02225nas a2200241 4500008004100000245013000041210006900171260000900240300001200249490000700261520147900268653001101747653001301758653001501771653004201786653001901828653002401847653001701871100001401888700001701902700001801919856004601937 2000 eng d00aMorphological and allozyme variation of Eidolon helvum (Mammalia: Megachiroptera) in the islands of the Gulf of Guinea0 aMorphological and allozyme variation of iEidolon helvum iMammali c2000 a359-3780 v713 aMorphological and genetic variation is evaluated among populations of the bat, Eidolon helvum, in the islands of the Gulf of Guinea (Central Africa). The populations from the islands of Bioko, Principe, and Sao Tome do not show significant phenetic differentiation, although a trend towards a reduction of size is found in the latter two islands. The low genetic distances between populations, as well as their values of Wright’s fixation indexes, suggest that gene flow has hampered differentiation on these islands. In contrast, the population from Annobon, the smallest and farthermost island, shows remarkable morphological and genetic differentiation. On the mainland, E. helvum displays unique migratory and dispersal behaviours, but migratory behaviour was not found in any of the island populations. The combination of selective forces in harsher oceanic environments and restricted gene flow among populations appears to have favoured the high degree of morphological differentiation of E. helvum on Annobon. Due to the extended length of the dry season in Annobon, an earlier achievement of sexual maturity-and consequently smaller size-may be advantageous in the absence of migration. The differentiation is more marked among females, which also suggests that selection may be linked to the reproductive pattern. The population of the island of Annobon is herein described as a new subspecies, Eidolon helvum annobonensis subsp. nov.10aAfrica10aAnnobón10aChiroptera10aEidolon helvum annobonensis ssp. nov.10aGulf of Guinea10aisland biogeography10aPteropodidae1 aB., Juste1 aIbáñez, C.1 aMachordom, A. uhttps://afribats.myspecies.info/node/4200