Morphological plasticity of the Aden Nerite, Nerita adenensis Mienis, 1978 (Gastropoda: Cycloneritida: Neritidae)

Abstract

Fourteen morphotypes of the Aden nerite (Nerita adenensis) from Chabahar Bay, the northern Gulf of Oman, were sequenced for mitochondrial cytochrome c oxidase I and nuclear ATPSα genes. COI sequences across all morphotypes yielded uncorrected intraspecific genetic distances (p) of between 0.013 and 0.017, whereas interspecific p was 0.11–0.16 among congeneric species. For ATPSα, across all morphotypes, p was 0.00–0.03, whereas between N. adenensis and congeneric species, p was 0.07–0.19. Morphological analysis revealed a high degree of plasticity in shell colour, pattern and structure, while characters of the operculum and crenulations on the outer lip were more stable. Our descriptions provided here will be helpful in identifying this problematic taxon, which our genetic analyses show is best regarded as a single variable biological species.