Sperm ultrastructure is examined in representatives of five genera of the nudibranch gastropod family Chromodorididae: (Chromodoris, Hypselodoris, Glossodoris, Risbecia and Pectenodoris) and the results compared with previous work on other gastropods, especially other nudibranchs. As chromodoridid phylogeny is still incompletely understood, this study partly focuses on the search for new and as yet untapped sources of informative characters. Like spermatozoa of most other heterobranch gastropods, those of the Chromodorididae are elongate, complex cells composed of an acrosomal complex (small, rounded acrosomal vesicle, and columnar acrosomal pedestal), a condensed nucleus, sub-nuclear ring, a highly modified mid-piece (axoneme + coarse fibres surrounded by a glycogen-containing, helically-coiled mitochondrial derivative) and terminally a glycogen piece (or homologue thereof). The finely striated acrosomal pedestal is a synapomorphy of all genera examined here, but interestingly also occurs in at least one dorid (Rostanga arbutus). Substantial and potentially taxonomically informative differences were also observed between genera in the morphology of the nucleus, the neck region of the mid-piece, and also the terminal glycogen piece. The subnuclear ring is shown for the first time to be a segmented, rather than a continuous structure; similarly, the annular complex is shown to consist of two structures, the annulus proper and the herein-termed annular accessory body.

中文翻译：

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裸鳃科五属的比较精子超微结构（腹足纲：后鳃纲）

对裸鳃类腹足动物科 Chromodorididae 的五个属的代表进行了精子超微结构检查：（Chromodoris、Hypselodoris、Glossodoris、Risbecia 和 Pectenodoris），并将结果与​​之前对其他腹足动物，尤其是其他裸鳃类动物的工作进行了比较。由于 chromodoridid 系统发育仍未完全了解，本研究部分侧重于寻找新的和尚未开发的信息特征来源。像大多数其他异分支腹足动物的精子一样，色斑科的精子是细长的复杂细胞，由顶体复合体（小的圆形顶体囊泡和柱状顶体基座）、凝聚核、亚核环、高度修饰的中段组成（轴丝 + 粗纤维被含糖原包围，螺旋状线粒体衍生物）和末端糖原片段（或其同源物）。细条纹的顶体基座是这里检查的所有属的突触，但有趣的是，它也出现在至少一个 dorid (Rostanga arbutus) 中。在细胞核、中间部分的颈部区域以及末端糖原部分的形态方面，在属之间也观察到了实质性和潜在的分类学信息差异。亚核环首次显示为分段结构，而不是连续结构；类似地，环形复合体被显示为由两个结构组成，环本身和此处称为环形附件主体。但有趣的是，它也发生在至少一种 dorid (Rostanga arbutus) 中。在细胞核、中间部分的颈部区域以及末端糖原部分的形态方面，在属之间也观察到了实质性和潜在的分类学信息差异。亚核环首次显示为分段结构，而不是连续结构；类似地，环形复合体被显示为由两个结构组成，环本身和此处称为环形附件主体。但有趣的是，它也发生在至少一种 dorid (Rostanga arbutus) 中。在细胞核、中间部分的颈部区域以及末端糖原部分的形态方面，在属之间也观察到了实质性和潜在的分类学信息差异。亚核环首次显示为分段结构，而不是连续结构；类似地，环形复合体被显示为由两个结构组成，环本身和此处称为环形附件主体。