The ancient and helical architecture of Elasmobranchii's spermatozoa enables progressive motility in viscous environments.

ABSTRACT: Subclass Elasmobranchii belongs to an old evolutionary class of Chondrichthyes that diverged 450 mya, presenting a wide diversity of reproductive strategies while preserving the ancient mode of internal fertilization. Despite such evolutionary success, many species in this group are at serious risk of extinction. Understanding the principles of sperm progressive motility and physiology of such an ancient group of vertebrates is crucial for advancing future assisted reproductive techniques to safeguard this species and for deepening our understanding of the evolution of reproduction. Elasmobranchii species possess big spermatozoa (compared to bony fishes) with an elongated helical head and tail similar to one currently existing (but later diverged) in birds, reptiles, and amphibians, which

SUBMITTER: Boryshpolets S 

PROVIDER: S-EPMC11856307 | biostudies-literature | 2025

REPOSITORIES: biostudies-literature