POLYMORPHISM IN FREE-SWIMMING LARVAE OF HALISARCA DUJARDINI (DEMOSPONGIAE, HALISARCIDA)
Abstract
This paper discusses the embryonic development of Halisarca dujardini Johnston, 1842 (Demospongiae, Halisarcida). Different morphotypes of free-swimming larvae are formed: parenchymella-like, coeloblastula-like larvae and disphaerulae larvae. Larvae with different morphological characters may develop in the same parent and remain morphologically distinct until metamorphosis. We have identified a number of characters that emerge during embryogenesis, determined the developmental stage when they emerge as well as possible morphogenetical processes causing their variability. The complexity of morphogenesis in H. dujardini is indicative of the low level of determination that occurs during embryogenesis.Downloads
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2018-05-23
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