myxopterygium

(plural myxopterygia))

the copulatory organ or clasper of Elasmobranchii and Holocephali; rod-like extensions of the inner side of the pelvic fins. It is composed of the long stem cartilage, a shorter distal cartilage, the dorsal terminal cartilage (or rhipidion, fan-shaped for dispersing sperm in a radiating spray during copulation), the hook-shaped terminal cartilage (or claw) which has a cutting edge on its inner margin, and the narrow, sharp spur. The claw and spur serve to anchor the clasper in the female oviduct and a groove along the clasper enables the sperm to reach the oviduct. The siphon contracts to propel sperm into the oviduct. See also tenaculum