当前位置： SCI文献检索 > PARASITOLOGY RESEARCH期刊下所有文献 > Ultrastructural characteristics of the caeca of basal polyopisthocotylean monogeneans of the families Chimaericolidae and Hexabothriidae parasitic on cartilaginous fishes.

Ultrastructural characteristics of the caeca of basal polyopisthocotylean monogeneans of the families Chimaericolidae and Hexabothriidae parasitic on cartilaginous fishes.

Abstract：

:Ultrastructural differences are shown between the caecal organization in three blood-feeding polyopisthocotylean monogeneans, i.e., the chimaericolid Chimaericola leptogaster from the holocephalan Chimaera monstrosa and two hexabothriids, Callorhynchocotyle callorhynchi from the holocephalan Callorhynchus capensis and Rajonchocotyle emarginata from the elasmobranch Amblyraja radiata. In C. leptogaster, digestive cells and connecting syncytium, joined close to the luminal surface by septate junctions, are arranged alternately along the caecal epithelial wall; the nuclear regions of both cell types are sunk below the general level of the caecal epithelium; a concave depression on the apical margin of the digestive cells bears lamellae; and this depression is covered by a lamellate bubble formed by thin projections emanating from the connecting syncytium. The luminal surface of the connecting syncytium is covered with outgrowths terminating in the form of long, narrow processes. In R. emarginata and C. callorhynchi, the predominant digestive cells are at different stages of development and occur in groups, developing digestive cells bulge into the caecal lumen from the connecting syncytium with contact sites present close to the luminal surface, and the luminal surface structures of both the connecting syncytium and the digestive cells are short lamellae. In these two hexabothriids, a holocrine (or apocrine) process for the elimination of digestive product is assumed via the detachment of fully differentiated, bulging digestive cells. Free, apparently sloughed digestive cells and residual bodies are present within the caecal lumen, and replacement digestive cells are numerous in the connecting syncytium. In the chimaericolid, free bubbles containing residual bodies and portions of digestive cells filled with degenerating digestive vesicles occur in the caecal lumen along with large amounts of male and female reproductive material. The usefulness of characteristics of the caecal ultrastructure as taxonomic traits at the family level is discussed.

journal_name

Parasitol Res

journal_title

Parasitology research

authors

Poddubnaya LG,Hemmingsen W,Reed C,Gibson DI

doi

10.1007/s00436-015-4464-5

subject

Has Abstract

pub_date

2015-07-01 00:00:00

pages

2599-610

issue

eissn

0932-0113

issn

1432-1955

journal_volume

114

pub_type

杂志文章

在线工具

Ultrastructural characteristics of the caeca of basal polyopisthocotylean monogeneans of the families Chimaericolidae and Hexabothriidae parasitic on cartilaginous fishes.