Salt tolerance reflects ecophysiological adaptation, and the wide-ranging distribution of the Brachyura mirrors their ability to adjust body fluid concentrations. The gill (Na⁺, K⁺)-ATPase underpins such hyper/hypo-regulatory mechanisms. We evaluate osmotic and chloride regulation in Callinectes danae after 10 days acclimation to a wide salinity range (5–50 ‰S), accompanying alterations in hemolymph osmolality and [Cl⁻] during hypo- (15 ‰S) or hyper- (45 ‰S) osmotic challenge. Further, we investigate posterior gill (Na⁺, K⁺)-ATPase kinetics, α-subunit immunolocalization and its mRNA and protein expression (15, 30 and 40 or 45 ‰S). The crab is a moderate, asymmetrical hyper/hypo-osmoregulator but is a strong, asymmetrical hyper/hypo-chloride regulator. Hyper-regulation at low salinity is sustained by a threefold increase in (Na⁺, K⁺)-ATPase activity, a 3.5-fold increase in α-subunit mRNA expression and 1.6-fold increase in protein expression. α-Subunit signal is highest in 15 ‰S-acclimated crabs, and is uniformly distributed throughout the ionocytes and pillar cells. Activity in 30- and 40% S-acclimated crabs is similar. Affinity for ATP and Na⁺ increases on high salinity acclimation but decreases for ouabain. K⁺ apparent affinity is independent of salinity, while that for Mg²⁺ decreases and for NH₄⁺ increases with increasing salinity. A high-affinity ATP-binding site disappears on acclimation at any salinity. F_OF₁- and Na⁺- or K⁺-ATPase activities decrease with increased salinity. Hemolymph chloride hypo-regulation depends little on gill (Na⁺, K⁺)-ATPase activity. Hyper-, and hypo-osmotic and ionic regulatory capabilities in C. danae are intricate physiological processes underpinned by multifarious gill (Na⁺, K⁺)-ATPase kinetics and altered mRNA and protein expressions.

耐盐性反映了生态生理适应性，Brachyura的广泛分布反映了它们调节体液浓度的能力。ill（Na ⁺，K ⁺）-ATPase增强了这种高/低调节机制。我们评估了适应性较宽的盐度范围（5–50‰S）后10天的Callinectes danae中的渗透和氯化物调节，以及在低（15‰S）或高（45‰ ）时伴随的血淋巴渗透压和[Cl ⁻ ]的变化S）渗透挑战。此外，我们调查后g （Na ⁺，K ⁺）-ATPase动力学，α-亚基免疫定位及其mRNA和蛋白质表达（15、30和40或45‰S）。螃蟹是中等，不对称的高/次渗透调节剂，但是强壮的，不对称的高/次氯调节剂。低盐度下的过度调节通过（Na ⁺，K ⁺）-ATPase活性增加三倍，α-亚基mRNA表达增加3.5倍和蛋白质表达增加1.6倍来维持。在适应15‰S的螃蟹中，α亚基信号最高，并且均匀分布在整个离子细胞和柱状细胞中。在适应30％和40％S的螃蟹中的活性相似。ATP和Na ^+的亲和力在高盐度适应下增加，而哇巴因则降低。钾⁺表观亲和力与盐度无关，而Mg ²⁺随盐度的增加而降低，而NH ₄ ⁺随盐度的增加而增加。在任何盐度条件下，高亲和力的ATP结合位点都会消失。F _O F _1-和Na ⁺ -或K ⁺ -ATPase活性随盐度增加而降低。氯化血氯化物的低调节几乎不依赖于g （Na ⁺，K ⁺）-ATPase活性。在超支和低渗透和离子调节能力C.达娜厄是由五花八门鳃支撑复杂的生理过程（钠⁺，K ⁺）-ATPase动力学和改变的mRNA和蛋白质表达。