Mémoire
| Résumé : | Populations of Clownfish species often show signs of local isolation due limited dispersal potential and sea surface currents. On top of that, anthropogenic pressure such as overharvesting and reef exploitation triggers them from reduced population size, eventually leading to local extinction. The understanding of the genetic population structure, as well as the influence of both historical lineages and current connectivity, is required to design effective conservation plans and properly protect these species. In this study, the genetic structure of Clark's Anemonefish (Amphiprion clarkii) populations of the Indo-Malay Archipelago (IMA) is assessed through genetic markers. Demographic quantities such as gene flow, population effective size and divergence time were also estimated for four Amphiprion species. Results provided evidence of a clear genetic structure (mtCR: (I)st = 0.42039, P < 0.0001; microsatellites: Fst = 0.01449, P < 0.0001) and best supported regional groupings ( (I)ct = 0.63852 Fct = 0.05199).Overall, genetic breaks were identified among Western (Padang Karimunjawa), Central (Sulawesi, Borneo, Bali, Komodo, Timor), and Eastern IMA (Biak) populations, which matches with patterns obtained for congeneric species. Population divergence time estimates also showed that populations of all Amphiprion species studied diverged during the last glaciation event of the Pleistocene, suggesting that these breaks are 50k years old in average. This study provides information that should be taken into account while designing Marine Protected Areas. |
