Kide, N. G., Dunz, A., Agnese, J. - F., Dilyte, J., Pariselle, A., Carneiro, C., et al. (2016). Cichlids of the Banc d'Arguin National Park, Mauritania: insight into the diversity of the genus Coptodon. J. Fish Biol., 88(4), 1369–1393.
Résumé: To determine the species diversity of cichlids in the Banc d'Arguin National Park (PNBA) and their phylogenetic relationships with other species in West Africa, a morphometric and meristic and molecular phylogenetic study was conducted. Both approaches not only confirm the presence of Sarotherodon melanotheron in PNBA but also demonstrate the presence of a second species from the genus Coptodon. While morphometric characteristics match the description of the Guinean tilapia Coptodon guineensis, phylogenetic reconstructions based on three mitochondrial and one nuclear DNA fragment demonstrate that C. guineensis is paraphyletic over its range. Because different lineages of C. guineensis are allopatric, the distribution of C. guineensis should be restricted to Ghana and Cote d'Ivoire. The many other lineages of this species should be considered as C. sp. aff. guineensis. (C) 2016 The Fisheries Society of the British Isles
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Lorin-Nebel, C., Avarre, J. C., Faivre, N., Wallon, S., Charmantier, G., & Durand, J. D. (2012). Osmoregulatory strategies in natural populations of the black-chinned tilapia Sarotherodon melanotheron exposed to extreme salinities in West African estuaries. J. Comp. Physiol. B-Biochem. Syst. Environ. Physiol., 182(6), 771–780.
Résumé: The effect of salinity was studied in natural populations of the black-chinned tilapia (Sarotherodon melanotheron) from West Africa. This euryhaline species colonizes nearly all coastal environments from bays to lagoons characterized by salinities ranging from fresh water to hypersaline water over 100 aEuro degrees. Individuals were sampled during the dry season at several locations characterized by different levels of salinity (3-102 aEuro degrees). Their osmotic status and their gills were analyzed. The branchial mitochondria-rich cells (MRC), localized at the basis of the filaments and along the lamellae in fish taken from the saline stations, showed a wide plasticity with significant differences in their number and size. The most striking results were a significant larger area (a parts per thousand 3x) and a higher number (a parts per thousand 55x) of MRC at high salinity (102 aEuro degrees) compared to low salinity (3 aEuro degrees). The major ion transporters and channels were localized by immunocytochemistry and different expression patterns have been recorded between stations. Despite an increased Na+/K+-ATPase (NKA) alpha-subunit expression and NKA activity, pointing to an increased monovalent ion excretion, a severe osmotic imbalance was recorded in animals living in hypersaline environments.
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