14. Macrothrix spinosa King, 1853

Localities and specimens found: 25 – 4♀, 1♀ ov, 13j; 26 – 1♀, 2j; 32 – 2♀, 1♀ em, 1j; 51 – 2♀, 1j.

Distribution and ecology. Macrothrix spinosa is one of the best-known representatives of the genus, especially in tropical and subtropical regions around the world (Smirnov 1992; Korovchinsky et al. 2021b). Kotov et al. (2013a) indicate it for all biogeographic zones except Antarctica. This macrothricid is very common in the Oriental and adjacent states (Chiang & Du 1979; Idris 1983; Michael & Sharma 1988; Sanoamuang 1998; Rane 2002, 2005, 2011; Maiphae et al. 2005, 2008; Tanaka & Ohtaka 2010; Chatterjee et al. 2013; Korovchinsky 2013; Kotov et al. 2013b; Van Damme et al. 2013; Ji et al. 2015; Sinev et al. 2015, 2020; Sinev & Yusoff 2015, 2018; Lopez et al. 2017; Sharma & Sharma 2017; Choedchim & Maiphae 2023), including Vietnam (Dang & Pham 1979; Dang et al. 1980, 2002; Dang & Ho 2001; Duong et al. 2008; Sinev & Korovchinsky 2013; Gusakov et al. 2014; Zhdanova 2014; Phan et al. 2015). Note that in a number of the afore-cited sources, M. spinosa is given under the synonymous name, Macrothrix goeldi Richard, 1897 (Smirnov 1992; Kotov et al. 2013a).

Macrothrix spinosa is a littoral species primarily associated with plant-filled areas. It occurs in almost all types of water bodies, both in plankton and benthos (Idris 1983; Phan et al. 2015; Sinev et al. 2015, 2020; Choedchim & Maiphae 2023). In our material, this crustacean was found in a reservoir and a natural lake, including a sample from the roots of floating moss (see Appendix 1).

Remarks. It is possible that populations of M. spinosa from different parts of the world represent a complex of similar species. This issue requires further detailed research (Korovchinsky et al. 2021b).