FIRST CASE OF IMPOSEX IN NEPTUNEA CONVEXA (GASTROPODA: BUCCINIDAE) FROM BATHYAL DEPTHS (SEA OF OKHOTSK, >1400 M)

Owing to its worldwide use as an anti-fouling agent, tributyltin (TBT) is a common contaminant of marine ecosystems. Its wide distribution, high hydrophobicity and persistence have raised concern about bioaccumulation, potential biomagnifications in food webs, and adverse effects on the environment and human health. The most frequent and acute effect of TBT is found in gastropods, usually living in shallow waters, rarely at depths more than 100 m. This study reports about the first case of imposex in a deep water buccinid whelk Neptunea convexa collected at 1437 m in the Sea of Okhotsk. Among five collected specimens, the two were imposex females at the 1st stage of imposex development, while the rest three were males with normally developed penises. Most probably, TBT entered the whelk’s body by eaten benthic organisms, which feed on detritus with traces of TBT, but other reasons, such as heavy metal pollution, are also discussed.