Disparalona (Disparalona) ikarus Kotov et Sinev 2011

50. * Disparalona (Disparalona) ikarus Kotov et Sinev, 2011 Localities and specimens found: 25 – 45♀, 10♀ ov, 5♀ em, 65j; 26 – 108♀, 30♀ ov, 1♀ em, 169j. Distribution and ecology. This species of Disparalona was recently described from the Amur River basin in Russia (Kotov & Sinev 2011). To date, it has also been recorded in South Korea, China (including Hainan Island) and northeastern Thailand (Kotov et al. 2012; Sinev et al. 2015, 2020; Neretina et al. 2018; Korovchinsky et al. 2021b; Dadykin et al. 2023). This is the first mention of the species in Vietnam and it is currently the southernmost known point of the species distribution. Based on the data obtained until now, D. ikarus is obviously a benthic littoral crustacean, encountered both in open and vegetated areas. The species was mainly registered in rivers, reservoirs and lakes and less often in ponds, streams and ditches (Kotov & Sinev 2011; Kotov et al. 2012; Jeong et al. 2015; Sinev et al. 2015; Korovchinsky et al. 2021b). In our material, D. ikarus was found only once, but in large numbers, in the open and covered with water hyacinth sandy littoral of a small reservoir (see Appendix 1) Remarks. Prior to its description, D. ikarus has been identified mistakenly as D. rostrata (Koch, 1841) in some cases (Ji et al. 2015; Dadykin et al. 2023). It is possible that a number of previous indications of D. rostrata in Vietnam (Dang et al. 1980, 2002; Dang & Ho 2001) also actually refer to D. ikarus. Disparalona rostrata s. str. is now recognized as Palaerctic only (Neretina et al. 2018).