Magnaspina siamensis

34. Magnaspina siamensis (Sinev et Sanoamuang, 2007) Localities and specimens found: 25 – 2♀ em; 26 – 1♀, 1♀ ov. Distribution and ecology. Magnaspina siamensis (formerly Alona siamensis Sinev et Sanoamuang, 2007) is a rare species described from Thailand, an endemic to the Oriental region (Sinev & Sanoamuang 2007; Sinev 2016). Currently, the species is also known from Malaysia, Laos, India and South Vietnam (Korovchinsky 2013; Kotov et al. 2013b; Sinev & Korovchinsky 2013; Sinev 2016; Sousa & Padhye 2020). In Vietnam, Magnaspina siamensis was first recorded as Alonella dentifera Sars, 1901 by Shirota (1966) (see Remarks below for details). The lifestyle and ecology of Magnaspina siamensis are little studied. To date, this chydorid has been discovered mainly in small, vegetated water bodies, namely swamps, rice fields, ponds, ditches, floodplains (Sinev & Sanoamuang 2007; Sinev & Korovchinsky 2013; Sousa & Padhye 2020; Choedchim & Maiphae 2023). In our material, a few individuals of this species were found in the open and overgrown littoral of a small reservoir (see Appendix 1). Remarks. It should be noted that probably all records of Alonella dentifera -like populations (later known as Alona or Coronatella dentifera (Sars, 1901)) from the Oriental region (e.g., by Shirota (1966), Idris & Fernando (1981), Idris (1983), Maiphae et al. (2005, 2008), etc.) are in fact Magnaspina siamensis too (Sinev & Sanoamuang 2007; Van Damme et al. 2010; Chartejee et al. 2013; Kotov et al. 2013b; Van Damme & Sinev 2013; Sousa et al. 2016b; Choedchim & Maiphae 2023). The recent species M. dentifera (Sars, 1901), the “successor” of Alonella dentifera, originally described from Brazil, is now considered an inhabitant of the Neotropics only (Sousa et al. 2016b).