A new species of holothuroid from the Labrador Sea (eastern Canada): Pseudothyone labradorensis sp. nov. (Echinodermata, Holothuroidea, Dendrochirotida, Sclerodactylidae)

By

Kremenetskaia, Antonina
Alvestad, Tom
Penney, Heather
Hamel, Jean-François
De Moura Neves, Bárbara
Cote, David
Mercier, Annie

Type

Article

Date of Publication

2024

Original Publication

ZooKeys

Volume

1206

Pages

191--206

Subjects

Bathyal fauna , Distribution , Northwest Atlantic fauna , Sea cucumbers , taxonomy

Contributed by

Pensoft Publishers

Language

English

Published by

Sofia, Bulgaria Pensoft Publishers

Identifiers

DOI: https://doi.org/10.3897/zookeys.1206.123364

 

Abstract

A new species of holothuroid, Pseudothyone labradorensissp. nov. (order Dendrochirotida and family Sclerodactylidae), was discovered off the coast of Labrador (eastern Canada) at a depth of 740–969 m. Two specimens were described based on morphological and genetic parameters. Distinctive characters included pinkish body colour, presence of tube feet on a ‘tail’, supporting rod-shaped ossicles in the tube feet, and rod-shaped ossicles in the tentacles. To investigate its phylogenetic relationships, partial sequences of COI were obtained for the new species as well as for the type species P. raphanus and another North Atlantic species P. serrifera. According to the phylogenetic analysis, P. labradorensissp. nov. appeared in a well-supported clade with P. raphanus and P. serrifera. Molecular data also suggest polyphyly of the genus, showing the Northeast Pacific species Pseudothyone belli recovered outside of the clade containing the type species. Pseudothyone labradorensissp. nov. is the first species of the genus from the Northwest Atlantic. A key to the North Atlantic Pseudothyone is provided.