amplexus

Amplexus is a mating embrace used by many amphibians during reproduction. In this behavior, the male grasps the female with his forelimbs and remains attached as eggs are fertilized. The grasp positions vary among taxa and are used in species identification.

The main forms described in frogs and toads are axillary amplexus, where the male clasps around the female's body just behind the forelimbs, and inguinal amplexus, where the grasp occurs around the hips. Less common variants include cephalic amplexus around the head and other region-specific grasings. In salamanders, amplexus is commonly axillary but can differ by family; in many species fertilization is internal, with the male delivering a spermatophore that the female takes into her cloaca, while in most frogs and toads fertilization is external: eggs are released by the female into water and sperm deposited by the male fertilizes them.

The behavior serves to position the female for egg release, increase the likelihood of fertilization, and reduce the chance the female detaches before mating is complete. The duration and form of amplexus are influenced by species, habitat, and reproductive strategy, and are often used in taxonomic descriptions.

The term amplexus comes from Latin amplexus, meaning embrace.