Ultrastructural study of the jaw structures in two species of Ampharetidae (Annelida: Polychaeta)
Ultrastructural study of the jaw structures in two species of Ampharetidae (Annelida: Polychaeta)
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DOI：
10.1111/j.0001-7272.2004.00168.x
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发表时间：
2004-07-01
期刊：
影响因子：
1.2
通讯作者：
Tzetlin, AB
中科院分区：
文献类型：
--
作者：
Tzetlin, AB
本文报道了两种有颌双足科动物（Adercodon pleijeli（Mackie 1994）和Ampharete sp. B）的口腔显微解剖学特征。这两种被研究物种的动物都有14-18个口触手，每个口触手直径约为30 μ m。在这两个物种中，腹咽器官发育良好，位于颊腔的腹侧。它由腹肌球和包埋肌组成。球由后部和前部组成，由深的中间横向沟分开。在这两个物种中，三角形的齿或齿在腹球后部的表面上排列成一个横向的行，就在腹球的后缘的前面。多节香茶菜36个，双足藻B 50个。两个物种的栖息地高度（6-12 μ m）相似。每个牙齿由两个主要层组成。外层（牙齿）是覆盖牙齿的电子致密硬化层。内层由长的微绒毛组成，微绒毛之间有胶原基质。牙层的厚度范围为0.95至0.6 μ m。所研究的蠕虫的颚可能在刮除微污染方面发挥一定的作用。双头鱼科的颌骨的微细结构与多刺鱼科的下颌骨、蚓鱼科、真鳕科和尾鳕科的下颌骨和上颌骨以及其它针状动物的颌骨非常相似。这种类型的颌骨的特点是无限增长和缺乏替代。在一些较小的双头鱼科中，颚的出现被认为是一种无形状态。
Two species of jaw bearing Ampharetidae (Adercodon pleijeli (Mackie 1994) and Ampharete sp. B) were investigated in order to describe the microanatomy of the mouth parts and especially jaws of these enigmatic polychaetes. The animals of both studied species have 14-18 mouth tentacles that are about 30 mum in diameter each. In both species, the ventral pharyngeal organ is well developed and situated on the ventral side of the buccal cavity. It is composed of a ventral muscle bulb and investing muscles. The bulb consists of posterior and anterior parts separated by a deep median transversal groove. In both species, the triangular teeth or denticles are arranged in a single transversal row on the surface of the posterior part of the ventral bulb just in front of its posterior edge. There are 36 denticles in Adercodon pleijeli and 50 in Ampharete sp. B. The height of the denticles (6-12 mum) is similar in both species. Each tooth is composed of two main layers. The outer one (dental) is the electron-dense sclerotized layer that covers the tooth. The inner one consists of long microvilli with a collagen matrix between them. The thickness of the dental layer ranges from 0.95 to 0.6 mum. The jaws of the studied worms may play a certain role in scraping off microfouling. The fine structure of the jaws in Ampharetidae is very similar to that of the mandibles of Dorvilleidae, the mandibles and the maxillae of Lumbrineridae, Eunicidae and Onuphidae, and the jaws of other Aciculata. This type of jaw is characterized by unlimited growth and the absence of replacement. The occurrence of jaws in a few smaller Ampharetidae is considered as an apomorphic state.