<i>Schizoperavietnamica</i> sp. nov. (Copepoda, Harpacticoida, Miraciidae), a new species from a mangrove zone in Vietnam, with description of a new species, and a key to the species from the Oriental region, Sulawesi, and East Asia.

Abstract

<h4>Background</h4>A new species of harpacticoid copepod of the genus <i>Schizopera, S. vietnamica</i> sp. nov., was found. This is the first record of the genus for the country.<h4>Methods</h4>Samples were collected in July 2023, using a plankton net with a mesh size of 50 µm. The body parts of the specimens were dissected and mounted on glass slides. Morphological examination was carried out at 1,000× magnification. Habitus and appendages were then drawn using a drawing tube attached to a compound microscope.<h4>Results</h4>The new species differed from all its congeners in the relative length and chaetotaxy of the caudal rami, length of the proximal endopodal segment of the female first swimming leg relative to the exopod, armature of the middle and the distal endopodal segments of the second to the fourth swimming leg, segmentation and chaetotaxy of the fifth swimming leg. The new species resembles most <i>S. neglecta</i> in the loss of the inner seta on the proximal endopodal segment of the second to the fourth swimming legs, as well as in the shape and setular ornamentation of the inner margin of the caudal rami. A key to the species of the genus known from the Oriental region, Sulawesi and East Asia is provided.