Grimaldina brazzai Richard, 1892

10. Grimaldina brazzai Richard, 1892 View in CoL

Localities and specimens found: 60 − 1♀.

Distribution and ecology. Until recently, it was believed that G. brazzai is the only representative of the genus that has a circumtropical distribution ( Smirnov 1992; Kotov et al. 2013a). According to modern concepts, this species lives only in the tropical regions of the Old World (Africa, Asia, Australia), while in the New World (tropics and subtropics of South, Central and North America) the genus is represented by a close species G. freyi Neretina et Kotov, 2017 ( Neretina & Kotov 2017). Despite the relatively wide distribution, finds of G. brazzai populations in nature are relatively rare and, as a rule, limited to a few specimens. To date, the species had been noted in most countries of South and Southeast Asia ( Fernando 1974, 1980; Idris & Fernando 1981; Rajapaksa & Fernando 1982a; Idris 1983; Michael & Sharma 1988; Maiphae et al. 2008; Tanaka & Ohtaka 2010; Rane 2011; Chatterjee et al. 2013; Kotov et al. 2013b; Van Damme et al. 2013; Sinev & Yusoff 2015, 2018; Lopez et al. 2017; Sharma & Sharma 2017; Tiang-nga et al. 2020; Choedchim & Maiphae 2023). In Vietnam, G. brazzai has been recorded only in the southern regions so far, including the Mekong Delta ( Shirota 1966; Sinev & Korovchinsky 2013; Le & Phan 2019; present study).

Grimaldina brazzai is a bottom dweller, living among detritus on the surface of sediments (Kotov 2006). In large water bodies (lakes, reservoirs), it prefers plant-filled littoral areas but occurs in shallow open zones too. The species is also recorded in other permanent and temporary water bodies: floodplains, rice fields, ponds, channels, etc. ( Idris & Fernando 1981; Tanaka & Ohtaka 2010; Sinev & Korovchinsky 2013; Sinev & Yusoff 2015; Neretina & Kotov 2017; Le & Phan 2019; Tiang-nga et al. 2020; Choedchim & Maiphae 2023). In our material, a single female of G. brazzai was registered in a small temporary forest lake (see Appendix 1).

Remarks. The status of the Asian and Australian populations of G. brazzai still needs to be carefully re-checked. Perhaps, this is a group of close species ( Chatterjee et al. 2013; Sinev & Korovchinsky 2013; Van Damme et al. 2013; Sinev & Yusoff 2015; Neretina & Kotov 2017).