Department of Life Science, Tunghai University, Taichung 407, Taiwan.
Department of Life Science, Tunghai University, Taichung 407, Taiwan; Center for Ecology and Environment, Tunghai University, Taichung 407, Taiwan.
Comp Biochem Physiol A Mol Integr Physiol. 2020 Oct;248:110753. doi: 10.1016/j.cbpa.2020.110753. Epub 2020 Jul 10.
Gills and the antennal gland are ion-regulatory organs in crabs. Previous studies have suggested that the differences in the morphology and ion regulation of gills and accessory respiratory organs between ocypodid and grapsid species are related to their distinct evolutionary transition to land habitats. In addition, Na, K-ATPase (NKA) activity and Na and NH regulation in the antennal gland differ between ocypodid and grapsid species, which had different terrestrial adaptation trajectories. This study used five Ocypodoidea species and three Grapsoidea species from the intertidal and supratidal zones to further investigate the differences in ion regulation and NKA activity in the antennal gland between these crab families in different habitats. Crabs were transferred to 5 practical salinity unit (PSU) water, and osmolality, Na and Cl concentrations in the urine and hemolymph, and NKA activity in the antennal gland were examined. Phylogenetic ANOVA results showed that the NKA activity in the antennal gland was higher in the ocypodid than grapsid groups, and Moran's I autocorrelation analysis also indicated that NKA activity in the antennal gland was phylogenetically correlated among crabs. K-means clustering showed a difference among the crabs in the crabs' Na and Cl concentrations in the urine/hemolymph, NKA activities in the antennal gland and gill 6, and number of pairs of gills. Crabs with relatively high antennal gland NKA activity were found not only in the Ocypode species, which are better adapted to terrestrial environments, but also in two intertidal species of Gelasiminae. In conclusion, part of the Ocypodidae lineage may have a) the ability to reabsorb Na and b) higher NKA activity in the antennal gland than other families, and this phenomenon is phylogenetically correlated in Ocypodoidea and Grapsoidea. The physiological diversity in osmoregulation among intertidal and costal species provides a base to further investigate their ecological niches and guilds.
鳃和触角腺是螃蟹的离子调节器官。先前的研究表明，扇蟹科和方蟹科物种之间鳃和辅助呼吸器官的形态和离子调节的差异与它们向陆地栖息地的独特进化转变有关。此外，触角腺中的 Na、K-ATP 酶（NKA）活性和 Na 和 NH 的调节在扇蟹科和方蟹科物种之间存在差异，这些物种具有不同的陆地适应轨迹。本研究使用来自潮间带和潮上带的五个扇蟹科物种和三个方蟹科物种，进一步研究了这些不同生境下蟹类家族之间触角腺离子调节和 NKA 活性的差异。将螃蟹转移到 5 个实用盐度单位（PSU）的水中，检查尿液和血淋巴中的渗透压、Na 和 Cl 浓度以及触角腺中的 NKA 活性。系统发育方差分析结果表明，触角腺中的 NKA 活性在扇蟹科中高于方蟹科，Moran's I 自相关分析也表明螃蟹之间的触角腺 NKA 活性在系统发育上是相关的。K-均值聚类显示，在螃蟹的尿液/血淋巴中的 Na 和 Cl 浓度、触角腺和鳃 6 的 NKA 活性以及鳃的对数方面，螃蟹之间存在差异。具有相对较高触角腺 NKA 活性的螃蟹不仅存在于适应陆地环境更好的地蟹属物种中，也存在于两个潮间带的扇蟹科物种中。总之，部分扇蟹科可能具有 a）重吸收 Na 的能力和 b）触角腺中 NKA 活性高于其他科，这种现象在扇蟹目和方蟹目中具有系统发育相关性。潮间带和沿海物种在渗透调节方面的生理多样性为进一步研究它们的生态位和 guilds 提供了基础。
