Brevitobrilus larae, Tsalolikhin, 2020

Tsalolikhin, S. Ya., 2020, Two new species of free-living nematodes (Nematoda) from Vietnam, Zoosystematica Rossica (Zoosyst. Rossica) 29 (1), pp. 11-16 : 12-15

Brevitobrilus larae sp. nov.

( Figs 5– 9 )

Holotype. Female, Vietnam, Kon Tum Prov., Kon Plong Distr., Kon Chu Rang Nature Reserve , pond in forest, 1077 m a.s.l., 14°35′22″N, 108°25′04″E, 10 Oct. 2018, coll. L. Iogansen. Microscope slide No. A-9195 , ZISP.

Paratypes. 6 females, same data as for holotype .

Description. Females. Morphometric descriptions of the holotype and paratypes are given in Table 2 . Cuticle thin, in total about 2 µm thick in middle of body. Outline of head round and not offset. Head with six distinct lips, each with one small papilla. Longer cephalic setae 6–8 µm, shorter setae about 4 µm. Width of head 19 µm. Buccal cavity 8–10 (9) µm wide and 10 µm long; total depth of stoma (buccal cavity and pockets) 20–26 (23) µm; two pockets separated by short isthmus, each pocket with one teeth, distance between tops of teeth 9 µm. Amphid openings at level of bottom of buccal cavity or at level of first pocket; amphid diameter 4 µm, approximately one-sixth part of corresponding body width. Reproductive system didelphic, amphidelphic; ovaries reflexed, oocytes arranged in double rows in germinal zone; only two females with mature eggs in uterus. Depth of vagina corresponding to one-third – half of body width. Tail elongate-conoid, spinneret 1–2 µm long; subterminal setae absent.

Male not found.

Comparision. The new species Brevitobrilus larae sp. nov. most closely resembles B. orientalis Tsalolikhin, 2013 , which was described from Kazakhstan ( Tsalolikhin, 2013). The new species differs from B. orientalis by longer body (851−1048 µm vs 788−871 µm), longer (6−8 µm vs 5−6 µm) and thinner, not hornlike cephalic setae, in longer tail (111−147 µm vs 77−82 µm) and absence of subterminal setae.

Etimology. The species is named after the herpetologist Larissa (Lara) Iogansen, who collected material for me in the jungles of Vietnam.

Figures

Figs 1–9. Morphology of Monhistera vietnamica sp. nov. (1–5) and Brevitobrilus larae sp. nov. (6–9). 1, 6, entire body of female; 2, 7, head; 3, esophagus; 4, 8, vulval section; 5, 9, tail. Scale bars: 2, 7 – 5 µm; 3, 4, 5, 8, 9 – 20 µm; 1, 6 – 50 µm.