Diversity of bone-eating Osedax worms on the deep Atlantic whale falls—bathymetric variation and inter-basin distributions

Abstract

Bone-eating Osedax worms can quickly colonize exposed bones and are important ecosystem engineers in whale fall communities, contributing to cause of bone degradation. This study shows that the deep SW Atlantic margin harbors many Osedax species. Using DNA barcoding, we found four putative new lineages as well as O. frankpressi Rouse, Goffredi, and Vrijenhoek, 2004 and O. braziliensis Fujiwara, Jimi, Sumida, Kawato, & Kitazato, 2019, with assemblages varying with depth. It is probable that the bathymetric distributions of these species are controlled by different water masses and their directions of flow. The haplotype network of Atlantic and Pacific O. frankpressi populations suggests segregation between populations, as is also seen in the high FST. However, the low p distance between both populations and the few substitution sites separating haplogroups from both regions (Atlantic and Pacific) could be evidence that populations of both basins are somehow close to each other. It is likely that whale fall habitats exist between both populations analyzed, connecting both basins.