Pelvic fins in Ophidion rochei are reduced to four rod-like structures situated at the ventral jaws. While the fish is swimming, they make continuous sweeping movements on the bottom. This paper examines and describes the anatomy of the pelvic fins to determine the possible functions of these appendages in relation to the mode of life of this fish species. The pelvic fins of O. rochei show strong similarities with barbels because they have identical sensory cell types, (taste buds, solitary chemosensory cells, and goblet cells), innervations and sensory function. Having nocturnal habits, specialization of pelvic fins in O. rochei corresponds to a supporting role to the life in dark environment. J. Morphol., 2012. © 2012 Wiley Periodicals, Inc.