Hemolymph osmotic, ionic status, and branchial Na+/K+-ATPase activity under varying environmental conditions in the intertidal grapsid crab, Gaetice depressusd

Abstract

In the current study, ten elements contents (Fe, Zn, Mn, Cu, Cr, Co, Ni, Cd, Pb and Hg) have been measured in muscle and liver of four pelagic fish species (Engraulis encrasicolus, Sardina pilchardus, Scomber japonicus and Trachurus trachurus) from the north-west African coast (South Atlantic Moroccan coast), collected during summer and autumn seasons (July and December 2013, respectively). Significant differences in metal contents were found between the different species (p \ 0.05). Metals levels were also much higher in liver than those recorded in muscle tissues. The concentrations of Fe, Zn, Cd, Co, Cu and Pb were significantly higher in mackerel liver (p \ 0.05).While, in muscle, anchovy presents a higher content of Mn, Cu, Cr, Ni and Pb. A high level of cadmium was recorded in liver of the different species which can be attributed to an anthropogenic source (phosphate industry) and to natural sources (upwelling activities). The main concentration of toxic elements (Cd, Pb and Hg) recorded in the four edible muscles of pelagic fish species, under study, were below the established values by the European Commission Regulations and show that their effect on the consumers health can be considered as negligible.

Osmotic/ionic status of body fluids in the euryhaline cephalopod suggest possible parallel evolution of osmoregulation

“…In this study, we observed significant increases in the Na + /K + -ATPase activity of gills 6 and 8 one week after acclimation to 20-ppt salinity ( Fig. 4 ), similarly to the posterior gills in many crustaceans structurally and functionally specialized as the principal site of osmoregulatory ion transport 30 37 38 40 . The involvement of other transport proteins and transport-related enzymes (e.g., a Na + /H + antiporter, carbonic anhydrase, Cl − /HCO3 − exchanger, Na + /K + /2Cl − cotransporters, and V-ATPases) and/or the acid-base balance/ammonium transport cannot be excluded 41 , but little is known about the related parameters during acclimation to different salinities.…”

“…Slopes resulting from regression analysis between hemolymph osmotic/ionic concentrations and those in medium at given salinity have been used to determine the ability of aquatic organisms to osmo- and ionoregulate 4 5 37 38 . The closer the deviation of slope to the isosmotic and isoionic line (slope = 1), the lower the ability of the organisms to osmo- and ionoregulate.…”

“…Regarding Ca 2+ changes ( Figs 2 C and 3 C), the regulation was unclear because we could not measure the relevant free moiety, but the decreased urine Ca following the exposure to BW suggests reabsorption of Ca 2+ from urine. As in crustaceans 37 38 42 , hemolymph complexed calcium may serve as an internal reserve for maintaining free Ca 2+ levels in the hemolymph. In addition to the Ca 2+ channel, Ca 2+ -ATPase and Na + /Ca 2+ exchanger, the potential energy of the Na + gradient established by the branchial Na + /K + -ATPase activity may also affect transport of Ca 2+ in hemolymph.…”

Molecular Cloning of the Calcyclin-Binding Protein Gene from the Swimming CrabPortunus trituberculatusand Its Roles in Salinity Stress Adaptation

“…The osmoregulation mechanisms for the crustacean species, however, are not well studied so far (Towle & Weihrauch 2001, Luquet et al 2005. It was also reported that the potential energy of Na + gradient could affect the Ca 2+ channel, Ca 2+ -ATPase, Na + /Ca 2+ exchanger and the Ca 2+ transportation in the hemolymph system of the crustaceans (Roer & Dillaman 1993, Nanba et al 2012). The fluctuant salinity might alter the Ca 2+ levels that might be correlated with the CacyBP protein.…”

Effects of salinity on the ions important and sodium‐potassium ATPase in osmoregulation, cortisol, amino acids, digestive and immune enzymes in Scylla paramamosain during indoor overwintering

“…Salinity is an important factor affecting osmoregulation in S. paramamosain (Wang, Tang, Wei, Lu, Mu, et al, 2018; Wang, Wei, et al, 2019). Ion concentrations (K + , Cl ‐ and Na + ) and Na + /K + ‐ATPase activity are important indicators reflecting osmoregulation ability (Geng, Tian, et al, 2016; Geng, Tong, Jiang, & Xu, 2016; Nanba et al., 2012).…”