24. * Graptoleberis cf. testudinaria (Fischer, 1851)

Localities and specimens found: 50 – 1♀.

Distribution and ecology. Graptoleberis testudinaria s. lat. has an almost cosmopolitan distribution, but populations recorded around the world (and the Oriental area is not an exception) probably represent a complex of closely related, separate species (Chatterjee et al. 2013; Van Damme et al. 2013; Sinev 2016, 2017; Korovchinsky et al. 2021b). This crustacean, although rare, is quite widely known in the Oriental region (Fernando 1974, 1980; Chiang & Du 1979; Idris & Fernando 1981; Idris 1983; Sharma & Michael 1987; Michael & Sharma 1988; Sanoamuang 1998; Maiphae et al. 2008; Rane 2011; Chatterjee et al. 2013; Korovchinsky 2013; Ji et al. 2015; Sinev et al. 2015, 2020; Sinev 2016; Sharma & Sharma 2017; Tiang-nga et al. 2020; Choedchim & Maiphae 2023; Dadykin et al. 2023). In Vietnam, G. testudinaria has not been recorded before. This is its first finding in the country.

Graptoleberis testudinaria is a highly specialized phytophilic chydorid, adapted to crawling on submerged substrates. It lives in a wide variety of water bodies, mainly in thickets of aquatic plants (Fryer 1968; Smirnov 1971; Korovchinsky et al. 2021b). The only female in our material was encountered in the root system of a water hyacinth (see Appendix 1).