Infestation, population dynamics, growth and reproductive cycle of Myzostoma cirriferum (Myzostomida), an obligate symbiont of the comatulid crinoid Antedon bifida (Crinoidea, Echinodermata)
Eeckhaut, I.; Jangoux, M. (1997). Infestation, population dynamics, growth and reproductive cycle of Myzostoma cirriferum (Myzostomida), an obligate symbiont of the comatulid crinoid Antedon bifida (Crinoidea, Echinodermata). Cah. Biol. Mar. 38(1): 7-18
In: Cahiers de Biologie Marine. Station Biologique de Roscoff: Paris. ISSN 0007-9723; e-ISSN 2262-3094, meer
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| Abstract |
The population dynamics of the symbiont Myzostoma cirriferum and the dynamics of infestation of its host Antedon bifida were investigated at Morgat (Brittany, France) over a 5-year period. The larger the host, the greater the infestation. The infestation varies according to the season: it is at maximum in winter, decreases in spring, and becomes stabilized at a low level from summer to the next winter. The huge infestation in winter is due to the recruitment of young individuals into the population of M. cirriferum. That recruitment is independent of myzostome reproductive activity (ovarian maturity, spermatophoral emissions, and egg layings are steady throughout the year), but may be linked to an increase in the comatulid feeding activity: in feeding more, comatulids can catch more infestive-stage myzostome larvae. In spring, the infestation falls, which may be due to both the myzostomes' natural mortality and the appearance of amphipods on the hosts which may act as predators. From summer to the next winter, infestation stays stable, which can be explained by the equilibrium existing between the natural mortality of the myzostomes and their continuous reproduction. The longevity of M. cirriferum is estimated to be ca 6 months. |
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