A new species of genus Tropodiaptomus Kiefer, 1932 (Crustacea: Copepoda: Calanoida: Diaptomidae) from Thailand

ABSTRACT

Tropodiaptomus megahyaline sp. nov. is described and illustrated based on materials collected from a rice field near Songkhram River Basin, Bueng Kan Province, Northeastern Thailand. This new species can be distinguished from its congeners by features of the male such as (1) antepenultimate segment of the right antennule with straight spinous process reaching middle of next segment; (2) basis of the right P5 with three process; (3) basis of both right and left P5 with longitudinal hyaline lamella, length about 1/3 as long as basis on the inner margin; (4) second segment of exopod of the right P5 trapezoidal, with two semicircular hyaline knobs, and one triangular process on distal outer margin of dorsal surface; and (5) inner margin of the exopod of the left P5 with the proximal part larger than the distal part. Differences among Asian Tropodiaptomus species are noted, and an identification key for both females and males of this genus is proposed.

KEYWORDS:

• Asian species
• hyaline lamella
• Songkhram River Basin
• Tropodiaptomus megahyaline

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This research is supported in part by the Graduate Program Scholarship from The Graduate School, Kasetsart University;  the Centre of Excellence on Biodiversity (BDC) Office of Higher Education Commission (BDC-PG2-161004); graduate study development scholarship from the National Research Council of Thailand as of 2020 fiscal year and Department of Zoology, Faculty of Science, Kasetsart University.