Sexual reproduction of Hippospongia communis (Lamarck, 1814) (Dictyoceratida, Demospongiae): comparison of two populations living under contrasting environmental conditions

Authors

  • Souad Zarrouk,

    1. Institut National des Sciences et Technologies de la Mer, Salammbô, Tunisia
    2. Faculté des Sciences Mathématiques, Physiques et Naturelles de Tunis, Compus Universitaire Tunis El Manar, Université de Tunis El-Manar, Tunis, Tunisia
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  • Alexander V. Ereskovsky,

    1. CNRS UMR 7263 IMBE ‘Institut Méditerranéen de Biodiversité et d'Ecologie marine et continentale’, Station marine d'Endoume, Aix-Marseille Université, Marseille, France
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  • Karim Ben Mustapha,

    1. Institut National des Sciences et Technologies de la Mer, Salammbô, Tunisia
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  • Amor El Abed,

    1. Faculté des Sciences Mathématiques, Physiques et Naturelles de Tunis, Compus Universitaire Tunis El Manar, Université de Tunis El-Manar, Tunis, Tunisia
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  • Thierry Pérez

    Corresponding author
    1. CNRS UMR 7263 IMBE ‘Institut Méditerranéen de Biodiversité et d'Ecologie marine et continentale’, Station marine d'Endoume, Aix-Marseille Université, Marseille, France
    • Correspondence

      Thierry Pérez, Aix-Marseille Université, CNRS UMR 7263 IMBE ‘Institut Méditerranéen de Biodiversité et d'Ecologie marine et continentale’, Station marine d'Endoume, rue de la Batterie des Lions, 13007-Marseille, France.

      E-mail: thierry.perez@imbe.fr

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Abstract

The study of the reproductive processes of benthic invertebrates is essential to the understanding of their population dynamics and is also important in formulating conservation plans, especially for exploited species. The sexual reproduction of Hippospongia communis, the ‘honeycomb’ bath sponge, was studied at two locations in the Mediterranean Sea: the Kerkennah Islands (Tunisia, South Mediterranean), where the mean annual seawater temperature is 19 °C, and Marseille (France, Northwestern Mediterranean Sea), where the mean annual water temperature is 16 °C. The aim of this comparative study was to determine whether different environmental conditions could affect reproduction patterns. At both locations, H. communis was found to contain sexual reproductive elements year-round. Oogenesis and embryogenesis occurred throughout the year, whereas spermatogenesis occurred during shorter periods between October and November, in both populations. While gametogenesis seemed to be synchronized, indicating that fertilization could occur at the same time at both locations, spawning was observed in late summer in Marseille, whereas it started in late spring for the Kerkennah population. Larval development of H. communis seems to take longer for sponges living at cooler locations such as Marseille. Reproductive effort calculated for both sexes showed significantly higher values for specimens from Kerkennah Islands. By comparing sexual reproductive patterns of populations living in two contrasted environments, we suggest that a change of thermal regime can affect H. communis phenology.

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