Belondiridae Thorne, 1939

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 : 15-16

Family Belondiridae Thorne, 1939

17. Belondiridae gen. sp.— {58} (0, 0, 8, 0; 1)

Population structure and abundance. One female of an unidentified genus.

18. * Dorylaimellus parvulus Thorne, 1939 — {59, 69} (0, 0, 8, 9; 3)

Population structure and abundance. At site 59—11 females, at site 69—three juvenile specimens and four female (3–4x10 3/m2).

Ecology and distribution. Soil species (edaphobiont) but episodically occurs in small shallow water bodies. Relatively widespread. Recorded in several countries of Europe, South Africa , North (USA) and South ( Venezuela) America and Asia ( India) ( Siddiqi 1968; Peralta & Peña-Santiago 2000; Peña-Santiago 2006; Andrássy 2009b; Ahmad & Naz 2012). Not recorded from Vietnam until the present study.

Remarks. The individuals of this species found in Vietnam initially were erroneously described as the new species Enchodelus minor Gagarin & Gusakov, 2014 ( Gagarin & Gusakov 2014a). However, we soon received a message from a colleague (Dr. R. Peña-Santiago, University of Jaén, Spain) suggesting the incorrect identification of the species and its possible attribution to the genus Dorylaimellus , in particular to the known species D. parvulus . Re-analysis of the mounts confirmed that Dr. Peña-Santiago is correct and thus E. minor should be considered as one of the synonyms of D. parvulus (Gagarin & Gusakov 2015a) . The present species belongs to the sub-genus Axodorylaimellus Jairajpuri & Ahmad 1980 , under the genus Dorylaimellus Cobb, 1913 . Subsequently, some researchers recognized Axodorylaimellus as a separate genus ( Siddiqi 1983; Andrássy 2009b), but recent arguments suggest that, the independent status of the genus Axodorylaimellus is unsupported ( Ahmad & Naz 2012). No males are known ( Andrássy 2009b; Ahmad & Naz 2012).

19. * Lindseyus Ferris & Ferris, 1973 sp.— {17} (0, 0, 8, 0; 1)

Population structure and abundance. One male.

Ecology and distribution. Possibly amphibiont. Three out of four known species of the genus have been found in various aquatic biotopes (bogs, rice fields, rivers, etc.) in Europe, Asia, Africa and North America (Peña- Santiago 2006). No representatives of this genus had been recorded in Vietnam prior to this study.

20. * Paraoxydirus Jaraipuri & Ahmad, 1979 sp.— {15} (0, 4, 0, 0; 1)

Population structure and abundance. One female.

Ecology and distribution. Most likely an amphibiont. Four out of seven modern species were noted in aquatic environments (rice fields in India and Philippines) ( Peña-Santiago 2006). The genus was not previously recorded in Vietnam.