Description of a new Osedax (Annelida, Polychaeta, Siboglinidae) species colonizing cow bones in the South Atlantic Ocean

By

Gularte, Thammy
Sumida, Paulo Yukio Gomes
Bergamo, Gilberto
Rouse, Greg W

Type

Article

Date of Publication

2024

Original Publication

ZooKeys

Volume

1219

Pages

215--231

Subjects

new species , Phylogeny , taxonomy , whale falls

Contributed by

Pensoft Publishers

Language

English

Published by

Sofia, Bulgaria Pensoft Publishers

Identifiers

DOI: https://doi.org/10.3897/zookeys.1219.134005

 

Abstract

A new species of Osedax is described here using molecular and morphological data. It was found at the depth of 550 m off the Brazilian coast through experimental deployment of cow bones. Osedax nataliaesp. nov. is the second Osedax species from the Southwest Atlantic Ocean and had been previously reported as Osedax ‘BioSuOr-4’. Phylogenetic analysis of five concatenated genetic makers (28S rDNA, Histone H3, 18S rDNA, 16S rDNA, and cytochrome c oxidase I) placed Osedax nataliaesp. nov. within a well-supported Osedax Clade V, nested within a clade of Pacific Ocean Osedax though with poor support. The minimum interspecific COI distance between O. nataliaesp. nov. and another known Osedax was 13.92% (closest to O. ‘sagami-3’). The maximum intraspecific COI diversity (uncorrected) within O. nataliaesp. nov. sampled here was 2.44% and population structure was visualized via haplotype network analysis. Morphologically, O. nataliaesp. nov. is characterized by its reddish orange crown of palps and a ventral yellowish collar on the anterior trunk where it meets the base of the crown. Osedax nataliaesp. nov. shares features with other Clade V species, notably pinnules inserted on the outer margin of palps. Additionally, the presence of dwarf males within the tube lumen of females was documented. Further sampling and research in the Southern Hemisphere are needed to understand the diversity and biogeography of Osedax across the world’s oceans.