Postembryonic development of Nymphon unguiculatum Hodgson 1915 (Pycnogonida, Nymphonidae) from the South Shetland Islands (Antarctica)
Postembryonic development of Nymphon unguiculatum Hodgson 1915 (Pycnogonida, Nymphonidae) from the South Shetland Islands (Antarctica)
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来自南设得兰群岛（南极洲）的 Nymphon unguiculatum Hodgson 1915（Pycnogonida，Nymphonidae）的胚胎后发育
作者：
Esperanza Cano Sánchez;P. López
雄性标本的海蜘蛛种Nymphon unguiculatum，携带鸡蛋，幼虫和后期幼虫在不同的发展阶段，收集了南设得兰群岛岛在水深112和472米，在2006/2007年夏季。在这里，我们描述了外部形态的四个postembryonic阶段（protonymphon，1龄，2龄，3龄）进行这些标本。结果表明：（1）原膜幼虫从卵中孵化;（2）幼虫和仔稚鱼阶段有卵黄储备，并以相对较大的尺寸为特征（3）在几次蜕皮中，幼鱼附着在雄鱼的产卵腿上，（4）有吐丝器;（5）步行腿的发育是顺序性的。本文报道了中华绒螯蟹幼虫和仔虾的发育。unguiculatum与已知的其他pycnogonid物种进行了比较。
Male specimens of the sea spider species Nymphon unguiculatum, carrying eggs, larvae and postlarvae in various stages of development, were collected off the South Shetland Island at water depths between 112 and 472 m in austral summer 2006/2007. Here, we describe the external morphology of four postembryonic stages (protonymphon, instar 1, instar 2, and instar 3) carried by these specimens. We found that (1) protonymphon larvae hatch from the eggs; (2) larvae and postlarval stages have yolk reserves and are characterized by a relatively large size (average body lengths of 0.46, 0.55, 0.65 and 0.73 mm in the successive stages); (3) postlarvae remain on the ovigerous legs of males during several moults; (4) a spinning apparatus is present; (5) the development of walking legs is sequential. The larval and postlarval development of N. unguiculatum is compared with that known from other pycnogonid species.