San Bernardino Springsnail

Pyrgulopsis bernardina (Taylor, 1987)

Yaquicoccus bernardinus Taylor, 1987:34, fig. 16.—USDI, 1991b:58823. Pyrgulopsis cochisi Hershler in Hershler and Landye, 1988:41, figs. 25d, 30h-k, 33, 34.

DIAGNOSIS.—Shell narrowly conic, small, weakly umbilicate. Penial filament elongate, lobe absent. Penial ornament of centrally positioned dorsal and ventral glands.

DESCRIPTION.—Shell (Figure 9d) narrow-conic; height, 1.3–1.7 mm; whorls, 3.25–4.0. Protoconch weakly punctate, with several weak adapical spiral lines on later portion. Teleoconch whorls convex, shouldered; sculpture of weak-moderately strong growth lines. Aperture ovate, large, very narrowly adnate or slightly separated from body whorl. Inner lip complete, thin; columellar lip slightly reflected. Outer lip near orthocline. Umbilicus usually narrowly rimate. Periostracum light tan.

Operculum (Figure 9e,f) ovate, light amber; nucleus slightly eccentric; dorsal surface weakly frilled. Attachment scar margin moderately thickened between inner edge and nucleus and along most of inner edge; callus weak.

Central radular tooth (Figure 33a) with strongly indented dorsal edge; tooth face square; lateral cusps, 4–5, elongate; central cusp pointed, slightly longer than laterals; basal cusps, 1, elongate, with modest dorsal support. Basal process medium width; basal sockets deep. Lateral margins slightly thickened; neck moderate.

Cephalic tentacles pale. Snout pale to moderate gray-black. Foot usually pale, sometimes lightly pigmented along anterior edge. Opercular lobe black along inner edge, sometimes dark over entire surface. Neck pale. Pallial roof, visceral coil moderate-dark brown-black.

Ctenidial filaments, 14, short, narrow. Osphradium centrally positioned along ctenidial axis. Kidney opening slightly thickened. Stomach caecum very small.

Testis, 1.5 whorls, overlapping posterior stomach chamber. Prostate gland with short pallial section; pallial vas deferens without proximal kink. Penis (Figure 44a) medium-sized; filament slightly shorter than base, tapering; lobe absent. Dorsal penis bearing large horizontal gland borne on low stalk near distal edge. Ventral gland large, stalked, horizontal, positoned near distal edge of penis. Filament dark.

Female genitalia shown in Figure 4d. Ovary, 0.5 whorl, abutting or very slightly overlapping posterior edge of stomach. Pallial albumen gland short. Capsule gland as long as albumen gland. Genital aperture a terminal slit with short vestibule. Coiled oviduct a small, tightly circular loop. Oviduct and bursal duct join just behind pallial wall. Bursa copulatrix globular, short, broad, with about half of length posterior to gland. Bursal duct very narrow, elongate (300%), positioned dorsal to coiled oviduct, shallowly embedded in albumen gland. Seminal receptacle finger-like, long (57%), pressed against posterior edge of oviduct lateral to distal bursal duct (well anterior to bursa copulatrix).

TYPE LOCALITY.—Pyrgulopsis bernardina: Spring 2,300 ft E, 4,600 ft S of NW corner, sec. 15, T 24S, R 30E, Cochise County, Arizona. Holotype, LACM 2186; paratypes, ANSP 376019, FSM 160934, USNM 854078, USNM 854088. Pyrgulopsis cochisi: Spring at San Bernardino Ranch, Cochise County, Arizona. Holotype, USNM 859055; paratypes, USNM 859056.

DISTRIBUTION.—Restricted to type locality area (two springs on San Bernardino Ranch), southeast Arizona, Rio Yaqui drainage.

MATERIAL EXAMINED.—USNM 847218 (topotypes, cochisi).

Pyrgulopsis cochisi Hershler

San Bernardino springsnail

Fontelicella species.—Williams et al., 1985:50.

MATERIAL EXAMINED.—ARIZONA. Cochise County: Springs at San Bernardino Ranch, USNM 859055 (holotype), 859056 (2 paratypes), 847218, J.J. Landye, 20 Mar 1971.

DIAGNOSIS.—A small size species (1.3 to 1.7 mm) having ovate-conic shell. Penis moderate size, without lobe; filament elongate. Dorsal and ventral penial surfaces each with single glandular ridge. Holotype (Figure 31h) height, 1.55 mm; width, 1.04 mm; whorls, 3.5.

DESCRIPTION.—Shell (Figure 32h–k) with 3.25 to 4.0 slightly convex whorls, with sutures only very slightly indented. Sexual dimorphism significant (females larger than males). Inner lip thin. Umbilicus open.

Snout with light to dark dusting of pigment. Sides of head/foot somewhat less pigmented than snout, although operculigerous lobe often quite dark. Penial filament darkly pigmented along entire length.

Ctenidial filaments, 12 to 15. Anterior portion of central tooth with few cusps (4-1-4) (Figure 34). Inner and outer marginals with roughly same number of cusps (Table 2). Prostate 11% of body length. Penis fairly elongate (Figure 35). Penial filament 61% of penis length, extending distal to anterior tip of penis. Filament three times as long as wide. Glandular ridges, two. Ridges positioned just proximal to base of filament. Capsule gland slightly longer (108%) than albumen gland. Seminal receptacle body minute, length of receptacle (body plus duct) 67% of bursa length.

DISTRIBUTION.—Restricted to type-locality and nearby small seeps at San Bernardino Ranch.

ETYMOLOGY.—Named after Apache chief Cochise.

The San Bernardino springsnail (Pyrgulopsis bernardina) is an endangered species of freshwater snail in the family Hydrobiidae. This species is endemic to a small number of springs in the USA and northern Mexico.