Musculature development in planuloids of Cassiopeia xamachana (Cnidaria: Scyphozoa)

摘要: Polyps of the family Cassiopeidae (Cnidaria: Scyphozoa) can reproduce asexually by forming a ciliated swimming stage, planuloid. It is externally similar to planula larva and has traditionally been referred as planuloid bud. Using phalloidin labeling, we described development muscular system in planuloids Cassiopeia xamachana during growth metamorphosis into polyp. Early stages involve septal muscle bands polyp but after separation from mother organism it forms its own musculature de novo. Muscular elements newly separated are represented short disordered fibers four main groups longitudinal muscles. These primary future During further grows, changes shape elongated triangular starts form hypostome tentacles anlages. By time settlement bands. Process formation differs that scyphozoan planulae, which lack well-developed elements. The might be modification lateral budding, with daughter occurring distantly organism. could not called true buds because their independent growth, so term “planuloid bud” misleading. We argue best name for this stage since reflects biology at same emphasizes similarity larva.