Abstract

The morphology of the mandibles in the lobster shrimps Boasaxius princeps and Leonardsaxius amurensis is described at different stages of ontogenesis. The incisor process of the mandibles in axiid zoeae is flattened antero-posteriorly, with three stout terminal teeth; the molar process is broad, the grinding surface is formed by transverse cuticular ridges and bears a fringe of brush-like projections on the anterior edge of the left mandible and on the posterior edge of the right mandible; between the terminal teeth of the incisor process and the molar process is a spine row formed by groups of spines. The general plan of the structure of the mandibles is retained in all zoeal stages; the number of transverse ridges on the molar process and the number of spine groups in the spine row increase as the larvae develop. In the megalopa stage, the mandible shape changes: the incisor process becomes broad and concave, the molar process is perpendicular to it; spines and ridges on the grinding surface of the molar process become reduced, small spines on the incisor process are retained on the cutting edge. Adult lobster shrimp lack cuticular structures on the molar and incisor processes of the mandibles. Despite the marked differences in the adult mandible morphology, the mandibles of the zoeae of Axiidea show similarity to the mandibles of the larvae of some caridean shrimps (e.g., the family Lysmatidae).

中文翻译：

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幼虫和成年龙虾虾下颌下颚的形态学（Bocapaxius princeps和Leonardsaxius amurensis）（十足目：轴突：轴突）

摘要

龙虾虾Boasaxius princeps和Leonardsaxius amurensis的下颌骨形态在本体形成的不同阶段进行了描述。下颌前突的下颌切牙过程是前后扁平的，末端有三个粗壮的牙齿。磨牙过程很宽，磨削表面由横向的表皮隆起形成，在左下颌骨的前边缘和右下颌骨的后边缘带有刷状突起的边缘。在切牙过程和磨牙过程的末端牙齿之间的是由脊椎群形成的脊柱行。下颌骨结构的总体计划在所有阶段均得到保留；随着幼虫的发育，磨牙过程中的横向脊的数量和脊柱排中的脊柱组的数量增加。在半生不孕阶段，下颌骨的形状发生变化：门牙过程变得宽而凹，磨牙过程与之垂直；磨牙过程的磨削表面上的刺和脊变少，切牙过程中的小刺保留在切削刃上。成年龙虾虾在下颌的磨牙和切牙过程中缺乏表皮结构。尽管成年下颌骨形态存在显着差异，但无翅A科动物的下颌骨与某些直齿虾（例如，裂蝇科）的幼虫的下颌骨具有相似性。