Exploring the use of micro-computed tomography (micro-CT) in the taxonomy of sea cucumbers: a case-study on the gravel sea cucumber Neopentadactyla mixta (Östergren, 1898) (Echinodermata, Holothuroidea, Phyllophoridae)

By

Samyn, Yves
Sonet, Gontran
D'Udekem D'Acoz, Cedric

Type

Article

Date of Publication

2021

Original Publication

ZooKeys

Volume

1054

Pages

173--184

Subjects

integrative taxonomy , micro-CT , Normandy , Scanning electron microscopy

Contributed by

Pensoft Publishers

Language

English

Published by

Sofia, Bulgaria Pensoft Publishers

Identifiers

DOI: https://doi.org/10.3897/zookeys.1054.67088

 

Abstract

Sea cucumber taxonomy and systematics has in the past heavily relied on gross external and internal anatomy, ossicle assemblage in different tissues, and molecular characterisation, with coloration, habitat, and geographical and bathymethric distribution also considered important parameters. In the present paper, we made these observations and techniques in detail and complemented them with the novel technique of micro-computed tomography of the calcareous ring. We investigated a single European species, the so-called gravel sea cucumber,Neopentadactyla mixta(Östergren, 1898), using recently collected material from the Chausey Islands, Normandy, France. We redescribed the species, illustrated its ossicle assemblage through scanning electron microscopy, and visualised the calcareous ring through stacking photography and through micro-CT scanning. Additionally, a DNA fragment of 955 base pairs of the 18S ribosomal RNA gene was sequenced from one specimen, which showed a high similarity with the only sequence ofN. mixtapublicly available. We completed this integrative study by providing a detailed distribution of the occurrence ofN. mixtabased on published, verifiable accounts.