Geomonhystera michoacana, Prado-Vera & Ferris & Subbotin, 2018

Prado-Vera, Ignacio Cid Del, Ferris, Howard & Subbotin, Sergei A., 2018, Six new and one known species of Geomonhystera (Nematoda, Monhysteridae) from moss, an epiphytic plant and soil in México and Ecuador, Zootaxa 4471 (1), pp. 76-110 : 82-85

Geomonhystera michoacana sp. n.

( Fig. 3 A–G )

Measurements. Tables 2 and 3.

Female (n=5). Body strongly curved ventrally after fixation; cuticle 1 µm thick, with very fine striations; body setae rare, occasionally on tail and cervical region; head convex continuous with body contour, head width 13–14 (13.8±0.5) µm; lips triangular, fused at the base and clearly separated distally; inner labial papillae very small, coniform, 2.0 µm long; outer labial setae not segmented, 7–8 (7.5±0.6) µm long or 36–57 (48±9.0) % of head width; cephalic setae thin, 5–6 µm long or 36–43 (38±4.2) % of head width; amphid apertures rounded, 4.0–5.0 (4.2±0.5) µm diameter, 15–21 (17±2.4) µm from the anterior margin to the head, both amphids at the same level; pharynx muscular, 123–178 (147±21.8) µm long or 18–21 (19±1.3) % of the body length, and 368–537 (441±68.1) µm from vulva and 395–673 (495±108.6) µm from anus; nerve ring 63–80 (69±7.8) µm from the anterior end; cardia 6–10 (8.0±2.0) µm long and 7–12 (9.4±2.3) µm wide, composed of three small cells. Rectum 23–32 (27±4.0) µm long and 1.3–1.7 (1.5±0.2) times anal body diameter, thick, anterior end almost at level of vulva. Anterior anus lip slightly protruding. Gonad difficult to see in all specimens. Vulva lips slightly protruding; vagina short, post-vulval uterine sac absent; vulva-anus distance 24–37 (29±4.9) µm or 1.4–1.9 (1.6±0.2) times anal body diameter. Tail tapering evenly, 110–135 (118±10.4) µm long or 15–17 (16±1.1) % of the body length, with a few setae; three caudal glands ducted into an ampulla 5–10 (7.5±2.4) µm long and then into the conspicuous spinneret, 2–3 µm long.

Male. Unknown.

Diagnosis and relationships. Geomonhystera michoacana sp. n. has a body that is strongly ventrally curved after fixation; the cuticle appears smooth but actually is finely striated; relatively few setae, primarily located in cervical and tail regions; the tail is 15–17 (16±1.1) % of body length and the rectum is 23–32 (27±4.0) µm long.

Geomonhystera michoacana sp. n. is close to G. pervaga ( Argo and Heyns, 1973) Andrássy, 1981 , in the short body, in the fine striation of the cuticle; in the index b, in the distance from the anterior border of the amphid fovea to the head, in the position of the vulva and in the vulva-anus distance, and in having unsegmented outer labial setae. It differs in having a slightly longer tail. 110–135 (118±10.4) µm vs. 101 µm, a somewhat smaller range of index c, 5.7–6.8 (6.4) vs.6.4–7.4 (7.1), a larger amphid to head/head width, 1.1–1.6 (1.3) vs. <1.0 and in having fewer setae on the body. The new species is close to G. auvillis Saha, Lal & Singh, 2002 and G. aenariensis ( Meyl, 1953) Andrássy, 1981 , in the length of the body. It differs from G. auvillis in the finely-striated vs. smooth cuticle, in the presence vs. absence of body setae and in the index c, 5.7–6.8 (6.4±0.4) vs. 8.1–8.8, the length of the pharynx, 123–178 (147) vs. 100–112 µm and position of the vulva, 78–79.5 (78.6) vs. 80.6–86.2. It differs from G. aenariensis in the somewhat smaller c value, 5.7–6.8 (6.4) vs. 6.6–8.7, the shorter outer labial setae, 7.0–8.0 (7.5) vs 9.5 µm, and in the position of the vulva, 78–79.5 (78.6) vs. 80.3–84%.

Type locality and habitat. The Tzararacua National Park , Uruapan, Michoacan State, México 19° 25′ 29.4″ N, 102° 04′ 21.6″ W, elevation 1620 m asl, collected from moss on rock on June 21, 2009.

Type specimens. Holotype female on slide 10386; five paratype females on slide 10387 deposited in CNHE. One paratype is deposited in each following institutions UCRNC on slide number 28540, WaNeCo on slide number WT3717 and CPNC on slide number A-098.

Etymology. The species name recognizes that the type locality is in Michoacan State.

Figures

FIGURE 3. Geomonhystera michoacana sp. n.; Female (A–G). A, B, C: Anterior end body; D: Pharyngeo-intestinal junction; E: Vulva-anus region; F: Spinneret; G: Posterior end body.