Fluminicola virens (Lea 1838)

Fluminicola virens (Lea, 1838)

Paludina virens Lea, 1838:91, pl. XXIII: fig. 93 [lectotype: USNM 121431, selected herein; type locality: Wahlamat (sic) (River), near its junction with the Columbia River].—Frauenfeld, 1864:659.

Paludina nuclea Lea, 1838:91, pl. XXIII: fig. 103 [type not located; type locality: Wahlamat (sic) (River), near its junction with the Columbia River.—Haldeman, 1847:5 [as synonym of L. virens].—Carpenter, 1857:207, 297.—Brot, 1862:26 [as synonym of L. virens].—Frauenfeld, 1864:630 [as synonym of P. virens].—Binney, 1865:91 [as synonym of F. virens],—Pilsbry, 1899a:123 [as synonym of F. virens].—Dall, 1905:119 [as synonym of F. virens].—Hannibal, 1912:187 [as synonym of F. virens].—Henderson, 1929:169 [as synonym of F. virens].

Leptoxis virens.—Haldeman. 1847:5, pl. 5: figs. 147–150.—Binney, 1859:12; 1860:11.—Brot, 1862:26.

Bithinia nuclea.—Carpenter, 1857:326.—Binney, 1859:13.

Vivipara nuclea.—Binney. 1859:12 [as synonym of L. virens].

Vivipara virens.—Binney, 1859:13.

Anculosa nuclea.—Tryon, 1864b: 104.

Anculosa virens.—Tryon, 1864b: 104.

Fluminicola nuclea.—Stimpson, 1865a:53: 1865b:54.

Fluminicola virens.—Binney, 1865:91–92.—Stimpson, 1865a:53; 1865b:54.—J.G. Cooper. 1867:30.—Tryon, 1870:65, pl. 17: fig. 18 [in part].—Pilsbry, 1899a:122–123 [in part].—Orcutt, 1901a:35–36 [in part]; 1902?:61–62 [in part].—Dall, 1905:119 [in part].—Hannibal, 1912:187 [in part].—Henderson. 1929:169 [in part]; 1936b:277 [in part].—La Rocque, 1953:271 [in part].—Burch and Tottenham, 1980:102–103, fig. 145 [in part].—Turgeon et al., 1988:61.

Lithoglyphus virens.—Taylor, 1966b:160; 1975a:205.—Clarke, 1981:70 [in part].

Lithoglyphus nucleus.—Taylor, 1975a: 131.

Fluminicola nuttalliana.—Thompson. 1984:140 [in part].

DIAGNOSIS.—Large with ovate- to narrow-conic shell; penis large, broadly triangular.

This species is phylogentically distinct from the clade comprising all other species allocated to Fluminicola, and it is set apart by various unique features (within the genus), including unpigmented ganglia, short pedal commissure, vas deferens coiled on neck, broadly triangular penis, penis deeply folded along almost entire length, terminal papilla on penis, simple, posterior oblique coiled oviduct, absence of secondary storage of sperm in coiled oviduct, subglobular bursa copulatrix, extremely long bursal duct, and large seminal receptacle.

DESCRIPTION.—Shell (Figures 13E,F, 15G–N) ovate- to narrow-conic, usually with eroded spire; height 5.8–12.0 mm; whorls 4.5–5.0. Protoconch (Figure 6I) of 1.5 whorls, diameter about 0.85 mm; microsculpture of numerous strong spiral striae. Teleoconch whorls flat to slightly convex; shoulders very narrow or absent. Microsculpture of fine collabral growth lines. Periostracum light tan, yellow, or green. Shell opaque, grey white. Aperture of medium size, ovate, strongly angled above. Outer lip weakly sinuate, usually thick. Parietal lip complete, usually thick, broadly adnate, sometimes slightly expanded over body whorl. Columellar lip of medium thickness, columellar swelling narrow to medium wide. Shell usually anomphalous; umbilical region sometimes narrowly excavated, with adaxial ridge.

Operculum (Figure 16C) of medium thickness; outer margin with very weak rim. Attachment-scar margin slightly thickened, stronger along inner edge. Callus weak but with pronounced narrow thickening extending to outer side of nucleus.

Radula (Figure 17G–I) with about 78 rows of teeth; ribbon length 1.84 mm, ribbon width 0.2 mm; central tooth width 59 µm. Central tooth with pronounced dorsal indentation; lateral cusps 4–5; median cusp narrowly U-shaped, slightly broader and longer than laterals; basal cusps 2–3, elongate; basal tongue medium wide, basal sockets strongly excavated; lateral angles slightly thickened. Lateral tooth with slightly concave dorsal edge; dorsal edge about 50% of tooth width; lateral shaft considerably longer than height of tooth face; tooth face about as tall as wide; central cusp narrowly U-shaped, lateral cusps 3 (inner side) or 4 (outer side). Inner marginal teeth with 13–14 cusps; outer marginal teeth with 15–16 cusps.

Snout grey black; distal lips pale. Tentacles with black, central, longitudinal band extending from eyes nearly to distal tip, otherwise pale except for internal grey pigment at base. Head grey. Foot pale to light grey. Pallial roof grey black. Visceral coil nearly colorless to medium grey.

Ctenidium overlapping pericardium; filaments about 39, tall, pleated. Osphradium almost 50% of ctenidium length. Hypobranchial gland swollen on proximal genital duct. Fecal pellets longitudinal. Renal organ swollen; renal opening white. Salivary glands overlapping cerebral ganglia. Stomach slightly longer than style sac. Pedal commissure less than 25% of ganglia width. Ganglia unpigmented.

Testis 1.5 whorls, overlapping posterior stomach chamber, filling 50%–67% of visceral coil behind stomach chamber. Prostate gland with 33% of length in pallial roof, fat. Vas deferens nearly straight in pallial roof, coiled in a series of tight loops in neck. Penis (Figure 9G) large, broad, flattened, slightly curved (but uncoiled), with strong folds along entire length except distal tip (Figure 1G); base slightly narrowed; medial section weakly tapering; distal section strongly tapering, with rounded tip bearing eversible papilla (Figure 1H). Penial duct central, narrow, tightly coiled in basal and medial sections. Penis without epithelial pigment; two broad, dark bands of black subepithelial pigment flanking penial duct.

Ovary 0.5 whorl, abutting posterior edge of stomach, filling about 50% of visceral coil behind stomach. Distal female genitalia shown in Figure 18C. Coiled oviduct narrow, posterior oblique, unpigmented; proximal portion rarely with small kink. Coiled oviduct and bursal duct join just behind pallial wall. Bursa copulatrix about 33% of albumen gland length, subglobular, about as long as wide, almost entirely overlapped by gland. Bursal duct as long as or slightly longer than bursa, originating from middle of long axis of organ. Seminal receptacle 40%–50% of bursa copulatrix length, positioned anterior to bursa copulatrix near middle of albumen gland, entirely overlapped by gland. Pallial gonoduct without rectal furrow. About 25% of albumen gland lying in front of posterior pallial wall. Capsule gland shorter, narrower than albumen gland. Ventral channel without anterior vestibule. Genital opening a subterminal pore.

DISTRIBUTION.—Willamette River (and large tributary streams), from Corvallis to its mouth, and the lower Columbia River below Portland (Figure 14).

MATERIAL EXAMINED.—OREGON. Wahlamette [sic], USNM 121432, USNM 860649 (paralectotypes, P. virens Lea). Willamette River, ANSP 27755, ANSP 27756, ANSP 27765, USNM 28115, USNM 99303 (mixed with F. fuscus), USNM 121431 (lectotype, P. virens Lea). Portland, ANSP 27761 (mixed with Fluminicola sp.), ANSP 113137, USNM 473989, USNM uncat. (Lea 1379). Corvallis, USNM 531629. Clackamas River, CAS 93810. Clackamas County: Canal or flume from Tualatin River to Oswego Lake, ANSP 111291 (mixed with Fluminicola sp.). Willamette River, Oregon City, ANSP 73605, USNM 511059 (mixed with Fluminicola sp.). Oswego, USNM 511057 (mixed with Fluminicola sp.). Willamette River, Canby Ferry (north side), USNM 883673*, USNM 883779*. Willamette River, Bernert Landing (on Clackamas-Linn County line) (mixed with Fluminicola sp.), USNM 883670*. Willamette River (south side), river mi 34.9 (km 56.2), Molalla State Park, USNM 883461. Willamette River (south side), river mi 40.9 (km 65.8), French Prairie State Park, USNM 883183*, USNM 883692*. Linn County: Willamette River, Albany, USNM 883676 (mixed with Fluminicola sp.). Multnomah County: Near Portland, CAS 93814.

WASHINGTON. Cowlitz County: Columbia River, Abernathy Point, just east of mouth of Abernathy Creek, USNM 883463*, USNM 883693*.