Journal of Experimental Marine Biology and Ecology ( IF 2 ) Pub Date : 2021-03-23 , DOI: 10.1016/j.jembe.2021.151547 Murilo Zanetti Marochi , Giovanna Carstens Castellano , Carolina Arruda Freire , Setuko Masunari
In semi-terrestrial crustaceans, mothers and the carried embryos form a unit. The ideal conditions for embryonic development place a sustained demand on the mothers' energy budget. A particular challenge for this unit is the transition between terrestrial and aquatic environments. Ecophysiological information on mothers and embryos contributes to the understanding of evolutionary pathways and constraints of terrestrialization in crabs. We evaluated the effects of 6, 12, and 18 h of water deprivation on embryonic development and maternal physiology of the tree-climbing crab Aratus pisonii (H. Milne Edwards, 1837). Specifically, we determined the effect of water deprivation on egg volume, osmolality, and larval survival, as well as on maternal body mass, hemolymph osmolality, and branchial carbonic anhydrase activity (CAA). We hypothesized that longer periods of water deprivation would negatively affect larvae viability, as well as disrupt the physiology of brooding females. Embryonic development, larval survival, and the mother's physiology were only altered after 18 h of water deprivation, possibly due to dehydration and/or the accumulation of metabolic wastes that could not be excreted in the absence of water. Osmolality was higher in females than in their eggs. CAA of the anterior gills was higher in ovigerous than in non-ovigerous females, possibly due to the increase in respiratory demands caused by carrying eggs. Our results confirmed that the gestation period represents a metabolically expensive period for mother crabs and that water deprivation of 18 h was critical for the embryos' survival.
中文翻译:
在半陆地环境中携带卵子:爬树蟹Aratus pisonii对母亲和胚胎缺水的生理反应
在半陆生甲壳类动物中,母亲和所携带的胚胎形成一个单位。胚胎发育的理想条件对母亲的能量预算有持续的需求。该部门面临的一个特殊挑战是陆地和水生环境之间的过渡。有关母亲和胚胎的生态生理信息有助于了解螃蟹的进化途径和陆地异化的限制。我们评估了缺水6、12和18 h对爬树蟹Aratus pisonii的胚胎发育和母体生理的影响(H. Milne Edwards,1837年)。具体来说,我们确定了缺水对卵量,重量克分子渗透压浓度和幼虫存活率以及对孕妇体重,血淋巴重量克分子渗透压浓度和分支碳酸酐酶活性(CAA)的影响。我们假设较长时间的缺水会对幼虫的生存能力产生负面影响,并破坏育雏女性的生理机能。仅在缺水18小时后,胚胎发育,幼虫存活和母亲的生理才会发生变化,这可能是由于脱水和/或代谢废物的积聚,而这些废物在缺水的情况下无法排泄。女性的渗透压高于其卵。卵中前g的CAA高于未卵中的雌性,这可能是由于携带卵引起的呼吸需求增加所致。