A new species of Tortanus (Atortus) (Copepoda, Calanoida, Tortanidae) from Minicoy Island, southeastern Arabian Sea

Abstract

A new species of the planktonic calanoid copepod genus Tortanus, subgenus Atortus, is described from a coral reef lagoon of Minicoy Island, southeastern Arabian Sea. The new species is included in the tropicus group, which is mainly distributed in the tropical and subtropical waters of Southeast Asia. The species can be distinguished from all other species of the tropicus group by the asymmetrical fifth pedigerous somite with notched left margin and triangular lobe in the right, hyaline coupling device with larger left process, 2 ventrolateral spines in the genital compound somite, and caudal rami with 2 medial rounded processes in the female. In the male, serrated ridge of the right antennule slightly raised from the surface plane, beak-shaped medial process on the right fifth leg coxa, triangular medial process on the basis, and strongly curved subdistal seta on the left fifth leg. Mitochondrial cytochrome oxidase subunit I sequences of the specimens obtained with 642 base pairs confirmed the female-male correspondence and revealed the genetic identity of the species, which is herein compared with mtCOI sequences of congeners.

From Phenotypes to Genotypes and Back: Toward an Integrated Evaluation of Biodiversity in Calanoid Copepods

“…Our dataset includes females of studied calanoid species due to their high abundance and sex ratio in our samples. However, recent studies (Francis and Nishida, 2018;Francis and Bijoy Nandan, 2019) suggest that morphological and genetic data should be generated and established both for female and male specimens. The mitochondrial gene COI, considered the gold standard for metazoan identification (Hebert et al, 2003a,b), proved itself to be a good marker for species delimitation (Bucklin et al, 2010c(Bucklin et al, , 2011(Bucklin et al, , 2021Blanco-Bercial et al, 2014;Cornils and Held, 2014).…”