Tryonia zaragozae, Hershler, Robert, Liu, Hsiu-Ping & Landye, Jerry, 2011

Hershler, Robert, Liu, Hsiu-Ping & Landye, Jerry, 2011, New species and records of springsnails (Caenogastropoda: Cochliopidae: Tryonia) from the Chihuahuan Desert (Mexico and United States), an imperiled biodiversity hotspot, Zootaxa 3001, pp. 1-32 : 9

publication ID	https://doi.org/ 10.5281/zenodo.278442
DOI	https://doi.org/10.5281/zenodo.5629191
persistent identifier	https://treatment.plazi.org/id/03E687C5-BF7F-8306-FF2E-16ADFF581E4F
treatment provided by	Plazi
scientific name	Tryonia zaragozae
status	sp. nov.

Treatment

Tryonia zaragozae sp. nov.

( Figs 4 View FIGURE 4 E–G, J–L, P–R, 5B)

Tryonia n. sp. 2.— Hershler et al. 2005: 1757 (COI sequence).

Types. Holotype, USNM 873286, springs ca. 4.8 km north-east of Ignacio Zaragoza along the south side of Highway 5, Chihuahua, 29º39'47.9" N, 107º44'25.8" W, leg. J.J.L. et al., 25/viii/1971. Paratypes (from same lot), USNM 873260, USNM 873289, USNM 874120, USNM 1153679.

Etymology. The species name is a geographic epithet referring to the nearby town of Ignacio Zaragoza.

Referred material. CHIHUAHUA. USNM 854942, topotypes, leg. R.H. and J.J.L., 8/xii/1998.

Diagnosis. Shell medium-sized, conic or turriform, apex usually eroded; penis having two distal papillae on inner edge and a basal papilla both on the inner and outer edges. Contrasted with T. peregrina above.

Description. Shell ( Fig. 4 View FIGURE 4 E–G) up to 6.7 mm tall, whorls 6.5–8.75, spire height 150–200% width of shell, sexual dimorphism of shells not obvious. Teleoconch whorls weakly convex to almost flat, evenly rounded or, less frequently, narrowly shouldered, with adpressed sutures. Aperture sharply angled adapically, parietal lip usually incomplete, usually adnate when complete, rarely slightly disjunct, umbilicus absent. Outer lip thin, orthocline or weakly prosocline. Sculpture of strong growth lines and well developed spiral threads ( Fig. 4 View FIGURE 4 L). Periostracum tan.

Shell measurements (mean in parentheses): height 3.85–4.65 mm (4.20), width 1.60–1.78 mm (1.69), body whorl height 2.10–2.41 mm (2.21), body whorl width 1.53–1.67 mm (1.60), aperture height 1.23–1.41 mm (1.31), aperture width 0.91–1.08 mm (0.99), total number of whorls 6.50–7.25 (6.78) (USNM 1153679, n = 15).

Measurements of holotype: height 4.39 mm, width 1.68 mm, body whorl height 2.30 mm, body whorl width 1.60 mm, aperture height 1.35 mm, aperture width 1.01 mm, 7.25 whorls.

Edges of last operculum whorl strongly frilled on outer side ( Fig. 4 View FIGURE 4 J); muscle attachment scar margins somewhat thickened on inner side of operculum ( Fig. 4 View FIGURE 4 K). Radula ( Fig. 4 View FIGURE 4 P-R): dorsal edge of central radular teeth concave, basal tongue rounded or V-shaped, median cusps elongate, distally pointed, parallel-sided proximally, lateral cusps five–six, basal cusps two–three (innermost larger) ( Fig. 4 View FIGURE 4 Q). Lateral teeth having two–three cusps on inner and four–six cusps on outer side, length of outer wing 175–200% width of cutting edge, central cusp pointed ( Fig. 4 View FIGURE 4 R). Inner marginal teeth with 24–35 cusps, outer marginal teeth with 30–40 cusps. Radula data are from USNM 1153679.

Animal darkly pigmented. Penis ( Fig. 5 View FIGURE 5 B) having two distal papillae on inner edge and a basal papilla both on the inner and outer edges (30 of 30 specimens). Papilla on outer edge sometimes very small. Distal bulb of penis expanded laterally on inner side, lightly pigmented; stylet small. Penial duct undulating for most of length. Penial data are from USNM 1153679.

Distribution and habitat. Tryonia zaragozae is known only from its type locality, a large (ca. 0.01 km 2) cienega and spring system ( Fig. 6 View FIGURE 6 C) in the upper Río Casas Grandes drainage ( Fig. 1 View FIGURE 1 , locality 4). Snails were collected (on gravel and on soft substrates) from several springs and bogs (29–30°C) within this cienega. This habit has been severely degraded by overgrazing in recent years, although one of the larger head springs is now fenced (first noted in 1998).

References

Figures

FIGURE 6. Photographs of habitats of species treated in this paper. A. Ojo Vareleño, Chihuahua, type locality of T. peregrina sp. nov. (photograph taken on 16 / ix / 1990). B. Main spring in Yepomera, Chihuahua, T. peregrina habitat (18 / ix / 1990). C. Springs northeast of Ignacio Zaragoza, Chihuaua, type locality of T. zaragozae sp. nov. (8 / xii / 1998). D. Western-most head spring, Ojos de Arrey, Chihuahua, type locality of T. angosturae sp. nov. and T. ovata sp. nov. (7 / xii / 1998). E. Spring in northern part of El Molino, Chihuahua, type locality of T. molinae sp. nov. (26 / iv / 2010). F. Ojo del Apache, Chihuahua, type locality of T. contrerasi sp. nov. (14 / xii / 1998). G. Ojo Carbonero, Chihuahua, T. contrerasi habitat (2 / iv / 1991). H. Outflow of Ojo Caliente, Chihuahua, type locality of T. taylori sp. nov. (7 / xii / 1998). I – J. El Ojo de Servin, Chihuahua, T. taylori habitat (27 - viii- 1971, 7 / xii / 1998, respectively). K. Seeps in La Cienega, Texas, type locality of T. metcalfi sp. nov. (6 / xii / 2001). L – M. Balneario de San Diego de Alcala, Chihuahua, type locality of T. chuviscarae sp. nov. and T. minckleyi sp. nov. (4 / xii / 2001). N. Springs southeast of Julimes, Chihuahua, type locality of T. julimesensis sp. nov. (5 / iv / 1991). O. El Ojito (outflow), southwest of Talamantes, Chihuahua, type locality of T. allendae sp. nov. (10 / xii / 1998). P. Caroline Spring, Oasis Ranch, Texas, type locality of T. oasiensis sp. nov. (30 / iii / 2009). Q. Spring in Nombre de Dios, Durango, T. seemani habitat (2 / ix / 1971). R. Spring in Amado Nervo, Durango, T. seemani habitat (7 / iv / 1991).