Search

The gonadal development; edible tissue ratio; and proximate, fatty acid, and free amino acid composition were examined and compared among Eriocheir sinensis samples from four sources. The gonadosomatic index (GSI) of Heilongjiang (HLJ) crabs was significantly higher than that of the other crabs from September to October (P < 0.05). Of all the edible tissues of E. sinensis, HLJ crab had the highest linolenic acid (18:3n3, LNA) and arachidonic acid (20:4n6, ARA) contents (P < 0.05), while Qinghai (QH) crab had the highest eicosapentaenoic acid (20:5n3, EPA) content (P < 0.05). The highest docosahexaenoic acid (22:6n3, DHA) and DHA/EPA contents were observed in Shandong (SD) crabs (P < 0.05), and the highest linoleic acid (18:2n6, LA) content was found in Shanghai (SH) crabs (P < 0.05). In conclusion, E. sinensis inhabiting relatively low-temperature regions (northern China) can initiate gonadal development earlier, and the quality of E. sinensis living in paddies and lakes is better than that of crabs living in ponds., (© 2021 Institute of Food Technologists®.)

Copyright of Crustaceana is the property of Brill Academic Publishers and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

There are three major wild populations of mitten crab (Eriocheir sensu stricto), Suifenhe River (SF), Tumenjiang River (TM) and Liaohe River (LH) in northern China. However, the information on the nutritional quality of these three populations of crabs is still scarce. Thus, we investigated and compared the tissue indices, total edible yield, proximate composition, fatty acid compositions and amino acid contents of these wild crab populations. We showed that: (1) TM population had the highest meat yield among the three populations; (2) TM recorded the highest moisture and the lowest total lipid content in ovary and muscle; (3) a higher level of total n-3 poly-unsaturated fatty acids was found in TM, except for the ovary in SF; (4) the three populations had similar essential amino acids scores. In conclusion, Eriocheir s.s. from these three populations all showed a high nutritional quality suitable for humans, especially the TM, which contains more eicosapentaenoic acid and docosahexaenoic acid. Résumé: Il y a trois populations sauvages majeures du crabe Eriocheir sensu stricto, Suifenhe River (SF), Tumenjiang River (TM) et Liaohe River (LH) en Chine du Nord. Cependant, l'information sur la qualité nutritionnelle de ces trois populations est encore faible. C'est pourquoi nous avons comparé les indices de tissus, le produit comestible total, la composition immédiate, les compositions en acides gras et en acides aminés de ces populations de crabes sauvages. Nous avons montré que : (1) la population de TM avait le rendement en viande le plus élevé ; (2) la population de TM présentait le pourcentage d'humidité le plus élevé et le contenu en lipides totaux le plus bas dans l'ovaire et le muscle ; (3) un niveau plus élevé d'acides gras n-3 poly-insaturés a été trouvé dans la population de TM, excepté pour l'ovaire dans la population de SF ; (4) les trois populations avaient des taux d'acides aminés essentiels similaires. En conclusion, Eriocheir s.s. de ces trois populations ont démontré une qualité nutritionnelle élevée convenable pour les humains, en particulier celle de TM qui contient le plus d'acide eicosapentaénoïque et d'acide docosahexaénoïque. [ABSTRACT FROM AUTHOR]

Copyright of Crustaceana is the property of Brill Academic Publishers and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The Chinese mitten crab (Eriocheir sinensis) is an euryhaline crustacean, whose adults migrate downstream to estuaries for reproduction. Lipids are believed to be involved in salinity adaptation during migration. This study investigated the effects of different salinities (0, 6, 12, and 18‰) on the total lipids, neutral lipids, and polar lipids contents, and fatty acid profiles in the gonads, hepatopancreas, and muscles of adult E. sinensis after 40 days of salinity adaptation. The results showed that the males and females from 12‰ treatment had the highest contents of total lipids and neutral lipids in their hepatopancreas and total lipids in the muscles. Notably, salinity had a greater effect on the fatty acid profiles in the hepatopancreas compared to that in the gonads and muscles. The male hepatopancreas treated with 18‰ salinity had the highest percentage of total n-6 polyunsaturated fatty acid (∑n-6PUFA) in both neutral lipids and polar lipids, while the percentage of total n-3 polyunsaturated fatty acid (∑n-3PUFA) in neutral lipids and polar lipids decreased significantly with increasing salinity in males. In females, the 0‰ treatment had the highest percentages of total saturated fatty acids in neutral lipids and polar lipids in the hepatopancreas, while the highest ∑n-3PUFA and ∑n-6PUFA in neutral lipids and polar lipids were detected in the 12‰ treatment group. In conclusion, brackish water could promote the accumulations of total lipids and neutral lipids in the hepatopancreas and change the fatty acid profiles of adult E. sinensis, particularly in the hepatopancreas after long-term salinity adaptation. [ABSTRACT FROM AUTHOR]

The carnitine palmitoyltransferase (CPT) family includes CPT 1 and CPT 2 that transport long-chain fatty acids into the mitochondrial compartment for β-oxidation. In this study, three isoforms (CPT 1α, CPT 1β and CPT 2) of the CPT family were cloned from Chinese mitten crab (Eriocheir sinensis) and their complete coding sequences (CDS) were obtained. Sequence analysis revealed deduced amino acid sequences of 915, 775 and 683 amino acids, respectively. Gene expression analysis revealed a broad tissue distribution for all three isoforms, with high CPT 1α and CPT 2 mRNA levels in the hepatopancreas of males and females. In males, CPT 1β was highly expressed in gill, heart, brain ganglia and muscle, while in females, CPT 1β-mRNA levels were relatively high in muscle, hepatopancreas and ovary tissue. The effects of dietary fish oil replacement on the expression of the three CPT isoforms in the hepatopancreas during gonadal development were investigated using five experimental diets formulated with replacement of 0, 25, 50, 75 and 100% fish oil by 1:1 rapeseed oil: soybean oil. The results showed that Diets 2# and 5# yielded higher CPT 1α and CPT 2 mRNA expression in males (P < 0.05), while in females, expression of all three CPT isoforms increased then declined in the hepatopancreas with increasing dietary fish oil replacement. The observed changes in CPT gene expression varied in different isoforms and gender, suggesting the three CPT genes might play different roles in fatty acid β-oxidation in E. sinensis. [ABSTRACT FROM AUTHOR]

Melatonin has been identified in a variety of invertebrate species, but its function is not as well understood as in crustaceans. The effects ofmelatonin on hemolymph glucose levels and tissue carbohydrate metabolism in the Chinese mitten crab, Eriocheir sinensis, were fully investigated in this study. Moreover, whether the eyestalk (an important endocrine center in invertebrate species) involves in this process or not, also were clarified. Analysis revealed that eyestalk ablation, especially bilateral, caused a significant decrease in the hemolymph glucose level. Moreover, injection of melatonin induced hyperglycemia in a dose-dependent manner both in intact and ablated crabs. Based on the expression of CHH mRNA in the 10 different tissues, eyestalk, thoracic ganglion, intestinal tract and hemolymph were selected to estimate the effect of melatonin on the expression of CHH mRNA. Bilateral eyestalk ablation caused a significant increase in the expression of CHH mRNA in the thoracic ganglion, intestinal tract and hemolymph compared with the controls. In addition, injection of melatonin into intact or ablated crabs elevated the CHH mRNA level in the eyestalk, thoracic ganglion and intestinal tract tissues compared with controls. The hemolymph CHH mRNA after melatonin injection was elevated only in ablated crabs. Administration of melatonin resulted in a significant decrease in total carbohydrates and glycogen levels with an increase in phosphorylase activity levels in the hepatopancreas and muscle in intact and ablated crabs. Our findings demonstrated that melatonin can induce hyperglycemic effects in both intact and ablated crabs, suggesting that this effect is probably not mediated solely via eyestalk. [ABSTRACT FROM AUTHOR]

As a catadromous species, salinity is a key parameter that affects gonadal development of Chinese mitten crab Eriocheir sinensis during reproductive migration. It is however unclear the effects of salinity on the gonadal development of male E. sinensis as well as their physiological responses to salinity during reproductive migration. This study investigated the effects of four salinities (0 ‰, 6 ‰, 12 ‰ and 18 ‰) on gonadal development, osmoregulation and metabolism of adult male E. sinensis over a 40-day period. The results showed that elevating salinity promote gonadal development, increase hemolymph osmolality and K+ and Mg2+ concentrations (P < 0.05). The 12 ‰ salinity resulted in the highest contents of taurine and arginine in the hemolymph while the highest contents of threonine, phenylalanine, lysine, ß-alanine, tryptophan, ornithine and total free amino acids were found for 0 ‰ treatment (P < 0.05). A decreasing trend was detected for the Na+/K+-ATPase activity and its mRNA expression level in the posterior gills with salinity (P < 0.05). Total saturated fatty acids in the anterior gills decreased with increasing salinity (P < 0.05); the 0 ‰ treatment had the highest total polyunsaturated fatty acids in the posterior gills while total n-6 polyunsaturated fatty acids increased with salinity (P < 0.05). The hemolymph glucose and uric acid showed a decreasing trend as salinity while an increasing trend was found for the hemolymph triglyceride and high-density lipoprotein cholesterol (P < 0.05). The 12 ‰ treatment had the highest levels of hemolymph malonaldehyde and hepatopancreatic γ-glutamyltranspeptidase (P < 0.05). In conclusion, these results suggested that the brackish water promote gonadal development of male E. sinensis, and increase osmolality and ionic concentrations in hemolymph while reduced the activity of Na+ /K+- ATPase and its mRNA expression in the posterior gills as well as metabolism. [ABSTRACT FROM AUTHOR]

Abstract: This study was conducted to determine the optimum phospholipids: highly unsaturated fatty acids (PL/HUFA) ratio in maturation diets for female Chinese mitten crab, Eriocheir sinensis broodstock. Five isolipidtic and isonitrogenous diets were formulated to contain different amounts of pork lard, fish oil and soy lecithin with resulting PL/HUFA levels (%dry weight) of 1.4/0.3 (Diet 1), 1.6/2.5 (Diet 2), 2.3/2.0 (Diet 3), 3.8/1.5 (Diet 4) and 5.1/0.8 (Diet 5). Diet 1 lacked supplemental fish oil and soy lecithin and served as the control. Each of the five formulated diets was fed to a total of 150 female crabs for a period of 7 months. All diet treatments were triplicated with 50 crabs stocked in a pond as a replicate. After 6 months, male crabs were introduced into the ponds where females were kept, mating, spawning and egg hatching (in seawater) occurred in the following month. The nutritional value of various formulated diets was assessed based on survival, gonadosomatic index (GSI), egg production per female, fecundity (eggs/g female weight) of the females fed those diets and egg and larval (newly hatched zoea I larvae) quality. Females fed Diet 1 had the lowest GSI, egg production per female and fecundity while no significant difference were found for survival, hepatosomatic index (HSI) and the percentage of female spawned among the diet treatments (P >0.05). Although there were no significant differences in egg diameter, egg wet or dry weights among all treatments (P >0.05), the highest and the second highest proportions of essential fatty acids (EFA), i.e. 20:5n-3 (EPA), 22:6n-3 (DHA) and HUFA were found in the eggs produced by the females fed Diet 3 and Diet 2, respectively. Statistical analysis showed that EPA, DHA and HUFA in eggs produced by females fed Diet 3 were significantly higher than those from the other treatments (P< 0.05). Meanwhile, zoea I larvae from crabs fed Diet 3 had significantly larger carapace length than those from the other four treatments (P <0.05). The zoea I larvae from crabs fed Diet 2 and Diet 3 also showed generally better tolerance to starvation and osmotic shock. In conclusion, our results indicated that diet included levels of PL/HUFA around 1.6/2.5 or 2.3/2.0 (% dry weight) fed female E. sinensis broodstock supported increased fecundity and elevated level of HUFA in egg, which in turn resulted in improved overall quality of newly hatched larvae. [Copyright &y& Elsevier]

Background: The finite marine resources make it difficult for us to obtain enough fish oil (FO) used in aquatic feeds. Another sustainable ingredients should be found to substitute FO. The effects of replacing FO with vegetable oil have been studied in a variety of crustaceans, but most studies have focused on the phenotypic effects. Little is known about the mechanisms of the effects. Methods: To understand the molecular responses during the replacement of FO in Eriocheir sinensis, we investigated the effects of feeding FO or linseed oil (LO) on growth performance, digestive enzyme activity, fatty acid composition and protein expression in E. sinensis. Twenty-four juvenile crabs were fed diets containing FO or LO for 112 days. Weight, carapace length and width were recorded. Fatty acid composition of the diets and the hepatopancreas and protein expression in the hepatopancreas were analyzed. Results: Growth performance and molting interval were unchanged by diet. Crabs fed FO and LO had same activity of lipase and amylase, but comparing with crabs fed LO, crabs fed FO had higher trypsin activity and lower pepsin activity. Hepatopancreas fatty acid composition changed to reflect the fatty acid composition of the diets. In total, 194 proteins were differentially expressed in the hepatopancreas between the diets. Expression of heat shock proteins was higher in crabs fed LO. Expression of fatty acid synthase, long-chain fatty acid transport protein 4, acyl-CoA delta-9 desaturase, and fatty acid-binding protein 1, was higher in crabs fed FO. Conclusions: The substitution of FO with LO didn’t have any effects on the growth and molting of mitten crab, but could significantly decrease the ability of mitten crab to cope with stress. The high content of HUFAs in the hepatopancreas of mitten crab fed FO is due to the high abundance of the proteins relative to the transport of the HUFAs. These findings provide a reason of the high content of EPA and DHA in crabs fed with FO, and provide new information for the replacement of FO in diets of mitten crab. [ABSTRACT FROM AUTHOR]

Precocity is a common phenomenon among farmed Chinese mitten crab Eriocheir sinensis that significantly affect culture productivity and profitability. This study compared the reproductive performance, offspring quality, proximate and fatty acid composition of pond-reared precocious and normal sexual matured females of E. sinensis . While the average gonado-somatic index (GSI) of the normal female crabs was significantly lower than that of the precocious crabs, fecundity, egg fertilization and hatching rate were significantly higher in the former. On the other hand, comparing various larval quality parameters measured with newly hatched larvae produced by the two types of females, only significant difference detected was dry weight with larvae produced by the normal females having significant higher dry weight. Biochemical analysis showed that eggs produced by precocious females contained a higher water content, but lower DHA, n − 3 PUFA and n − 3 HUFA contents than those produced by normal crabs and egg fertilization and hatching rates were, in general, correlated positively with the biochemical and fatty acid composition of the eggs. However, interestingly, such a correlation was not identified in newly hatched larvae. The results of hepatopancreas and ovarian proximate and fatty acid composition analysis suggested that lower reproductive performance of precocious females is likely related to the deficiencies in PUFA and general poorer nutrient conditions of these crabs. Statement of relevance The Chinese mitten crab, Eriocheir sinensis , is currently farmed throughout China. Precocity, commonly accounts for 15–30% of cultured crab populations, is a major problem for E. sinensis aquaculture. The precocious crabs reach terminal moult at small sizes, hence have low market value. To date, it is unknown whether the precocious crabs are reproductive functional. This study confirmed that precocious E. sinensis could produce viable offspring, and subsequently compared reproductive performance and offspring quality between normal and precocious E. sinensis , providing useful information for aquaculture of the species. [ABSTRACT FROM AUTHOR]

Abstract: The nutritional value of various edible parts of the blue swimmer crab (Portunus pelagicus) was evaluated, and gender differences in terms of edible yield, proximate composition, amino acids, lipid classes and fatty acid content were compared. The results showed that females (44.3%) had a higher edible yield than males (35.9%) (P <0.05). Although higher protein and lipid contents were detected in the meat and gonad of females, the males contained higher docosahexaenoic acid (DHA) (P <0.05). Significant differences in fatty acid composition were also found among various edible parts and between genders (P <0.05). For example, the meat was shown to have higher total highly unsaturated fatty acids (HUFA) (36–39%) than the hepatopancreas (16–18%) or gonads (16–24%). A balanced amino acid composition was found in both meat and gonads. The results obtained from the present study indicate that the meat and ovaries of the blue swimmer crab are one of the healthiest seafoods, and they are also suitable for making processed products. [Copyright &y& Elsevier]

• Nutritional composition and flavor of Eriocheir sinensis from Ya Lake analyzed. • The edible tissues of Ya Lake Eriocheir sinensis had high EPA content. • Eriocheir sinensis muscles in September contained the highest levels of alanine. The edible tissue yield, proximate, fatty acid, and free amino acid composition were examined and compared among Chinese mitten crabs (Eriocheir sinensis) samples from Ya Lake over different months. Regardless of gender, the gonadosomatic index (GSI) was higher in May and June than that in August and September (P < 0.05), whereas the hepatopancreas index (HSI), meat yield (MY), and total edible yield (TEY) were higher in August and September. For proximate composition, regardless of gender, the total lipid content in the hepatopancreas was significantly higher in September than in other months, and the total lipid and protein content in the gonads was the highest. Furthermore, the content of EPA in female hepatopancreas was the highest in August. Regardless of sex, C16:1n7 in muscle was higher in September than in other months (P < 0.05), and the ratio of n-3/n-6 PUFA was the highest. Moreover, females had the highest glutamate and arginine content in their ovaries in August (P < 0.05). Among the muscles, both sexes contained higher levels of alanine and glutamate in September. Thus, the edible tissue yield, nutritional quality, and taste of Ya Lake E. sinensis in September were the best. [ABSTRACT FROM AUTHOR]