Gamete spawning in Antipathella subpinnata (Anthozoa, Antipatharia): a structural and ultrastructural investigation

• Published in: Zoomorphology 2010-12, Vol.129 (4), p.213-219
• Main Authors: Gaino, Elda, Scoccia, Francesca
• Format: Article
• Language: English
• Subjects: Animal Anatomy; Animal Systematics/Taxonomy/Biogeography; Antipathella subpinnata; Biomedical and Life Sciences; Colonies; Corals; Cysts; Developmental Biology; Evolutionary Biology; Females; Fertility; Gametes; Histology; Life Sciences; Morphology; Organizations; Original Paper; Ova; Pharynx; Polyps; Polyps (organisms); Septum; Spawning; Sperm; Spermatozoa; Tentacles; Tissue; Tropical climate
• ISSN: 0720-213X; 1432-234X
• DOI: 10.1007/s00435-010-0112-x

Black coral colonies belonging to Antipathella subpinnata (Myriopathidae), found in Adriatic Sea (off the Tremiti Islands) and in Tyrrhenian Sea (Mezzo Canale), were inspected with the aim of investigating their reproductive activity. The small colony (about 42 cm tall) from Adriatic Sea was sexually immature, whereas the larger (about 120 cm tall) five colonies from Tyrrhenian Sea were fertile. Four colonies were males and one was a female, thus confirming the gonochoric condition already known for the black coral. Semithin sections proved that most of the egg and sperm masses flow out through the pharynx, even though small gamete masses were also observed emerging from the tentacles. In the female polyps, egg masses were enveloped by parental tissue derived from the breakage of the mesenterial septa, as observed in the male polyps for the sperm cysts masses. Ultrastructural observations provided details on the characteristics of egg and sperm in this taxon. Sperm stood out for the presence of an acrosome-like structure derived from the merging of pro-acrosomal vesicles. On the whole, the fine organization of the sperm recalled previous descriptions reported for some tropical black coral taxa.