Dynamique d'une population de Perinereis cultrifera (Gruebe) de la côte nord Bretagne = Population dynamics of Perinereis cultrifera on the north coast of Brittany
Scaps, P.; Retière, Ch.; Desrosiers, G.; Miron, G. (1992). Dynamique d'une population de Perinereis cultrifera (Gruebe) de la côte nord Bretagne = Population dynamics of Perinereis cultrifera on the north coast of Brittany. Cah. Biol. Mar. 33(4): 477-494
In: Cahiers de Biologie Marine. Station Biologique de Roscoff: Paris. ISSN 0007-9723; e-ISSN 2262-3094, more
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| Authors | | Top |
- Scaps, P.
- Retière, Ch.
- Desrosiers, G.
- Miron, G.
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| Abstract |
On the north coast of Brittany, Perinereis cultrifera has a 3-years life cycle. Some individuals, however may reproduce in their fourth year. Reproduction (with epitoke stages) takes place in late March or early April. Growth, initially segmentary, becomes ponderal in the second year of life. Sexual differentiation, which is also noticed in that time, starts in December for females or February-March for males. The third year is highlighted by processes related to reproduction; in March, individuals are completely epitoke: females and males are respectively emerald green and white and may contain up to 130 000 oocytes and 16,3 billions of spermatozoa. While growing, many individuals migrate from the upper to the lower level of the Fucus serratus zone occupying a thickening sedimentary stratum; in reproduction period, individuals execute a swarming migration in the opposite direction. Comparison between our data and those obtained from other studies in different sites of Perinereis culttifera's distribution illustrate a high plasticity in regard to reproduction and a high growth variability within the natural habitat. |
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