|Dynamique et reproduction de Nephtys hombergii (annélide polychète) dans le Bassin d'Arcachon = Population dynamics and reproduction of Nephtys hombergii (Annelida Polychaeta) in the Arcachon Basin|
Mathivat-Lallier, M.-H.; Cazaux, Cl. (1989). Dynamique et reproduction de Nephtys hombergii (annélide polychète) dans le Bassin d'Arcachon = Population dynamics and reproduction of Nephtys hombergii (Annelida Polychaeta) in the Arcachon Basin. Cah. Biol. Mar. 30(4): 473-486
In: Cahiers de Biologie Marine. Station Biologique de Roscoff: Paris. ISSN 0007-9723, more
|Authors|| || Top |
- Mathivat-Lallier, M.-H.
- Cazaux, Cl.
Four intertidal populations of Nephtys homergii have been sampled from the Bay of Arcachon (France) for observations on their population structure, reproductive cycle and species recruitment. The settled populations, more dense near the oceanic than inland area of the Bay, comprise five generations, the first appearing in June-July, and subsequently at different time intervals depending on the station. The mean diameter of the oocytes reveals the degree of female maturation, while sudden periodic decreases in size were considered to indicate spawning phases. The last unspawned oocytes are resorbed. Two principal spawning phases, asynchronised between the stations, take place during the reproductive cycle. They are followed by the recruitment of two successive cohorts of juveniles whose settlement is staggered temporally from one station to another. The second cohort is always the more numerous. This study shows that the total duration of species reproduction and recruitment within a confined area like the Arcachon Bay is due to an asynchronous oogenesis in different spatially-separate populations.