Leberis punctatus (Daday, 1898)

30. * Leberis punctatus (Daday, 1898)

Localities and specimens found: 30 – 1♀; 46 – 1♀; 50 – 17♀, 1♀ ov, 3♀ em, 5j; 51 – 1♀.

Distribution and ecology. Leberis punctatus (formerly Alona punctata Daday, 1898 ) is a comparatively rare member of the genus recently redescribed in detail ( Neretina & Sinev 2016). The species is generally distributed in the Afrotropical and Oriental biogeographic realms but is also recorded in southern Spain ( Korovchinsky et al. 2021b). In the Oriental area, Leberis punctatus has so far been known only in Sri Lanka, India and Thailand ( Padhye & Dumont 2015; Neretina & Sinev 2016; Sinev 2016; Sharma & Sharma 2017; Korovchinsky et al. 2021b). The present study is the first direct reference of this species in Vietnam. The record of L. diaphanus (King, 1853) in our previous report on the meiofauna of Vietnam ( Gusakov et al. 2014) should also be attributed to L. punctatus (as we established after re-examination of the material). In turn, L. diaphanus is also known in Vietnam ( Sinev & Korovchinsky 2013; Phan et al. 2015; Sinev & Semenyuk 2021).

The lifestyle and ecology of L. punctatus are weakly studied. Most likely, this chydorid is a typical littoral inhabitant associated with vegetation (Sinev 2016; Korovchinsky et al. 2021b). The species occurs in different types of water bodies ( Neretina & Sinev 2016). We found it in two natural vegetation-rich lakes, on the bottom and in the roots of floating plants. Among the roots of water hyacinth, this crustacean was the most numerous (see Appendix 1).

Remarks. In South and Southeast Asia, L. punctatus is occurring together with another very similar, more common relative: L. diaphanus ( Neretina & Sinev 2016; Sinev 2016). It cannot be ruled out that some previous indications of L. diaphanus in the region actually refer to L. punctatus , which confirms our example of an initially erroneous report that the former species was found in Vietnamese material instead of the latter (see note above). Thus, L. punctatus is likely to be more widespread in the Oriental region than currently believed.