01772nas a2200181   4500008004100000245014700041210006900188300001200257490000700269520113800276653003301414100001601447700001901463700002501482700002001507700001901527856004401546       2011                        eng d00aReproduction, population dynamics and production of Nereis falsa (Nereididae: Polychaeta) on the rocky coast of El Kala National Park, Algeria0 aReproduction population dynamics and production of Nereis falsa   a165-1730 v653 aThe polychaete Nereis falsa Quatrefages, 1866 is present in the area of El Kala National Park on the East coast of Algeria. Field investigations were carried out from January to December 2007 to characterize the populations’ reproductive cycle, secondary production and dynamics. Reproduction followed the atokous type, and spawning occured from mid-June to the end of August/early September when sea temperature was highest (20–23°C). The diameter of mature oocytes was approximately 180 μm. Mean lifespan was estimated to about one year. In 2007, the mean density was 11.27 ind. m -2 with a minimum of 7.83 ind. m -2 in April and a maximum of 14.5 ind. m -2 in February. The mean annual biomass was 1.36 g m -2 (fresh weight) with a minimum of 0.86 g m -2 in December and a maximum of 2.00 g m -2 in June. The population consisted of two cohorts distinguishable from size frequency distributions. One cohort corresponded to the recruitment of 2006 and the other appeared during the study period in September 2007. The annual production of N. falsa was 1.45 g m -2 year -1 , and the production/biomass ratio was 1.07 year -1 .10aBiomedical and Life Sciences1 aDaas, Tarek1 aYounsi, Mourad1 aDaas-Maamcha, Ouided1 aGillet, Patrick1 aScaps, Patrick  uhttps://annelida.myspecies.info/node/10