Chronogastridae Gagarin, 1975

Gusakov, Vladimir A. & Gagarin, Vladimir G., 2017, An annotated checklist of the main representatives of meiobenthos from inland water bodies of Central and Southern Vietnam. I. Roundworms (Nematoda), Zootaxa 4300 (1), pp. 1-43 : 33-34

Family Chronogastridae Gagarin, 1975

117. Chronogaster pseudotypica Gagarin & Nguyen, 2004 — {25, 32} (0, 4, 8, 0; 3)

Population structure and abundance. 1 to 4 females and females with eggs (up to 1x10 3/m2).

Ecology and distribution. Amphibiont. Described from the rivers of northern Vietnam ( Gagarin & Nguyen 2003). Later found in other regions of the country as well, including the wet soil habitats around plant roots and along the shoreline of water bodies ( Nguyen 2007). Not yet found outside Vietnam.

Remarks. Males are unknown ( Gagarin & Nguyen 2003; Nguyen 2007).

118. Chronogaster Cobb, 1913 spp.— {27, 33, 36, 51} (0, 7, 15, 0; 6)

Population structure and abundance. Single juvenile specimen or female of unidentified species in each sample.

Ecology and distribution. The majority of nematodes of the genus Chronogaster prefer aquatic environments but some species occur in terrestrial biotopes as well ( Andrássy 2005; Holovachov & De Ley 2006b).

Remarks. In Vietnam, beside C. pseudotypica , two more species of this genus have been reported: C. andrassyi Loof & Jairajpuri, 1965 and C. zujarensis Ocaña & Coomans, 1991 ( Gagarin & Nguyen 2005a; Nguyen & Nguyen 2005; Nguyen 2007). We failed to observe some distinguishing characteristics in the females found in the samples listed above.

119. * Rugoster cf. neomagnifica Siddiqi, Handoo & Siddiqi 2013 — {57} (0, 0, 8, 0; 1) Population structure and abundance. One female.

Ecology and distribution. Most likely an edaphobiont. Recently described from forest soil in Cote d’Ivoire ( West Africa ) ( Siddiqi et al. 2013). In Vietnam, found in a small forest pool into which it may have been accidentally introduced from a terrestrial habitat.

Remarks. In general, the structure of the Vietnamese female agrees with the original description but we failed to observe all features of morphology on the mount. Males unknown in the species of this genus ( Siddiqi et al. 2013).