The Striped Dolphin is an oceanic species. Current population trend is unknown, although the population may have recovered to pre-1990 levels, at least in some areas (Gómez de Segura et al. The population declined in the early 1990s. This appears to be confirmed by significant differences in tissue pollutant levels between Spain and Italy (Monaci et al. Moreover, inside the Mediterranean there is some clinal variation in body size suggestive of population structure and/or restriction in gene flow between areas (Calzada and Aguilar 1995). On a smaller geographic level, Gaspari (2004) found evidence of genetic differentiation between inshore and offshore populations in the Ligurian Sea. Furthermore, there is evidence for sex-biased dispersal (Gaspari et al. Genetic analyses of Striped Dolphins from Gibraltar to the coast of Israel, both at nuclear and mitochondrial levels, show that this species is genetically structured within the Mediterranean with low gene flow across the basin. Mitochondrial DNA analysis, from Gibraltar to Greece, yielded 59 haplotypes (n=166), none of which was shared between the two areas, thus supporting strong differentiation analyses of nuclear DNA support this result (Gaspari et al. Skull size is also smaller in Mediterranean specimens than in their neighbouring Atlantic counterparts (Archer 1997). Maximum body length of eastern North Atlantic striped dolphins is 5-8 cm longer than that of Mediterranean individuals (Calzada and Aguilar 1995). Morphological and genetic studies strongly suggest that the Mediterranean and eastern North Atlantic populations are genetically differentiated, with little or no gene flow across the Straits of Gibraltar. It is present throughout the Mediterranean Sea but has not been recorded in the Black Sea. This species occurs in temperate and subtropical waters of all oceans. Red List Category & Criteria: Vulnerable A2bcde
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |