title: Cation composition and osmolality of the hemolymph of the terrestrial crab Gecarcinus lagostoma.
abstract: Hemolymph cation concentration and osmolality are reported for male and female specimens of the terrestrial crab Gecarcinus lagostoma collected on Trindade Island, Brazil (20 degrees 36'36" S and 29 degrees 19'26" W). Data for 9 female crabs weighing 133.7 +/- 25.4 g (mean +/- SD) were: osmolality, 816 +/- 85 mOsm/kg H2O; Na+, 357 +/- 55; K+, 7.9 +/- 0.8; Ca2+, 33.5 +/- 2.8 and Mg2+, 15.6 +/- 2.5 mEq/l. There were no significant differences between the female (N = 9) and male (N = 9) hemolymph parameters. The hemolymph Na+, K+, Ca2+ and Mg2+ concentrations and osmolality of G. lagostoma were higher (P less than 0.01) than those of U. cordatus, a previously studied Brazilian gecarcinid crab. These differences are probably due to the higher degree of terrestriality of G. lagostoma compared to U. cordatus.
mesh_terms: D000818:Animals; D003386:Brachyura; D002118:Calcium / Q000097:blood; D005260:Female; D006458:Hemolymph / Q000032:analysis*; D008274:Magnesium / Q000097:blood; D008297:Male; D009994:Osmolar Concentration; D011188:Potassium / Q000097:blood; D012964:Sodium / Q000097:blood
chemical_list: D012964:Sodium; D008274:Magnesium; D011188:Potassium; D002118:Calcium