Larval development of a molpadiid holothuroid, Molpadia intermedia (Ludwig, 1894) (Echinodermata)

摘要: Large adults of the caudate molpadiid Molpadia intermedia were collected from soft mud at depths 26–28 m in East Sound, Orcas Island, Washington. In early December, both sexes spawned laboratory: males released occasional puffs sperm and one female forcefully jetted eggs into water column. The egg is 267 ± 12 μm diameter negatively buoyant with an orangish pink yolky cap animal pole which, after fertilization, develops a coeloblastula through equal, holoblastic cleavages. doliolaria larva bears two posterior ciliary rings uniformly ciliated on anterior third its body. takes up benthic existence soon formation becomes pentactula protrusion five primary tentacles. Addition fine to cultures induced metamorphosis, which time collar yolk seen be transferred region digestive tract. larvae can delay metamorphosis for least 5 d absence mud. e...