Development of Perviata and Vestimentifera (Pogonophora)
Existing knowledge of the embryonic and larval development of perviate and vestimentiferan pogonophorans is reviewed. A form of spiral cleavage has been reported from both groups, but further clarification is desirable. The perviates studied have large yolky eggs, incubated in the maternal tube to a ciliated settlement stage. Others with smaller eggs are still unstudied, but may have pelagic larvae. Vestimentiferans have small eggs and pelagic, non-feeding larvae. Comparisons of the development of perviates with that of vestimentiferans lead to the conclusion that the two groups belong to one higher taxon. An annelidan relationship is indicated because the ciliated settlement stages of both are like annelid trochophores in their ciliation and in the way they develop chaetae initially on two segments.
Key wordsPogonophora embryo larva settlement juvenile growth
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