Molecular phylogeny and taxonomy of the genus Pilumnus Leach, 1815 (Eucrustacea: Brachyura: Pilumnidae) in the Persian Gulf and Gulf of Oman

The genus Pilumnus covering a large group of bristle crabs, a typical resident of rocky, cobble and coral habitats. Taxonomy of the genus in the Persian Gulf and Gulf of Oman have always been source of disagreement among specialists due to potential taxonomic uncertainty in the genus. We used combined morphological and molecular characteristics to provide an insight into the real diversity within this genus. Partial fragment of two mitochondrial genes (COI and 16S rRNA) and one nuclear gene (H3) were used for molecular analyses. Both Bayesian and Maximum likelihood methods estimated a similar tree topology with highly supported clades. The tree showed the occurrence of two groups including the Atlantic and Indo-West Pacific species. Our result showed that there is a well consistency between morphological and molecular characteristics at interspecific level. Five species were identified from the Persian Gulf and Gulf of Oman, including P. incanus, P. longicornis, P. savignyi, P. persicus n. sp. and P. parvusi n. sp. Pilumnus persicus n. sp. is closely related to P. minutus, which has been already recorded from the region, but it is described here as a new species; according to current morphology and molecular data. Pilumnus parvusi n. sp. differed from the other congeners occurring in the Persian Gulf, whereas it is genetically presented as sister clade to the Atlantic species group . (c) 2020 Published by Elsevier GmbH.