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.
Highlights
The calanoid copepod genus Tortanus Giesbrecht, 1898 (Calanoida, Tortanidae) currently comprises 47 species (Walter and Boxshall, 2018; http://www.marinespecies. org); these are mainly distributed in coastal waters of the Indo-West Pacific and the northwestern Atlantic (Mulyadi et al, 2017)
The present study describes a new species of Tortanus (Atortus) from a coral lagoon of Minicoy Island, southeastern Arabian Sea; molecular data of the new species are provided to determine the female–male correspondence
Tortanus (Atortus) specimens were sorted from the original samples, and mouthparts and swimming legs were dissected with needles in a 50:50 solution of glycerin and distilled water
Summary
The calanoid copepod genus Tortanus Giesbrecht, 1898 (Calanoida, Tortanidae) currently comprises 47 species (Walter and Boxshall, 2018; http://www.marinespecies. org); these are mainly distributed in coastal waters of the Indo-West Pacific and the northwestern Atlantic (Mulyadi et al, 2017). Org); these are mainly distributed in coastal waters of the Indo-West Pacific and the northwestern Atlantic (Mulyadi et al, 2017). The subgenus Atortus, accommodating 32 nominal species (Mulyadi et al, 2017), is regarded as the most advanced and is distributed exclusively in the Indo-West Pacific region. It tends to occur in more or less oligotrophic, clear, high-salinity (34–40 PSU) waters sometimes strongly influenced by warm currents, or in coral reefs and seagrass beds (Ohtsuka and Kimoto, 1989; Ohtsuka and Reid, 1998; Ohtsuka et al, 2000; Nishida and Cho, 2005; Nishida et al, 2015; Mulyadi et al, 2017). It must be mentioned that cooccurrence of multiple closely related species of Tortanus
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
