Extensive diversification of pebblesnails (Lithoglyphidae: Fluminicola) in the upper Sacramento River basin, northwestern USA Author Hershler, Robert Author Liu, Hsiu-Ping Author Frest, Terrence J. Author Johannes, Edward J. text Zoological Journal of the Linnean Society 2007 2007-03-31 149 3 371 422 https://academic.oup.com/zoolinnean/article-lookup/doi/10.1111/j.1096-3642.2007.00243.x journal article 10.1111/j.1096-3642.2007.00243.x 0024-4082 5428601 FLUMINICOLA MULTIFARIUS SP. NOV. (SHASTA PEBBLESNAIL) Type material: Holotype ( Fig. 24A ), USNM 883782 , Big Springs (source) at Big Springs City Park northwest of the city of Mount Shasta , south of Spring Hill , Siskiyou County , California (556400 E, 4575265 N, 1092 m ), 25 May 1991 TF , EJ . Paratypes (from same lot), USNM 1020753 . Referred material: CALIFORNIA . Siskiyou County : USNM 1020754 , topotypes, 12 October 1992 TF , EJ . – USNM 1020755 , topotypes, 23 August 2001 TF , EJ . – USNM 1020756 , Ney Springs on the north side of Ney Springs Road , north tributary of Ney Springs Creek , east of Faery Falls , south-west of the city of Mount Shasta (556120 E, 4568040 N, 964 m ), 12 October 1992 TF , EJ . – USNM 1020757 , ibid., 23 August 2001 TF , EJ . – USNM 1020758 , Sacramento River on the north side, just upstream and opposite from the mouth of Stink Creek , at former site of USGS gauging station, just west (upstream) of the site of Cantara ( Cantara Bend ), near the end of Cantara Road , Cantara / Ney Springs Wildlife Area ( California Fish and Game ) (557860 E, 4568220 N, 915 m ), 13 October 1992 TF , EJ . – USNM 1020759 , ibid., 21 September 1996 TF , EJ . – USNM 1020760 , ibid., 17 August 2000 TF , EJ . – USNM 1020761 , unnamed spring above north side of Sacramento River , ditched on north side of UPRR track, tributary (west side) to first permanent creek west of Big Canyon Creek , east of Cantara Bend ( Cantara town site) (559160 E, 4568405 N, 885 m ), 6 September 1993 TF , EJ . – USNM 1020762 , ibid., 1 October 2001 TF , EJ . – USNM 1020763 , unnamed spring above sharp bend in Sacramento River (north side), collected on north side of UPRR track, east of Cantara Bend ( Cantara town site) (558820 E, 4568560 N, 878 m ), 6 September 1993 TF , EJ . – USNM 1020764 , ibid., 1 October 2001 TF , EJ . – USNM 1020765 , Big Springs three middle runs upstream of wooden bridges of access trail, c . 31 m west of eastern-most spring run, Big Springs City Park north-west of the city of Mount Shasta , south of Spring Hill (556370 E, 4575265 N, 1092 m ), 23 August 2001 TF , EJ . – USNM 1020766 , Big Springs westernmost run upstream of wooden bridge of access trail, c . 61 m west of eastern-most spring run and 31 m west of three middle spring runs, south of Spring Hill on west edge of Big Springs City Park north-west of the city of Mount Shasta (556330 E, 4575280 N, 1092 m ), 23 September 1996 TF , EJ , JL . – USNM 1020767 , ibid., TF , EJ , JL . – USNM 1020768 , Big Springs east spring run downstream of wooden bridge of access trail, c . 31 m south of source springs, Big Springs City Park northwest of the city of Mount Shasta , south of Spring Hill (556390 E, 4575240 N, 1092 m ), 23 August 2001 TF , EJ . – USNM 1020769 , west spring run of Big Springs on west side of Big Springs City Park , collected approximately 61 m below spring sources, north-west of the city of Mount Shasta , south of Spring Hill (556350 E, 4575220 N, 1089 m ), 23 August 2001 TF , EJ . – USNM 1020771 , Bundoora Spring c. 0.16 km west of Tom Cabin Spring and ruins of Tom’s Cabin , west of access road off FS40N44 c. 0.48 km west of Camp 4, Shasta National Forest (584400 E, 4564900 N, 1083 m ), 30 September 2001 TF , EJ . – USNM 1020801 , Lower Elk Spring , at spring house (577223 E, 4572303 N, 1179 m ), 4 November 2004 AH. – USNM 1020802 , ibid., 21 December 2004 JC. – USNM 1020803 , Elk Spring , outflow channel (577316 E, 4572190 N, 1172 m ), 21 December 2004 JC. – USNM 1020772 , spring flowing under UPRR tracks (source on west side of tracks), collected on both sides of tracks, west of Sacramento River , opposite mouth of Sweetbrier Creek , near the former site of Conant (556720 E, 4551100 N, 561 m ), 25 August 2001 TF , EJ . – USNM 1020773 , Crystal Spring near its source (which is now a covered well) on west-facing slope above the Sacramento River , above bridge of Zig Zag Trail , Shasta Springs , St. Germain Foundation (561580 E, 4566360 N, 854 m ), 17 October 1992 TF , EJ . – USNM 1020774 , ibid., 25 August 2001 TF , EJ . – USNM 1020775 , 1020776 , Rock Spring above (east of) UPRR tracks, above Sacramento River (east side), Shasta Springs (561580 E, 4566200 N, 769 m ), 17 October 1992 TF , EJ . – USNM 1020777 , 1020778 , ibid., 24 August 2001 TF , EJ . – USNM 1020779 , fourth spring from the north at the lower (downstream) end of Shasta Springs complex, east side of the Sacramento River above UPRR track (561560 E, 4566000 N, 756 m ), 21 October 1992 TF , EJ . – USNM 1020780 , 1020781 , 1020782 , 1020792 , ibid., 24 August 2001 TF , EJ . – USNM 1020800 , springs north of Mossbrae Falls on a west-facing slope, east side of the Sacramento River above UPRR track near the north end of railroad bridge (561520 E, 4565800 N, 756 m ), 21 October 1992 TF , EJ . – USNM 1020783 , ibid., 24 August 2001 TF , EJ . – USNM 1020784 , spring runs north of Mossbrae Falls on a west-facing slope, east side of the Sacramento River , near the east side of UPRR bridge (561560 E, 4565720 N, 769 m ), 21 October 1992 TF , EJ . – USNM 1020785 , ibid., 24 August 2001 TF , EJ . – USNM 1020786 , east side of the Sacramento River at Cave Springs below Cave Springs Resort and Motel , Dunsmuir ; 30 m transect north (upriver) from Cave Springs run (560710 E, 4564080 N, 724 m ), 24 August 2001 TF , EJ . – USNM 1020787 , ibid., 14 October 2003 TF , EJ . – USNM 1020788 , spring run north of Crystal Spring ( Glacier Spring ) run, north side of northern most switch back of Zig Zag Trail , Shasta Springs , Saint Germain Foundation (561520 E, 4566310 N), 25 August 2001 TF , EJ . Table 14. Shell parameters for Fluminicola scopulinus

WH	SH	SW	HBW	WBW	AH	AW
Holotype	3.5	2.78	2.52	2.37	2.11	1.52	1.40
Paratypes ( N = 18)	3.60	2.83	2.49	2.42	2.09	1.52	1.40
* N = 17	3.25–4.0*	2.56–3.42	2.31–2.77	2.22–2.89	1.90–2.37	1.41–1.81	1.29–1.55

Figure 24. Shells of Fluminicola multifarius . A, holotype (USNM 883782). B, USNM 1020754. C, USNM 1020756. D, USNM 1020757. E, USNM 1020758. F, USNM 1020762. G, USNM 1020764. H, USNM 1020765. I, USNM 1020766. J, USNM 1020768. K, USNM 1020769. L, USNM 1020771. M, USNM 1020772. N, USNM 1020774. O, USNM 1020775. P, USNM 1020776. Scales = 1.0 mm. Diagnosis: Readily distinguished from F. scopulinus , which also lives in the Sacramento River headwaters, by its smaller shell umbilicus and broader columellar lip. Distinguished from F. seminalis , which also lives in the McCloud River drainage, by its smaller size, more convex shell whorls, well-developed shell parietal lip, more numerous radular tooth cusps, and squatter penis. Description: Shell ( Figs 24 , 25A–K ; Table 15 ) usually subglobose to narrow conical; height, 2.30–4.64 mm ; whorls, 3.25–4.50. Protoconch 1.4 whorls, diameter approximately 0.82 mm ; spiral microsculpture often wavy or wrinkled near apex. Teleoconch whorls weakly to highly convex, often having weak subsutural angulation; shoulders usually absent or narrow, rarely broad. In some conical shelled populations, specimens had last 1.0 whorl loosened from body whorl, producing an almost scalariform appearance ( Figs 24P , 25D ). Aperture broadly ovate, often angled above. Parietal lip complete, thin or slightly thickened, usually adnate, sometimes slightly disjunct, lip usually forming callus. Columellar lip medium width, often covering all or most of umbilical region. Outer lip thin or slightly thickened, sometimes markedly so, prosocline, weakly sinuate. Shell usually anomphalous, sometimes narrowly rimate, rarely perforate. Periostracum tan, brown, or light green. Last 0.5 operculum whorl frilled ( Fig. 25L ). Central radular tooth approximately 41 µm wide, cutting edge convex, lateral cusps three to four; central cusp parallel-sided, rounded or weakly pointed; basal cusps one to two, basal tongue V- or U-shaped, even with lateral margin ( Fig. 25N ). Lateral tooth face broadly rectangular; central cusp rounded, lateral cusps three (inner), three to four (outer); outer wing flexed, medium length ( Fig. 25O ). Inner marginal teeth having 22–29 cusps ( Fig. 25M ). Outer marginal teeth having 23–33 cusps; basal wing rectangular ( Fig. 25M ). Head-foot dark brown, almost black. Ctenidium connected to pericardium by short, efferent branchial vessel; ctenidial filaments approximately 17, without pleats. Osphradium elongate, positioned opposite middle of ctenidium. Bursa copulatrix horizontal; ovate, pyriform or triangular; duct medium length. Seminal receptacle small or medium-sized, sometimes only partly overlapped by albumen gland. Glandular oviduct having well-developed rectal furrow. Capsule gland about as long as albumen gland. Genital aperture a simple pore or weak papilla. Penis mediumsized, fairly broad, tightly coiled, distal end pointed or papillate ( Fig. 7M ). Penis having dark brown or black patch of internal pigment concentrated distally, surface pigment very light. Penial duct positioned near outer edge, straight except for a few distal undulations. Table 15. Shell parameters for Fluminicola multifarius

WH	SH	SW	HBW	WBW	AH	AW
Holotype	*	3.5	3.04	3.21	2.53	2.07	2.00
Paratypes ( N = 15)	3.52	3.55	2.99	3.05	2.41	2.01	1.89
*spire eroded	3.5–3.75	3.19–3.71	2.86–3.19	2.83–3.23	2.28–2.57	1.86–2.20	1.70–2.03

Figure 25. Shells, opercula, and radula of Fluminicola multifarius . A, USNM 1020779. B, USNM 1020780. C, USNM 1020781. D, USNM 1020782. E, USNM 1020783. F, USNM 1020784. G, USNM 1020786. H, USNM 1020788. I, USNM 1020792. J, K, USNM 1020801. Scales = 1.0 mm. L, outer side of operculum (USNM 1020753). Scale = 100 µm. M, portion of radular ribbon (USNM 1020753). Scale = 20 µm. N, central radular teeth (USNM 1020753). Scale = 10 µm. O, lateral radular teeth (USNM 1020753). Scale = 10 µm. Distribution: Sacramento River headwater region (as far downflow as Conant), and a few sites in the upper reaches of the McCloud River drainage ( Fig. 20 ). Etymology: From New Latin multifarius , meaning in many places, or in various manners, and referring to the broad range of shell shape observed in this species. Remarks: As noted in the Results section, this species is composed of two distinct subclades that differ by 2.1–3.0% ( COI ) and 3.3–4.7% (cytb) and are allopatrically distributed, with one ranging from Shasta Springs to Conant along the Sacramento River and the other distributed in the Sacramento headwater region from Cantara Bend to Big Springs (north of the city of Mount Shasta) as well as in the upper McCloud River drainage. Marked shell variation, with shape ranging from subglobose to narrowly conic and the entire body whorl sometimes completely loosened from the coiling axis, was observed within both subclades and sometimes within individual populations. Distinct shell morphs (e.g. at site 65) collected in sympatry did not differ in sequences of either gene and also did not differ anatomically. On the basis of these observations and the morphological overlap described above, we chose to treat the two subclades as a single species at this time, although the evolutionary and taxonomic significance of the remarkable shell variation within this taxon merits additional study. F. multifarius was variably positioned relative to other species of clade C described herein in the phylogenetic analyses and differs from these by 2.6–4.6% ( COI ) and 6.4–10.3% (cytb). Populations of this species were referred to as Fluminicola n. sp. 1, Fluminicola n. sp. 3, Fluminicola n. sp. 4, and Fluminicola n. sp. 5 by Frest & Johannes (1993) .