Intraspecific variation in the shell ornamentation of benthic Ostracoda (Crustacea) from Kiribati, Pacific Ocean

Abstract

Twenty four species of ostracod have been found on Tarawa Atoll and fifteen on Kuria Island, Republic of Kiribati in the western Pacific Ocean. Thirteen species are common to both atolls. A consistent difference has been discovered in the ostracod faunas of Tarawa and Kuria, with those from Kuria showing coarser texture in the ornamentation than their counterparts from Tarawa. The variation of carapace ornamentation has led to multiple names for a species. A characteristic ornamentation at a particular locality may be a due to a small number of specimens colonising the new locality and having a limited gene pool. Alternatively, any variation in the ornamentation may be a clue to multiple phases of colonisation within a small area.