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Françoise Denis

  • Biodiversity Journal, 13 (3): 0695-0706

    Hiba Rezzag Mahcene, Mohamed Said Ramdani, Abdelhak Sebbih, Tarik Meziane, Françoise Denis, Ouided Maamcha, Patrick Georges Thiery Moanono & Tarek Daas
    Diversity of benthic macroinvertebrates in the Algerian East Coast
    https://doi.org/10.31396/Biodiv.Jour.2022.13.3.695.706

    ABSTRACT
    Marine biodiversity play a fundamental role in the ecology and functioning of benthic communities. The study of the structure of benthic macroinvertebrate peoples is an excellent tool for evaluating the impact of human activities on the ecological quality of lotic environments. However, little data is available on the diversity, structure and ecology of benthic macroinvertebrates of the Algerian east coast. The main purpose of this work is to present an inventory of the current faunistic data general at three sites of study in Algerian east coastline: El-Kala, Annaba and Skikda. After doing the morphometric analysis of all the individuals, this study allowed to the identification of several species of macroinvertebrates. The variations in the distribution of these macroinvertebrates at different sites are related to external factors (temperature, salinity, dissolved O2), that would have an impact on the abundance of the species of marine fauna of the Algerian east coastline.

  • Biodiversity Journal, 11 (2): 505-526

    Mohamed S. Ramdani, Hiba Rezzag Mahcene, O. Daas-Maamcha, Tarek Daas & Françoise Denis
    Effects of environmental stress on the growth and the reproduction of Perinereis cultrifera (Annelida Polychaeta) from the eastern coasts of Algeria
    https://doi.org/10.31396/Biodiv.Jour.2020.11.2.505.526

    ABSTRACT
    Polychaetes tend to form the dominant sediment dwelling fauna of the most mudflats, estuaries and sheltered sandy shores and it also play a significant role in ecosystem functioning and services. Seasonal changes in the length, fresh weight, oocyte diameter, sexual status and sexual maturity index of the polychaete Perinereis cultrifera (Grube, 1840) (Anellida Polychaeta Nereididae) were studied during twelve months from January to December 2016 in the east coast of Algeria. The samples were collected monthly at three sites: El-Kala, a site far from any source of pollution, Annaba and Skikda, sites located near human and industrial wastes. The reproductive cycle of the females was studied; however, the ovaries consist of coelomic germ-cell clusters surrounded by a thin envelope of follicle cells. The female coelomic puncture has a heterogeneous aspect and shows different oocyte diameters. The reproductive period is more intense in spring period. The results show differences between sites compared with the reference samples. The reproduction period of occurs in spring (April, May). This approach confirms that individuals collected from Annaba and Skikda have been submitted to a highly polluted environment. Therefore, individuals sampled from Skikda showed the highest reduction of different measured parameters.