The cephalic clasper (tentaculum) is a unique, club-like organ not found in any other vertebrates. The cephalic clasper is located on the head of the fish, just anterior to the eyes. The tip of the retractable organ is fleshy and lined with numerous small, sharp barbs. For the male to stay attached during courtship, the clasper has been observed to clamp down on the pectoral fin of the female. Additional evidence for this use has been found in the form of scars and scratches on the dorsal sides of females. The significantly smaller body size of males, which is a sexually dimorphic characteristic, may be a contributing factor to this mating behavior.