Tag: Ellobiidae

• Saraphia tridentata Risso 1826: 84.

Identification. Shell minute, fusiform, thin-shelled. Spire more elongate than Carychium minimum, sides rather convex. Whorls c. 5. Apex bluntly rounded. Suture deep. Periphery rounded. Protoconch smooth. Teleoconch with weak incremental striae initially, regular, colabral striae on last 2 whorls. Aperture subovate; c. 2/5 of shell height, with 1 larger parietal lamella that continues internally around columella in a smooth curve, 1 weakly formed lamella at base of columella that may be lacking. Lip expanded, thickened, with a strongly projecting, medial callus on inside. Peristome, viewed from side: prosocline, strongly sinuous; belly of last whorl projecting beyond the plane of peristome. Parietal callus glazed, transparent, inconspicuous. Shell colourless or translucent white; with a silken sheen. Shell height to 2.0 mm (higher than wide).

Animal white with black eyespots. The animal has two conical-cylindrical tentacles; ocular tentacles are absent, and the eyes are located at the base of the tentacles. The narrow foot is not divided into two longitudinal sections as is typical for many marine ellobiids (Watson & Verdcourt 1953) and the anterior is bilobed. The male and female genital openings are separate on the right side, with the male genital pore just in front of the right tentacle and the female genital pore towards the base of the neck.

This species is most like C. minimum, but it is recognized by its greater number of whorls, longer spire, and smoothly curved internal lamella.

Habitat. In BC,C. tridentatum is only known from a city park, where it has been found in leaf litter of an unkempt garden of mature trees and shrubs (Forsyth and Williston 2012).

Geographic range. Native to the Western Palaearctic. In BC, this species is known only from Queen Elizabeth Park, Vancouver (Forsyth and Williston 2012; Weigand et al. 2012).

Etymology. Carychium, from the Greek karyx, a herald, signifying the ancient use of a shell as a trumpet (Kennard & Woodward 1926); the gender is neuter. Tridentatum (Latin), three-toothed.

Remarks. The identification of BC specimens was confirmed by molecular analysis (Weigand et al. 2012).

References

Forsyth RG, Williston P (2012) Terrestrial snails from an urban park in Vancouver, British Columbia. The Festivus 44: 77–80.

Kennard AS, Woodward BB (1926) Synonymy of the British non-marine Mollusca (Recent and post-Tertiary). British Museum (Natural History), London, United Kingdom, xxiv + 447 pp. https://doi.org/10.5962/bhl.title.8325

Risso A (1826) Histoire naturelle des principales productions de l’Europe méridionale et pariculièrement de celles des environs de Nice et des Alpes Maritimes. Tome quatière. F.-G. Levrault, Paris, France, viii + 439 pp., 12 pls. pp. https://doi.org/10.5962/bhl.title.58984

Watson H, Verdcourt B (1953) The two British species of Carychium. Journal of Conchology 23: 306–324, pls 9, 10. Weigand AM, Pfenninger M, Jochum A, Klussman-Kolb A (2012) Alpine crossroads or origin of genetic diversity? Comparative phylogeography of two sympatric microgastropod species. PLoS ONE 7: e37089. https://doi.org/10.1371/journal.pone.0037089

• Carychium exiguum var. occidentalis [sic] Pilsbry 1891a: 109, without gender agreement; with gender corrected: occidentale.
• Carychium magnificum Hanna 1923: 51, fig. 1.

Identification. Shell minute, fusiform, thin-shelled. Spire elongate, sides rather straight. Whorls c. 5. Apex bluntly rounded. Suture deep. Periphery rounded. Protoconch smooth. Teleoconch smoothish, with weak colabral striae. Aperture subovate; c. ⅓ of shell height, with 1 larger parietal lamella that continues internally around columella in a smooth curve, 1 weakly formed lamella at base of columella that may be lacking. Lip expanded, edge thin, seldom with a low, medial callus on inside. Peristome, viewed from side: prosocline, not strongly sinuous; belly of last whorl not projecting beyond the plane of peristome. Parietal callus glazed, transparent, inconspicuous. Shell colourless or translucent white; with a silken sheen. Shell 2.0–2.7 mm high (higher than wide).

Animal white with black eyespots.

This is the largest Carychium species in BC, further distinguished by its clearly tapering spire, weakly sculptured shell, and thin, but expanded, palatal lip.

Habitat. This species occurs in relatively undisturbed deciduous and mixed lowland forests at and below 80 m elevation. Bigleaf Maples (Acer macrophyllum Pursch) are usually present. It is found mostly in deep-litter areas, in hollows, near seeps, and in riparian zones that are perpetually moist but not overly wet. Colonies are scattered and patchy in their distribution.

Geographic range. BC, south to northern California where it occurs in the coastal counties of Del Norte, Humboldt, and Mendocino (Roth and Sadeghian 2003); east through northern Washington and possibly in the Idaho Panhandle (Frest and Johannes 2001).

In BC, C. occidentale occurs along the coast from at least the northern end of Vancouver Island south. It is expected for wet areas of the south-eastern interior, although not found there in the extensive surveys by Ovaska et al. (2020). Union Bay, Vancouver Island (Hanna 1923), is the type locality of C. magnificum, a synonym of C. occidentale (Pilsbry 1948).

Etymology. Carychium, from the Greek karyx, a herald, signifying the ancient use of a shell as a trumpet (Kennard & Woodward 1926); the gender is neuter. Occidentale (Latin), western.

Remarks. Carychium occidentale was first described as new by Pilsbry (1891a) from Portland, Oregon, the only locality from which he had seen this species. In the original description, Pilsbry wrongly spelled the species occidentalis, a mismatch of the gender with that of the genus.

In 1916, G Dalla Hanna (1923) briefly visited Vancouver Island where he collected land snails. Among those found at Union Bay were specimens of Carychium which he described as C. magnificum on account of their impressively large size. Hanna thought that his C. magnificum was a larger species, different from C. occidentale, although “undoubtedly closest related” (Hanna 1923: 52). Shortly thereafter, Pilsbry commented that it is “larger than one of the type lot of C. occidentale, and appears to resemble that in shape and internal lamellæ” (Pilsbry 1923: 141), but Hanna’s C. magnificum was soon subjugated to the synonymy of the earlier C. occidentale.

Early records of C. exiguum from Vancouver Island (e.g. Taylor 1889), which pre-date Pilsbry’s description of C. occidentale, are almost certainly this species.

References

• Hanna GD (1923) A new species of Carychium from Vancouver Island, British Columbia. Proceedings of the California Academy of Sciences (Series IV) 12: 51–53.
• Roth B, Sadeghian PS (2003) Checklist of the land snails and slugs of California. Santa Barbara Museum of Natural History Contributions in Science 3: 1–81.
• Frest TJ, Johannes EJ (2001 “2000”) An annotated checklist of Idaho land and freshwater mollusks. Journal of the Idaho Academy of Science 36: 1–51.
• Kennard AS, Woodward BB (1926) Synonymy of the British non-marine Mollusca (Recent and post-Tertiary). British Museum (Natural History), London, United Kingdom, xxiv + 447 pp. https://doi.org/10.5962/bhl.title.8325
• Taylor GW (1889) The land shells of Vancouver Island. The Ottawa Naturalist 3: 84–94.
• Pilsbry HA (1923) A new species of Carychium from Vancouver Island. The Nautilus 36: 141.
• Ovaska K, Sopuck L, Heron J (2020 “2019”) Surveys for terrestrial gastropods in the Kootenay region of British Columbia, with new records and range extensions. The Canadian Field-Naturalist 133: 221–234. https://doi.org/10.22621/cfn.v133i3.2287
• Pilsbry HA (1891) Forms of American Carychium. The Nautilus 4: 109–110.

• Auricula myosotis Draparnaud 1801: 53.
• Many more synonyms worldwide.

Identification. Shell elongate-ovate. Spire tall, with sides straight or scarcely convex. Apex acutely pointed. Suture rather shallow. Whorls c. 7, not very convex in profile. Periphery rounded, medial. Protoconch smooth, but most often eroded. Teleoconch with first three whorls deeply pitted in spiral rows, then smoothish or with irregular, often quite strong growth wrinkles; particularly when shell eroded, low colabral riblets often evident; occasional varix present at site of growth rest. Juveniles and occasionally well-preserved adults with 1 spiral row of well-spaced periostracal hairs (which correspond to the pits). Aperture subovate-elongate, acutely angled above, c. 70% of shell height, with 1 strong, medial parietal plica, 1 strong columellar plica, and 1 low, callus-like protuberance (usually absent) above; plicae white. No palatal lirae in BC specimens, although 1 or more are reported elsewhere (Frias Martins 1996). Lip expanded when mature but generally thin. Parietal callus glazed, transparent, inconspicuous. No umbilicus. Shell weakly glossy, yellowish or more frequently reddish brown; lip pale. Height to 8.4 mm (higher than wide).

Animal greyish-white, darker, blackish anteriorly and dorsally and on tentacles; sole of foot yellowish grey. Blackish eye spots at the base of tentacles. Foot yellowish.

Comparison. This species is unlike any other snail in BC, where it is the only semimarine ellobiid. This semi-marine salt-marsh snail is included here to complete the family Ellobiidae.

Habitat. Myosotella myosotis inhabits the semimarine supralittoral zone along the coast, in salt marshes of sheltered bays and occasionally along the strand line where salt marshes are absent. Snails are usually gregarious in damp places under driftwood and other debris, living plants such as pickleweed (Salicornia L.), and washed up, dislodged eelgrass (Zostera L.). They also live in loose soil and occasionally among stones.

Biology. Snails can survive fully submerged for weeks, and they are tolerant of a broad range of salinity, although normal development of eggs is possible only at lower salinity. Eggs are deposited in masses on the substrate and develop in about 18 days (Seelemann 1968).

The diet includes bacteria, cyanobacteria, diatoms, and outer cells of salt-marsh vegetation (Seelemann 1968; Berman and Carlton 1991).

In experiments to test if the establishment of the invasive M. myosotis in the Northeast Pacific came at the expense of native salt-marsh snails Angustassiminea californica (Tryon, 1865) and Littorina subrotundata (P.P. Carpenter, 1864), Berman and Carlton (1991) found that it did not.

Geographic range. Myosotella myositis is introduced to BC. It was first reported from the province by Grass (1967) as Alexia myosotis. In BC, it is known from around the Strait of Georgia in suitable habitat, north to at least Union Bay, on the east coast of Vancouver Island. This species is native to the Mediterranean and eastern Atlantic coasts.

All North American occurrences of M. myosotis, BC south to California and Nova Scotia to Cuba, are introductions, and it has also been introduced to Bermuda, the Azores and Madeira, South Africa, South Africa, and Australia (Frias Martins 1996). The wide distribution to many places worldwide is probably due to being transported in ships’ ballast or cargo (Climo 1982).

Etymology. Myosotella: derived from the species epithet with the addition of the Latin diminutive suffix ­-ella; the gender is feminine. Myosotis: from the Greek myos, mouse + otis, ear, a reference to the shape of the shell.

Remarks. In the literature, M. myosotis has variously been placed in Alexia Leach, 1847, “Phytia“, or Ovatella Bivona e Bernardi, 1832 (among others), but Myosotella is used instead of Ovatella for this species following Frias Martins (1996, 1999), based on morphology of the shell and anatomy. The many introductions to many places worldwide have resulted in an extensive synonymy (Frias Martins 1996). However, anatomical and molecular data of this species from various places worldwide have shown unsuspected genetic diversity in what has been known as M. myosotis (Frias Martins and Marques Mendes 2013).

References

• Berman J, Carlton JT (1991) Marine invasion processes: interactions between native and introduced marsh snails. Journal of Experimental Marine Biology and Ecology 150: 267–281.
• Climo FM (1982) The systematic status of Auricula (Alexia) meridionalis Brazier, 1877 and Rangitotoa insularis Powell, 1933 (Mollusca: Ellobiidae) in Australasia. National Museum of New Zealand Records 2: 43–48.
• Draparnaud J (1801) Tableau des Mollusques terrestres et fluviatiles de la France. Renaud & Bossange, Masson & Besson, Montpellier & Paris, 116 pp.
• Frias Martins AM de (1996) Anatomy and systematics of the Western Atlantic Ellobiidae (Gastropoda: Pulmonata). Malacologia 37: 163–332.
• Frias Martins AM de (1999) On the generic separation of Ovatella Bivona, 1832 and Myosotella Monterosato, 1906 (Pulmonata: Ellobiidae). Iberus 17: 59–75.
• Frias Martins AM de, Marques Mendes AR (2013) Do cosmopolitans speciate? Anatomical diversity of Myosotella in Azores. World Congress of Malacology 2013, Azores. https://doi.org/10.13140/2.1.3483.4564
• Grass AL (1967) Alexia myosotis (Ellobiidae) in British Columbia. The Canadian Field-Naturalist 81: 278–279. https://doi.org/10.5962/p.342814
• Seelemann U (1968) Zur Überwindung der biologischen Grenze Meer—Land durch Mollusken. Untersuchungen an Alderia modesta (Opisth.) und Ovatella myosotis (Pulmonat.). Oecologia 1: 130–154.

• Carychium minimum O.F. Müller 1773 (1773–1774): 125.
• Other synonyms in older European literature.

Identification. Shell obese-fusiform. Spire elongate, with strongly convex sides. Apex bluntly pointed. Whorls c. 4, convex. Sutures rather well indented. Protoconch smooth. Teleoconch with weak incremental striae initially, regular, colabral striae on last two whorls. Aperture subovate; 1 parietal lamella, continuing internally around columella in a smooth, not undulating curve; 1 smaller lamella at base of columella. Adult lip expanded, a little recurved, thickened on inner side, especially medially on palatal lip. Belly of the last whorl projected beyond the plane of peristome. Chink-like “false umbilicus” against base of last whorl. Shell translucent, colourless when fresh, opaque, and white when dead. Shell to 1.9 mm high (higher than wide).

The animal’s body in unpigmented, white, with black eye spots behind the single pair of cylindrical tentacles (Adam 1960; Roth 1982).

Comparison. Among Carychium species in BC, this species is recognized by its faintly striate, stouter shell, having fewer whorls and a greatly thickened palatal lip which bears a prominent medial denticle. The aperture is relatively larger portion of the shell height than in the other Carychium species in BC. The internal lamella is regularly spiral, which is not the case inC. tridentatum.

Habitat. This species lives in permanently wet habitats. In BC, in occurs in dead vegetation and under driftwood and logs along the tidal shoreline of the Fraser River, and it was found under flowerpots and other objects in a well-watered garden centre on Vancouver Island (Forsyth 2004b). It should be expected in wet areas of gardens, such as found in the tree-fern garden in Golden Gate Park, San Francisco, California (Roth 1982). At Ithaca, New York, populations were in a seep near a lake and in the riparian zone of a creek (Weigand & Jochum 2010).

In Europe, typical habitats of C. minimum include edges of swamps and in wet woods, floodplain meadows, and dune slacks (Germain 1931; Kerney 1999), and this species occurs at elevations up to 1,000 m in the Alpes (Germain 1931). Geographic range. Native to the Western Palaearctic. Introduced to BC, this species was first found in a nursery in Cobble Hill, Vancouver Island (Forsyth 2004b). Only later, was it discovered living naturalised along the Fraser River estuary in Richmond (Forsyth 2015). It is expected that this species occurs more generally in suitably wet habitats in BC. Elsewhere in Canada,C. minimum has been introduced to Ontario (Grand River, Brant County; Port Whitby, Durham Region) and New Brunswick (Mactaquac Lake, a broadening of the Saint John River) (Forsyth 2015; unpublished data); it has also been reported from California (Roth 1982), New York (Forsyth 2015; Weigand & Jochum 2016); Massachusetts (Clapp 1912; Winslow 1922), and Pennsylvania (Pearce and Payne 2011). It is likely more widely occurring in North American than presently known

Etymology. Carychium, from the Greek karyx, a herald, signifying the ancient use of a shell as a trumpet (Kennard & Woodward 1926); the gender is neuter. Minimum (Latin), least or smallest.

Remarks. In much of the older European literature, C. minimum and C. tridentatum were not distinguished from each other, or with the latter treated as a variety of the former; Watson & Verdcourt (1953) reviewed the history the use of these names. However, in the recent literature, these taxa have generally been treated as separate species, and this has been confirmed DNA barcoding by Weigand et al. (2010).

In another study, Weigand et al. (2012) investigated the population structure of C. minimum and found in Europe four distinct, genetically isolated phylogenetic units which are likely explained by refugial areas during glacial periods; a population in eastern North America was found to belong to the Central–Western Europe clade.

References

• Adam W (1960) Mollusques. Tome 1, mollusques terrestres et dulcicoles. Institut Royal des Sciences Naturelles de Belgique, Bruxelles, 402 pp., 4 pls.
• Clapp W (1912) Carychium minimum Mull. The Nautilus 26: 24.
• Forsyth RG (2004) Land Snails of British Columbia. Royal BC Museum, Victoria, BC, Canada, iv, 188 pp.
• Forsyth RG (2015) First record of Carychium minimum Müller, 1774 in New Brunswick, Canada (Mollusca: Gastropoda: Ellobioidea). Check List 11: 1511. https://doi.org/10.15560/11.1.1511
• Germain L (1931) Faune de France 22. Mollusques terrestres et fluviatiles (deuxième partie). Paul Lechavalier, Paris, France, 479-897, i-xiv, pls 1-26 pp.
• Kennard AS, Woodward BB (1926) Synonymy of the British non-marine Mollusca (Recent and post-Tertiary). British Museum (Natural History), London, United Kingdom, xxiv + 447 pp. https://doi.org/10.5962/bhl.title.8325   
• Kerney M (1999) Atlas of the land and freshwater molluscs of Britain and Ireland. Harley Books, Colchester, United Kingdom, 264 pp.
• Müller OF (1774) Vermium terrestrivm et fluviatilium, seu animalium infusorium, helminthicorum, et testaceorum, non marinorum, succincta historia. Volumen alterum: testacea. Heineck & Faber, Havniæ & Lipsiæ, xxxvi + 214 + [x] pp. https://doi.org/10.5962/bhl.title.46299
• Pearce TA, Payne SL (2011) European Carychium land snails in Pennsylvania. Tentacle 19: 13.
• Roth B (1982) European land mollusks in the San Francisco Bay area, California: Carychium minimum Müller and the Arion hortensis complex. The Veliger 24: 342–344.
• Watson H, Verdcourt B (1953) The two British species of Carychium. Journal of Conchology 23: 306–324, pls 9, 10.
• Weigand AM, Jochum A, Pfenninger M, Steinke D, Klussman-Kolb A (2010) A new approach to an old conundrum—DNA barcoding sheds new light on phenotypic plasticity and morphological stasis in microsnails (Gastropoda, Pulmonata, Carychiidae). Molecular Ecology 11: 255–265. https://doi.org/10.1111/j.1755-0998.2010.02937.x
• Weigand AM, Jochum A (2016) Mollusca, Gastropoda, Ellobioidea, Carychium minimum O.F. Müller, 1774: filling gaps. New population record for the State of New York, Northeastern United States. Check List 6: 517–518. https://doi.org/10.15560/6.4.517
• Winslow ML (1922) Notes on the internal lamellae of Carychium. Occasional Papers of the Museum of Zoology, University of Michigan 128: 1–17.