Quick Definition
The paired intromittent organs of male elasmobranchs (sharks and rays), formed from the inner edge of the pelvic fins, used to deliver sperm during internal fertilisation.
📖 Full Definition
Claspers are the copulatory organs of male elasmobranchs. They are formed from the elongated, calcified inner portion of the pelvic fin, with each male possessing a pair. During mating the male inserts one clasper into the female's cloaca. A muscular siphon sac under the skin of the pelvic fin pumps seawater or seminal fluid through the clasper to facilitate sperm transfer. Clasper morphology is species-specific and used in elasmobranch taxonomy.