Hypleurochilus bananensis (Poll, 1959) (Pisces, Blenniidae) in Italian seas: distribution, habitat preference and sexual dimorphism

Hypleurochilus bananensis is one of the rarest species of Blenniidae in the Mediterranean Sea. Only few records have been made in the whole Basin. Due to its rarity, H. bananensis is poorly studied and little is known about its biology. In this study, we provide additional data on this rare species. In particular, we describe its habitat, sexual dimorphism, presence and distribution with several new records in both Tyrrhenian and Ionian Sea. Studies were conducted in the period from 2011 to 2014. Observations were carried out both by snorkelling and SCUBA diving. In the natural environment, we observed the behavior and coloration in both sexes. For two mature sampled specimens of both sexes, we examined the morphology, providing the first detailed information about the differences between them. Sexual dimorphism is very pronounced and past descriptions of this species were based only on female specimens. This could lead to misidentification cases. Indeed, especially the morphology and chromatic pattern of the male are similar to those of other combtooth blennies species. Furthermore, we report data about reproduction, habitat preference and consideration about its presence in Italian seas.