Étude du développement d'Halistemma rubrum (Vogt, 1852) siphonophore physonecte Agalmidae = Study of the development of Halistemma rubrum (Vogt, 1852) Siphonophora, Physonecta, Agalmidae
Carré, D. (1971). Étude du développement d'Halistemma rubrum (Vogt, 1852) siphonophore physonecte Agalmidae = Study of the development of Halistemma rubrum (Vogt, 1852) Siphonophora, Physonecta, Agalmidae. Cah. Biol. Mar. 12(1): 77-93, 3 plates
In: Cahiers de Biologie Marine. Station Biologique de Roscoff: Paris. ISSN 0007-9723; e-ISSN 2262-3094, more
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| Abstract |
Metschnikoff (1874) and Woltereck (1905) gave 2 contradictory descriptions of the morphology of the development of Halistemma rubrum. The author confirms the observations of Metchnikoff and studies the histology of the main larval stages. He shows that segmentation does not lead to a morula, contrary to general opinion, but to a blastula of a particular type, which changes into a gastrula by a primary delamination. At the planula stage an ectodermal invagination gives the bud of pneumatophore, which in the neighbourhood of this organ, a swimming bell develops from a medusal nodule, isolated by delamination of the ectoderm. The author compares development of the pneumatophore with that of the nectophore and concludes that these 2 organs have different modes of differentiation, which preclude any homology between them. |
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