The study of diet examined 272 specimens of Sphyrna zygeana (162 males and 110 females) and 215 specimens of Isurus oxyrinchus (120 males and 95 females) from artisanal fisheries. They were collected between October 2009 and September 2010. The analysis of stomach contents revealed that 87estomacs Sphyrna zygeana were empty (31.98%) and 185 stomachs contained food (262 prey). 154 stomachs of Isurus oxyrinchus contained food (224 prey) and 61 stomachs were empty (28.37%). According to the index of relative importance (IRI) calculated both diets consisted mainly of fish. Levin's Index obtained from S. zygeana (Bi = 0.446) and I. oxyrinchus (Bi = 0.432) indicates that trophic niche is relatively narrow. These two species are specialist predators that use fewer resources with a preference for fish. The community index of Jaccard (Sj = 0.265 <0.5) indicates a similarity between the diet of both species. There is also a dietary overlap (? = 0.7644) between these two species and gender (I. oxyrinchus, C? = 0.897 and S. zygeana, C? = 0.868).
The dynamics of the exploited population of Istiophorus albicans (Atlantic sailfish) from artisanal gillnet fishery was investigated based on length frequency data, using FiSAT software. Specimens were sampled from the artisanal fishery captures in the coastal waters near Abidjan (C
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