Saturday, October 28, 2023

[Crustacea • 2023] Oxyarcturus holoacanthus • Revision of the Genus Oxyarcturus (Isopoda: Valvifera: Antarcturidae), with A Description of A New Deep-sea Species from Argentina


Oxyarcturus holoacanthus 
Pereira, Roccatagliata & Doti, 2023

 
Abstract
A new antarcturid isopod, Oxyarcturus holoacanthus sp. nov., is fully described based on seven specimens collected in the Mar del Plata submarine canyon at 2950 m depth, during the “Talud Continental III” expedition on board the Argentinian RV “Puerto Deseado”. Oxyarcturus holoacanthus sp. nov. is closely related to O. spinosus (Beddard, 1886), from which it can be distinguished by the body spine pattern. The penial plate, a novel character for the genus Oxyarcturus, as well as for the family Antarcturidae, is described in detail. The species O. dubius (Kussakin, 1967) and O. beliaevi (Kussakin, 1967) are considered as incertae sedis until further morphological and molecular data can clarify their taxonomic position. An update of the geographic and bathymetric records of the genus Oxyarcturus is provided.

Key Words: Mar del Plata submarine canyon, Oxyarcturus beliaevi (Kussakin 1967), Oxyarcturus dubius (Kussakin 1967), Oxyarcturus holoacanthus sp. nov., Southwest Atlantic

Oxyarcturus holoacanthus sp. nov. Photographs.
Holotype male (MACN-In 44318). A. Habitus, lateral view. Paratype male (MACN-In 44319-a); B. Pleon, dorsal view.
Paratype female (MACN-In 44319-b); C. Head and pereonites 1–4, dorsal view;
D. Habitus, lateral view. cl – caudolateral spine; m – medial spine; l – lateral spine.

Oxyarcturus holoacanthus sp. nov.

Etymology: The specific epithet combines two Greek words holos = “entire, complete” and akantha = “spine”, referring to the many long and acute spines that cover the body surface of this species.


Emanuel Pereira, Daniel Roccatagliata and Brenda L. Doti. 2023. Revision of the Genus Oxyarcturus (Isopoda, Valvifera, Antarcturidae), with A Description of A New Deep-sea Species from Argentina. Zoosystematics and Evolution. 99(2): 457-472. DOI: 10.3897/zse.99.106667