ISSN:
0362-2525
Keywords:
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Medicine
Notes:
The morphology of the entoproct Barentsia gracilis (M. Sars, 1835), has been studied primarily by routine light microscopy techniques supplemented with observations by electron microscopy. In general, the B. gracilis adult is similar in structure to other members of the Pedicellinidae. Differences noted include: the presence of conspicuous fibers, probably collagenous, which appear to reinforce the stalk- calyx connection, the presence of a distinct glandular- appearing area (also present in the larva) of unknown function, and the presence of two rows of latero- frontal cilia on the tentacles. The first detailed morphology of an entoproct larva is also presented and the striking similarity to the adult noted. Due to the confused state of Barentsia systematics, it was found that B. gracilis, B. geniculata, and B. benedeni may very well be the same animal. This is due to the great variability, apparently due to ecological factors, found in the key taxonomic characters such as stalk morphology. The feeding behavior of the adult is described and the larval feeding and rejection mechanism is reported for the first time. The larva, while still in the brood pouch, uses its ciliary girdle to remove food from the parent's food groove. The larval feeding current is generally similar to that of the adult, with modifications which are related to the lack of tentacles in the larva. The larva differs from the adult in having special ciliated rejection pathways for the removal of excess food particles.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jmor.1051160302
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