A multiscale approach reveals elaborate circulatory system and intermittent heartbeat in velvet worms (Onychophora).

ABSTRACT: An antagonistic hemolymph-muscular system is essential for soft-bodied invertebrates. Many ecdysozoans (molting animals) possess neither a heart nor a vascular or circulatory system, whereas most arthropods exhibit a well-developed circulatory system. How did this system evolve and how was it subsequently modified in panarthropod lineages? As the closest relatives of arthropods and tardigrades, onychophorans (velvet worms) represent a key group for addressing this question. We therefore analyzed the entire circulatory system of the peripatopsid Euperipatoides rowelli and discovered a surprisingly elaborate organization. Our findings suggest that the last common ancestor of Onychophora and Arthropoda most likely possessed an open vascular system, a posteriorly closed heart with segmental os

SUBMITTER: Jahn H 

PROVIDER: S-EPMC10147947 | biostudies-literature | 2023 Apr

REPOSITORIES: biostudies-literature