CROSSOBOTHRIUM LACINIATUM AND DEVELOPMENTAL STIMULI IN THE CESTODA
| Autor: | W. C. Curtis |
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| Rok vydání: | 1903 |
| Předmět: | |
| Zdroj: | The Biological Bulletin. 5:125-142 |
| ISSN: | 1939-8697 0006-3185 |
| DOI: | 10.2307/1535516 |
| Popis: | In the spiral valve of the "sand shark" (Carcharias littoralis) taken from the Woods Holl region there is found in a large majority of the specimens examined the Cestode, Crossobothrium laciniatum. This genus and species was first described by Linton ("Rept. U. S. F. Com." for I886), and in subsequent papers appearing in the same publication or in the " U. S. F. C. Bulletin," he has added further important notes, the whole making an accurate and satisfactory systematic description. A striking feature of the species is the remarkable clearness with which the important features of Cestode structure can be demonstrated. The water vascular system, main trunks and flame-cells can be seen in the fresh specimen with the greatest ease. Almost every detail of the complicated reproductive organs is seen in well-stained whole mounts of the motile proglottids and much of this in specimens freshly prepared. The mode of using the suckers on the head, the activities of the motile proglottids and their mode of egg-laying and the development of these eggs in sea-water as far as the six-hooked embryo are all easily demonstrated. Moreover, there occurs in the cystic duct of the squeteague (Cynoscion regalis), a not uncommon food of the "sand shark," a tetrabothrian larva which, if not the larva of Crassobothrium laciniatum, probably belongs to some very closely related form. This larva, which was first described and figured by Linton (" Rept. U. S. F. Corn.," I886), is again an extremely favorable object for study. If it is possible to obtain conclusive evidence that this tetrabothrian larva of the squeteague is indeed the larva of C. laciniatum, we shall have but one gap in the life history of this species, viz., the transfer to the squeteague of the six-hooked embryo which develops in the open ocean. Such favorable material it seemed to me might present, upon careful examination, facts which would be suggestive along the |
| Databáze: | OpenAIRE |
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