A new species of the genus Smacigastes Ivanenko & Defaye, 2004 (Tegastidae, Harpacticoida, Copepoda) from the Onnuri Vent Field in the Indian Ocean

By

Kim, Jong Guk
Lee, Jimin

Type

Article

Date of Publication

2020

Original Publication

Zoosystematics and evolution

Volume

96

Pages

699--714

Subjects

deep sea , Dichotomous key , Hydrothermal vent , meiofauna , northern Central Indian Ridge

Contributed by

Pensoft Publishers

Language

English

Published by

Sofia Pensoft

Identifiers

DOI: https://doi.org/10.3897/zse.96.54507

 

Abstract

The genus Smacigastes Ivanenko & Defaye, 2004 (Harpacticoida, Copepoda) is the most primitive genus in the family Tegastidae Sars, 1904, occurring in deep-sea chemosynthetic environments, such as hydrothermal vents, cold seeps, whale falls and wood falls. Our exploration of the Onnuri Vent Field, the sixth active hydrothermal vent system in the Central Indian Ridge, resulted in the discovery of a new species in the genus Smacigastes. A detailed morphological analysis of S. pumila sp. nov. reveals that it most resembles S. barti Gollner, Ivanenko & Martínez Arbizu, 2008, described from a hydrothermal vent in the East Pacific Ridge; the new species can be distinguished from the existing species by the 8-segmented female antennule, the absence of an abexopodal seta on the antennary basis, the mandibular exopod represented by a single seta and the exopod of the first leg with five setae. This is the first record of Smacigastes in the Indian Ocean. A dichotomous key to species of the genus Smacigastes worldwide is provided.