The influence of habitat on metabolic and digestive parameters in an intertidal crab from a SW Atlantic coastal lagoon (original) (raw)
Related papers
Philosophical Transactions of the Royal Society B: Biological Sciences, 2020
Dungeness crabs (Metacarcinus magister) are ecologically and economically important in the coastal Northeast Pacific, yet relatively little is currently known about their feeding behaviour in the wild or their natural diet. Trophic biomarkers, such as fatty acids (FA), can be used to reveal trophic interactions. We used two feeding experiments to assess differences in FA composition of juvenile crabs fed different known foods to evaluate how they modify and integrate dietary FA into their own tissues and determine whether crab FA reflect diet changes over a six-week period. These experimental results were then compared with the FA signatures of wild caught juvenile crab with undetermined diets. We found that juvenile Dungeness crabs fed different foods assimilated dietary FA into their tissues and were distinct in their FA signatures when analysed with multivariate statistics. Experimentally fed juvenile crabs contained greater proportions of the most abundant long-chain polyunsatur...
Crustaceana, 2008
Changes in enzymatic activities and protein content of leg muscle and hepatopancreas tissue of two deep-sea crabs were studied after 34 days of food deprivation. Geryon longipes and Bythograea thermydron are the most abundant deep-sea crab species in their respective environment. Geryon longipes dwells on the middle and lower slope of the northwestern Mediterranean Sea and has a bathymetric range between 450 and 1950 m depth. Bythograea thermydron dwells in Pacific hydrothermal vent sites and has a bathymetric range between 2000 and 3000 m depth. After 34 days under laboratory conditions, citrate synthase activities in the hepatopancreas of G. longipes and B. thermydron were found to be much lower in food-deprived crabs compared to fed crabs. In both species, no lactate dehydrogenase activity was detected in hepatopancreas tissue, and no food deprivation effects were observed for either lactate dehydrogenase or citrate synthase activities in leg muscle tissue. No changes in protein were found after 34 days of food deprivation, either. Enzyme activities of fed and food-deprived specimens maintained in the laboratory encompassed the natural range of variation measured in freshly caught crabs of both species. Lactate dehydrogenase, citrate synthase, and protein content of freshly caught specimens of G. longipes were significantly lower than in freshly caught specimens of B. thermydron. The results are discussed taking into account the surrounding environmental features both species encounter and from the point of view of the potential use of citrate synthase activity as an indicator of nutritional condition in deep-sea crustaceans.
The feeding preference of the sesarmid crab Perisesarma bidens was investigated when offered different diets: Enteromorpha intestinalis (algae), Kandelia obovata leaves, and propagules. Nutritional value of food, its assimilation, and fates were evaluated using a combination approach of the fatty acids (FAs) and C/N ratios. When offered a mixed diet, male crabs preferred algae than leaves and/or propagules, while a female preference was equally for leaves and algae but less than propagules. The nutritional value of algae was higher as indicated by low C : N ratios and high ω3/ω6 ratios than leaves and propagules. FAs comparison of tissues and faeces indicated that crabs efficiently assimilate essential fatty acids (EFAs) from a given diet in the order of algae greater than leaves and propagules. Despite of sesarmid crabs being a mangrove leaf-eater, E. intestinalis can potentially be important source of nitrogen supplement for P. bidens under mangrove forests.
Do fatty acid profiles help to explain sesarmid crabs food choice
We evaluate the use of the combination approach of fatty acid (FA) profiles and Carbon/Nitrogen ratios to investigate the feeding preference of the sesarmid crab Perisesarma bidens on different diets. The alga Enteromorpha intestinalis, Kandelia obovata leaves and propagules were used in a laboratory feeding assay. Consumption rates of P. bidens were higher in the order of algae= leaves>propagules. C/N ratios indicate that P. bidens significantly assimilates both nitrogen and carbon from algae, nitrogen but not carbon from brown leaves, and only carbon from propagules. A comparison of FAs in tissues and faeces indicated that crabs efficiently assimilate essential FAs (EFAs) from a given diet in the order of algae>leaves>propagules. Results of higher EFA ratios ( 3/ 6) match with that of low C/N ratios indicating that algae had higher nutritional value than leaves and propagules. FA profiles suggested that brown leaf palatability was due to decomposing activity by bacteria and fungi in the leaf tissues. These data suggest that the combination of FA profiles and C/N ratios provides a better understanding of the diet choice by sesarmid crabs.
Comparative biochemistry and physiology. Part B, Biochemistry & molecular biology, 2017
We determined the activity of glyceroneogenesis from [2-(14)C]-pyruvate, the phosphoenolpyruvate carboxykinase activity, [2-(14)C]-pyruvate oxidation and total lipid levels in the hepatopancreas of the crab Neohelice granulata fed with a carbohydrate-rich (HC) diet or a high-protein (HP) diet and then subjected to 5weeks of starvation, in summer and winter, to determine whether the seasonal adjustments of lipid metabolism to food scarcity are modulated by the composition of the diet previously given to the crabs. The results demonstrated that glyceroneogenesis is an active pathway in N. granulata hepatopancreas, and is regulated by seasonal variations, diet composition and starvation. This study showed that in summer the increase in the hepatopancreas glyceroneogenesis activity is among the strategies used by N. granulata fed an HP diet, to maintain the triglyceride/fatty acid cycle during starvation, a normal condition in the biological cycle of this crab. However, the administrati...
2020
Crab is considered as a vital member of decapod crustaceans belonging to the shellfish group and living in marine, brackish, or freshwaters habitat. Crabs can be extensively found in shallow waters, especially in mangrove areas and estuaries (Wan Yusof et al., 2019). In Bangladesh, crabs particularly dwell in the estuaries, tidal rivers of the Sundarbans shrimp polders (Khan and Alam, 1992). Crabs are good exportable fishery ARTICLE INFO ABSTRACT Article History: Received: Sept. 30, 2020 Accepted: Nov. 29, 2020 Online: Dec. 12, 2020 _______________
Iheringia. Série …, 2008
The goal of this study was to evaluate the effect of a high-carbohydrate diet (HC) and a high-protein diet (HP) on the metabolism of the crayfish Parastacus brasiliensis (Von Martens, 1869), collected in different seasons and maintained in the laboratory for 15 days. Crayfish were collected monthly from January 2002 to January 2004 at São Francisco de Paula, Southern Brazil, in Guarapirá stream. In the laboratory, the animals were kept submerged in aquariums under controlled conditions. They were fed ad libitum, for 15 days with either a HC or HP diet. At the end of this period, haemolymph samples were collected, as were hepatopancreas, gills, and abdominal muscle that were removed for determination of glycogen, free glucose, lipids, and triglycerides. The haemolymph samples were used for determination of glucose, proteins, lipids, and triglycerides. Statistical analysis (ANOVA) revealed significant seasonal differences in biochemical composition in crayfish maintained on HC or HP diets. Independent of the diets offered to the animals and the controlled conditions for 15 days, the indications of seasonality were unchanged. The observed changes seemed to be related to the reproductive period. Moreover, the HC diet increased all energy reserves in adult parastacids, which may aid in reproduction.