Reproductive cycles and recruitment in Ophiomastix venosa and Ophiocoma scolopendrina, two co-existing tropical ophiuroids from the barrier reef of Toliara (Madagascar)
Delroisse, J.; Fourgon, D.; Eeckhaut, I. (2013). Reproductive cycles and recruitment in Ophiomastix venosa and Ophiocoma scolopendrina, two co-existing tropical ophiuroids from the barrier reef of Toliara (Madagascar). Cah. Biol. Mar. 54(4): 593-603 In: Cahiers de Biologie Marine. Station Biologique de Roscoff: Paris. ISSN 0007-9723; e-ISSN 2262-3094, more | |
Keywords | Echinodermata [WoRMS]; Ophiuroidea [WoRMS] Marine/Coastal | Author keywords | Reproduction; Echinodermata; Ophiuroid; Reef ecology; Intertidal ecology |
Abstract | The reproductive cycles and recruitment of two co-existing ophiuroids species, Ophiocoma scolopendrina and Ophiomastix venosa, were investigated on the barrier reef of Toliara (Madagascar) from February 2000 to April 2001. The two species inhabit the boulder tract of the barrier reef. O. scolopendrina reproduces continuously, has planktotrophic larvae, and new recruits are seen year-round while O. venosa has a clear annual reproductive cycle. In the latter, spawning occurs during the austral summer (from November to February), larvae are lecithotrophic, and new recruits (individuals less than 4 mm disk diameter) were seen mostly from February to May. It is hypothesized that differences in reproductive strategies shown by the two species are linked to local environmental conditions and species adaptations. The tolerance to emersion shown by O. scolopendrina allows it to successfully colonize regularly emerged areas. As for O. venosa, while adults live in permanently immersed tidal channels, juveniles were often seen as symbiont of O. scolopendrina, which allows them both to resist emersion and to increase the species recruitment area. |
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