%0 Journal Article
%9 ACL : Articles dans des revues avec comité de lecture répertoriées par l'AERES
%A Diouf, Khady
%A Panfili, Jacques
%A Labonne, Maylis
%A Aliaume, C.
%A Tomas, J.
%A Chi, T. D.
%T Effects of salinity on strontium : calcium ratios in the otoliths of the West African black-chinned tilapia Sarotherodon melanotheron in a hypersaline estuary
%D 2006
%L PAR00001090
%G ENG
%J Environmental Biology of Fishes
%@ 0378-1909
%K Cichlidae ; life history ; behaviour ; otolith microchemistry
%K SENEGAL
%K SINE SALOUM
%M CC:0002397411-0002
%N 1
%P 9-20
%R 10.1007/s10641-006-9048-x
%U https://www.documentation.ird.fr/hor/PAR00001090
%> https://www.documentation.ird.fr/intranet/publi/2006/09/010035743.pdf
%V 77
%W Horizon (IRD)
%X The biology and the behaviour of fish populations in hypersaline environments are poorly known. The habitat occupation strategy of the tilapia Sarotherodon melanotheron has been studied along a salinity gradient in the Saloum hypersaline estuary in Senegal ( salinity between 32 and 100). The individual migratory behaviour has been analysed from otolith strontium-to-calcium concentration ratios from fish sampled in five locations during the 2003 wet season and the 2004 dry season. In the upper part of the estuary ( salinities > 50), the Sr: Ca ratio in the otolith showed high variations, from 2.51 to 33.30 x 10(-3). These maximum observed values have never been reported in the literature. The individual mean of Sr: Ca ratios increased according to the salinity gradient in the estuary, with significantly higher values in the upper part ( Sr: Ca mean = 16 x 10(-3)) than in the lower part ( salinity < 50, Sr: Ca mean = 12 x 10(-3)). No significant difference in the Sr: Ca mean was observed between locations with comparable salinities. Sr concentration in the water at the different locations was positively correlated with ambient salinity. The mean of Sr: Ca in the otoliths was then in relationship with the level of Sr in the water. Thus, the Sr: Ca ratios in the otolith of S. melanotheron allowed to discriminate the populations of this species and to hypothesize that they did not undertake large scale movements within the estuary.
%$ 036