2 SeO 3 2.4 mg. Bold highlights the level di¡erence between two diets. Aquaculture Research, 2011, 42, 457^468 Dietary PL and HUFA on the precocity of juvenile Eriocheir sinensis X Wu et al. r
Frontiers in Physiology, 2018
Salinity plays a key role affecting ovarian development, osmoregulation and metabolism of female Chinese mitten crab, Eriocheir sinensis during reproductive migration. In this study, female E. sinensis after their puberty molt were subjected to four salinities of 0, 6, 12, and 18‰ for 40 days to investigate the salinity effects on their ovarian development as well as a range of important physiological parameters. Elevated salinity accelerated the ovarian development with ovigerous crabs found at salinity treatments of 12 and 18‰ despite no copulation had occurred. Meanwhile the survival rate of female crabs showed a decreasing trend with increasing salinity. Higher salinity also led to increased hemolymph Na + , K + , Ca 2+ , Cl − , and Mg 2+ concentrations. The 6‰ treatment had the highest contents of hemolymph total and major free amino acids while the Na + /K +-ATPase activity in the posterior gills was the lowest among treatments. Total n-3 polyunsaturated fatty acids (n-3PUFA) and n-3/n-6 PUFA ratio in the anterior gills showed a decreasing trend with salinity while 18‰ had the highest PUFA and n-6PUFA. The n-3PUFA content and n-3/n-6 PUFA ratio of the posterior gills showed a fluctuating pattern and the highest value was detected at 0‰, while an increasing trend was found for the n-6PUFA with increasing salinity. The hemolymph glucose showed a decreasing trend with increasing salinity and the highest total cholesterol in hemolymph was detected at 12‰. The 18‰ treatment had the highest levels of hemolymph γ-glutamyltransferase, alkaline phosphatase and acid phosphatase, as well as glucose, urea and acid phosphatase in hepatopancreas while the highest hemolymph superoxide dismutase and malondialdehyde were detected at 0‰. Overall, the results showed that salinity increase from freshwater to brackish conditions led to lower metabolism, accelerated ovarian development, and the appearance of ovigerous crabs without copulation in female E. sinensis post puberty molt.
Marine and Freshwater Behaviour and Physiology, 2013
Rainbow trout (Salmogairdneri), acclimated to 5°C or 20"C, were reacclimated to water of the opposite temperature. The time course of alterations in fatty acid composition of microsomes from gills and liver was monitored over a 28-day period. Two to six days were required for maximum changes in fatty acid levels with acclimation to 20"C, whereas 10-17 days were required in the opposite direction. Fatty acids from gill microsomes had lower U/S (ratio of unsaturates to saturates) and UI (unsaturation index) and a shorter average chain length than liver microsomes; these differences were preserved with acclimation. In both tissues the U/S, UI, and chain length increased with cold adaptation and decreased with warm adaptation. In gill microsomes, changes in UI and U/S were due primarily to altered levels of saturated fatty acids and 20:4 (n-6) and 205 (11-31. The latter two acids, products of the A5 desaturation step in PUFA biosynthesis, also contributed to the changes in unsaturation in liver microsomes, but to a lesser extent. In liver, adjustments in unsaturation indexes were initially mediated by large but transient changes in levels of saturates and monoenes, whereas changes in polyunsaturated fatty acids of the n-6 and n-3 families were delayed 3-6 days. Thus, changes in fatty acid composition that accompany acclimation to a different temperature can be resolved into those metabolic reactions (e.g., A5 desaturation) that are of major importance and, in the liver, into temporally more than one mechanism (e.g., altering monoenes and PUFA at different times).
General and Comparative Endocrinology, 2019
Estradiol is an important sex steroid hormone that involved in regulation of animal lipid metabolism. However, the effect of estradiol on lipid metabolism in swimming crab (Portunus trituberculatus) is unclear. The present study investigated the effect of four concentrations of exogenous estradiol (0, 0.01, 0.1 and 1 μg g −1 crab weight) on the expression levels of lipid metabolism-related genes, lipid composition and histology of hepatopancreas in the P. trituberculatus. The results showed that the mRNA levels of carnitine palmitoyltransferase I and II (CPT-I and CPT-II) increased significantly at the low concentrations (0.01 μg g −1 and 0.1 μg g −1), while decreased significantly in the highest concentration (1 μg g −1). The mRNA levels of acyl-CoA oxidase (ACOX), fatty acid transport protein (FATP), fatty acid-binding protein (FABP), diacylglycerol acyltransferase 1 (DGAT1) and acetyl-CoA carboxylase (ACC) were significantly down-regulated. The transcripts of fatty acid synthase (FAS) and fatty acyl desaturase (FAD) decreased significantly only in 1 μg g −1 treatment. All estradiol treatments (0.01, 0.1 and 1 μg g −1) had significantly higher percentages of 20:4n6, 20:5n3 and 22:6n3, but lower percentages of total monounsaturated fatty acids and polar lipids than the control treatment (0 μg g −1). Histological observations indicated the size of B cell became larger under estradiol treatment. The results indicated that estradiol promoted lipid catabolism in the hepatopancreas of P. trituberculatus.
The significance of lipids at early stages of marine fish: a review
Aquaculture, 1997
The present work reviews the significance of lipids at different early stages of marine fish larvae. Lipids in broodstock nutrition are considered to be important for the quality of the larvae. Lipids affect the spawning and the egg quality of many fish species and a deficiency in (n-3) highly unsaturated fatty acids (HUFA) in broodstock negatively affects fecundity, fertilization rate and hatching rate of the species studied. Lipids as a source of energy at the embryonic and larval stage (before first-feeding) are evaluated in relation to other sources of energy such as protein and carbohydrates. After hatching and prior to first-feeding, some marine species show a preference in catabolizing phosphatidylcholine, whereas phosphatidylethanolamine tends to be synthesized. The effect of long-term (LT) and short-term (ST) enrichment techniques on the lipid composition of rotifers has been documented using various marine oils/emulsions. The quantitative and qualitative lipid class and fatty acid composition of diets influenced the lipid and fatty acid composition of both LT-or ST-enriched rotifers. The nutritional improvement of Artemia is also important and may follow the general methods used for rotifers. The functions of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) during early stages of marine fish larvae are apparently different. High amounts of EPA in relation to DHA may create an imbalance in the structural composition of the phospholipids, which could affect the normal growth and the quality of the larvae. Turbot larvae tended to exhibit lower pigmentation success with lower DHA:EPA ratio in the total lipid fraction of the larvae, especially when the absolute amounts of EPA were high compared to those of DHA (in the total lipid and phospholipid fraction of the larvae). Considerable research is
Aquaculture, 1999
In a previous study feeding larval gilthead seabream on microdiets, an improved growth rate Ž . was observed when dietary n y 3 HUFA n y 3 highly unsaturated fatty acids were contained in the polar lipid fraction. A beneficial effect of dietary lecithin on n y 3 HUFA incorporation to the larval polar lipids was also observed. To confirm those results and in order to obtain additional information on larval gut and liver histological structure, 11-day-old larvae were fed 4 microdiets differing in lipid composition. In diets N X and NL X , the main sources of n y 3 HUFA were neutral lipids, and polar lipids in diets P X and PL X . Three lecithin levels were tested, being the highest in diet NL X and the lowest in diet P X . The total n y 3 HUFA level in diets N X and NL X was enough to meet the essential fatty acid requirement of larval gilthead seabream obtained in a previous study with a triacylglyceride based diet, while diets P X and PL X had a total n y 3 HUFA level lower than the minimum determined. A reduction in the larval essential fatty acid requirement to 1.5% d.w. was obtained by feeding dietary n y 3 HUFA present in the polar lipid fraction. Feeding larvae with microdiets with low polar lipid levels produced an accumulation of lipid droplets in the enterocytes and a high number of lipid vacuoles in the hepatocytes producing nuclear migration ) Corresponding author. Dpto. Fisiologıa, 0044-8486r99r$ -see front matter q 1999 Elsevier Science B.V. All rights reserved.
Lipid Profile in the Y-organ of Fresh Water Crab Barytelphusa Guerini
Crustaceans are important constituents of aquatic ecosystems and used as food throughout the world. They are used as bio monitors and bio indicators. The Y-organs of crustaceans are classical non-neural endocrine glands. They are paired and lobulated structures and are located ventrolaterally to the eye sockets. The Y-organs of crustaceans secrete ecdysteroids (moulting homone) which play a crucial role in the moulting and growth of crustaceans. Lipids are a major source of energy in marine invertebrates are involved in several essential processes for their growth, molting and reproduction. The lipid is mobilized from the hepatopancreas to meet the energy demands of all those processes resulting in ecdysis .