Tripylina iandrassyi, Prado-Vera, Ignacio Cid Del, Ferris, Howard & Nadler, Steven A., 2016

Prado-Vera, Ignacio Cid Del, Ferris, Howard & Nadler, Steven A., 2016, Five new species of the family Trischistomatidae (Nematoda: Enoplida) from North and Central America, with keys to the species of Trischistoma and Tripylina, Zootaxa 4109 (2), pp. 173-197 : 187-190

Tripylina iandrassyi n. sp.

Measurements. Tables 2 , 3 .

Tripylina iandrassyi was collected by the first author from soil and litter layers at an ecological reserve in La Mancha, Veracruz, México in August 2012 and again in August, 2013.

Body long and slender in both females and males with the posterior end spiraling ventrally after fixation. Cuticle thin, 1 µm thick, with striations, a few anastomoses visible in SEM preparations but indiscernible under LM. Labial region asymmetric with three conspicuous, laterally expanded, triangular-shaped lips 15–21 (18±0.62) µm width, continuous with slender neck. Two small conical inner labial papillae, 2 µm long, in the base of each lip; outer labial setae strongly developed, 10–12 µm (11±0.2) long, or 50–63 (58±1.3)% of the head width; cephalic setae 3–5 µm (4.0±0.4) long, separated from the outer labial setae by 1 µm. Amphids oval shaped, 10–20 (16±0.8) µm from the anterior end. Mouth opening shifted dorsally; dorsal wall of mouth cavity thickened; dorsal tooth directed posteriad, large (2 µm long), lying 15–20 (17±0.4) µm from the anterior end; subventral teeth minute, 1–2 µm posterior to dorsal tooth (Figs. 9,10).

Pharynx heavily muscular in the posterior region, 164–226 (194±4.5) µm long. Distance from posterior end of pharynx to vulva 559–1005 (762±33.9) µm. Pharyngeal-intestinal junction with large cardiac glands and two pericardiac cells, 7–12 (8.9±0.4) µm long and 15–20 (17.6±0.5) wide. Two pairs of ventromedian setae in the cervical region in both females and males, the anterior pair 49–77 (60±5.0) µm and 62–79 (71±8.5) µm and the posterior pair 125–150 (134±8.0) µm and 95–163 (129±34) µm from the anterior end. A few somatic setae present along the body. Rectum 9–19 (14±0.9) µm long and 0.43–1.1 (0.76±0.06) times as long as anal body diameter ( Fig. 9 ).

Female (n=15). Monovarial, prodelphic, ovary reflexed and short, uterus in some specimens with some spermatozoa; gonad 198–330 (245±11.6) µm long and 15.6–26% of body length. Vulval lips not protruding, vagina short, 5–6 (5.8±0.2) µm long and with two conspicuous oval sclerotized plates. Post-uterine sac 65–198 (110±11.0) µm long with a few ovoid sperm, 8–13 (10±0.68) µm long and 4.6–9.0 (6.3±0.5) µm wide, one pole with a small protuberance. Vulva to anus distance 118–292 (188±12.5) µm. Tail curved ventrally, 29.5–46.3 (34.3±1.4) µm long, 2.2–4.1 (3.0±0.15)% of the body length, with the same width as anal body diameter, 16–22 (19±0.6), for the first one third and then tapering to a cylindrical shape through the posterior two thirds. One pair of small laterodorsal papillae posterior to the anus. Caudal glands occupy almost the full width of the tail. Spinneret 2 µm long.

Male (n=4). Average body length similar to that of female (1.1–1.4 mm). The buccal lips strongly developed as in females, 16–22 (19±1.3) µm wide; two cervical setae were observed in two specimens, the anterior 62–79 µm and the posterior 95–163 µm from the anterior end. Genital tract 546–872 (709±92.5) µm long, occupying 46–73% of the body length. Spermatozoa ovoid in shape. Five precloacal supplements present, the first 4.2–8.4, second 16.8–25.3, third 37.9–54.7, fourth 63.2–92.6, and the fifth 80–117.9 µm from the cloaca.

Spicules sickle-shaped, 37.9–47.0 (42.5±2.4) µm long, with bifid terminus, not completely surrounded by muscle layer; gubernaculum distinct, an inverted U shape, 6–12 (8.3±1.4) µm long. Tail 35.8–50.5 (42±3.7) µm long, 3.0–3.9% of entire length of body; tapering to a cylindrical shape in the posterior two thirds. A pair of conspicuous glandular orifices present at the outer edges of the posterior cloaca lip, in one specimen there was a secretion from the left orifice. One pair of small latero-dorsal papillae posterior to the anus. Caudal glands and spinneret similar to those of the female Figs. 9,11).

Type locality and habitat. Surface soil collected from around a banana tree at the La Mancha Ecological Institute, Municipio de Actopan, Veracruz State, México, N 19°35'25.4" W 96°22'50.2", 5 m above sea level.

Etymology. This new species is named in honor of the eminent professor and systematist of the Phylum Nematoda, the late Dr. István Andrássy.

Type specimens. Holotype female CNHE 9252 and paratypes CNHE 9253 of Tp. iandrassyi are deposited in CNHE; paratypes in CNCP (A-083-2), UCRNC and USDANC.

Diagnosis and relationships. Tripylina iandrassyi n. sp. is characterized by the strong development of the buccal lips and the asymmetric head region, the dorsal tooth directed posteriad, the subventral teeth posterior to the dorsal tooth, the thickness of the dorsal stoma wall, two cervical setae in both females and males, and the presence of a post-uterine sac. Males have five papillate ventromedian supplements confined to the precloacal region. Spicules not clearly surrounded by a muscular sheath and glandular orifices in the lateral area of the posterior cloaca lip (Figs. 9,10,11).

Besides Tp. iandrassyi n. sp., the only two other species of the genus Tripylina Brzeski, 1963 reported with a post-uterine sac, a thick dorsal wall of the stoma and males with sickle-shaped spicules are Tp. longa Brzeski & Winiszewska-Ślipińska, 1993 , and Tp. bravoae Cid del Prado-Vera, Ferris, Nadler & Lamothe-Argumedo, 2012 (Zhao 2009, Cid del Prado-Vera et al. 2012). Trischistoma iandrassyi n. sp. and Tp. bravoae have distinct nucleotide sequences when compared to each other and to all Tripylina species sequences from GenBank (Cid del Prado-Vera et al. 2 012).

Tripylina iandrassyi n. sp. is similar to Tp. longa in the posteriad orientation of the dorsal tooth, the thickness of the dorsal stoma wall, in the conspicuous sclerotised pieces of the vagina and in the position of vulva. Nevertheless, it can separated from that species in the length of the body 0.9–1.4 vs. 1.5–1.7 mm, the length of the outer labial setae 10–12 (11±0.2) vs. 15–18 µm, in the length of the pharynx 164–226 (194±4.5) vs. 216–242 (225) µm, the length of the tail 29–46 (34.3±1.4) vs. 49–63 (56) µm, in the posterior position of the minute subventral teeth and in strong development of buccal lips. Also Tp. iandrassyi n. sp. is similar to Tp. bravoae in the length of the body, the position of the vulva, the absence of body pores and excretory pore, but it differs, in females, in the length of the pharynx 164–226 (194±4.5) vs. 236–320 (280±8.0) µm, the length of the tail, 30–46 (34±1.4) vs. 44–56 (53±1.6) µm, the vulva to anus distance 117–292 (188±12.5) vs. 141–325 (264) µm, and in the strong development of the buccal lips. The males differ in the length of the body, 1.1–1.4 (1.25±0.07) vs. 1.5–2.0 (1.7±0.9) mm, length of the pharynx, 198–226 (212±8.2) vs. 236–302 (247±5.0) µm, in the tail length, 36–51 (42.1±3.7) vs. 46–72 (58±2.8) µm, and in the length of the outer labial setae, 11–15 (12.3±0.95) vs. 13–20 (17±1.0) µm (Tables 2,3).

Molecular characteristics. Tripylina iandrassyi was distinct in nucleotide sequence when compared to 15 other congeneric taxa, with 9 or more sequence differences in pairwise comparisons.

Figures

FIGURE 9. Tripylina iandrassyi n. sp. Female. A – E, H. A. Pharynx; B. Posterior end; C: Anterior end; D: Pharyngeo-intestinal junction; E: Vulva region; H: Spermatozoa; Male. F: Anterior end; G, I: Posterior region lateral.

Tables

TABLE 3. Males of Tripylina spp. in which females have a post-uterine sac (Tripylina iandrassyi n. sp., Tp. bravoae and Tp. longa). All measurements are in µm, except for L (mm); mean ± standard deviation, and ranges.

Character Tp. iandrassyi Paratypes n=4	Tp. bravoae Paratypes n= 10	Tp. longa Paratypes n=1
L 1.25 ±0.07 1.1–1.4 mm	1.7±0.9 1.5–2.0 mm	1.7 mm
a 41±3.1 35–50	49±1.6 42–58	41
b 5.9±0.2 5.3–6.4	5.4±0.2 5.3–7.3	7.1
c 30.5±2.1 25.8–36	31±1.8 23–39	28.3
c’ 1.7±0.16 1.4–2.0	1.9±0.1 1.5–2.8	2.0
T% 57±6.2 46–73	50 42–59
Max. body diam. 30±1.0 29–33	36±1.0 30–40
Anal body biam. 25	30±1.1 25–37
Dorsal tooth to anterior 18.8±0.75 17–20	24±1.1 20–27
Nerve ring 89.0	100±6.3 94–113
Pharynx length 212±8.2 198–226	247±5.0 236–302	247
Pharynx (% of body length) 17±0.68 16–19	16±0.6 14–19
Tail length 42±3.7 36–51	58±2.8 46–72
Tail (% of body length) 3.4±0.2 3–3.9	5.2±0.3 2.5–4.2
Spinneret 1.5±0.5 1.0–2.0