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Reproductive Anatomy
Claspers (Sharks & Rays)
Myxopterygia
Paired grooved appendages on male sharks and rays, modified from the inner pelvic fin edges, used to deliver sperm during internal fertilisation.
Region: Tail Externally visible Unique to: cartilaginous
📖 Overview
Claspers are the reason cartilaginous fish do internal fertilisation while most bony fish spawn externally. A male shark inserts one clasper into the female cloaca, and sperm flows down a groove on the clasper into her reproductive tract. Presence of claspers is the primary field-identification of shark sex.
🧬 Structure
Rod-like extensions of the pelvic fin skeleton, grooved along their inner surface. Calcified in mature males, cartilaginous in juveniles.
⚙️ Function
Sperm delivery during copulation; often equipped with hooks and spurs to maintain position during mating.
✨ Fun Fact
Clasper calcification is the standard shark maturity indicator - fisheries biologists check clasper rigidity to distinguish adult from juvenile males in the field.
🔗 Related Reproductive Structures