4. Ilyocryptus isanensis Kotov, Stifter et Sanoamuang, 2005

Localities and specimens found: 101 − 1♀.

Distribution and ecology. This is a rare species discovered in Thailand (Kotov et al. 2005; Kotov & Štifter 2006), probably endemic to Southeast Asia. At present, it is known only from Thailand and Vietnam (Kotov & Štifter 2006; Maiphae et al. 2008; Jeong et al. 2012; Korovchinsky 2013; Choedchim & Maiphae 2023; Kotov et al. 2024).

The lifestyle and ecology of this species are unstudied. Like other ilyocryptids (Kotov 2006; Kotov & Štifter 2006), it is obviously a typical bottom dweller. In Thailand, I. isanensis was recorded in a temporary pond and a rice field (Kotov et al. 2005; Choedchim & Maiphae 2023). The only female from our material was found in the Mekong Delta, in the channel zone of the Co Chien Branch (see Appendix 1).