Body structure of marine sponges. VI. Choanocyte chamber structure in the haplosclerida (porifera, demospongiae) and its relevance to the phylogenesis of the group
✍ Scribed by Paul-Friedrich Langenbruch; W. Clifford Jones
- Publisher
- John Wiley and Sons
- Year
- 1990
- Tongue
- English
- Weight
- 948 KB
- Volume
- 204
- Category
- Article
- ISSN
- 0362-2525
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✦ Synopsis
Abstract
The choanocyte chambers of eight different haplosclerid sponge species have been investigated with regard to their histological structure, their relation to the mesohyl, and their arrangement between the canal systems. Two fundamentally different organizational types occur in the investigated sponge species. In Haliclona rosea, H. oculata, H. elegans, H. simulans, H. rava, H. fistulosa, and Acervochalina limbata the choanocytes are separated from the mesohylar tissue, being more or less covered over the outer surface by pinacocytes belonging to the incurrent canal walls. In Haliclona indistincta, on the other hand, the choanocytes are, as in most other Demospongiae, in contact with the mesohyl at their outer surfaces. This indicates that the present order Haplosclerida is polyphyletic and contains sponges of a presumably poecilosclerid origin.