Paralaoma servilis

Paralaoma servilis (Shuttleworth, 1852)
Pin-head Spot

  • Helix (Helicella) pusilla Lowe 1831: 46, pl. 5, fig. 17, non Helix pusilla Vallot, 1801 nec Fleming, 1828.
  • Helix servilis Shuttleworth 1852: 140.
  • Helix caputspinulae Reeve 1852 (1851–1854): pl. 133, fig. 818.
  • Helix conspecta Bland 1865: 163, fig. 7.
  • Tonites [sic; Zonites] diegoensis Hemphill in W. G. Binney 1892: 168, pl. 3, fig. 2 (Coan & Roth 1987).
  • Punctum conspectum var. pasadenae Pilsbry 1896: 21.
  • Punctum conspectum alleni Pilsbry in Pilsbry & Ferriss 1919: 326.
  • Many additional synonyms and possible synonym in many parts of the world; see Gittenberger et al. (2020).
Paralaoma servilis
Paralaoma servilis, Riverside Park, Smithers, British Columbia; width 2.2 mm (RGF 97.207.2238).

Identification. Shell depressed heliciform. Spire moderately elevated, conical. Sutures deep. Whorls ca 4, rounded, convex. Protoconch smoothish or with spiral striae. Teleoconch with narrow, widely spaced colabral riblets, weaker on base; with usually 5 or 6 colabral striae between riblets; colabral striae beaded by spiral striae. Aperture rounded-lunate, wider than high, edentulous. Last whorl slightly descending above. Lip thin, simple. Umbilicus ca ¼ shell width. Shell yellowish or brownish olive. Shell width to 2.4 mm (wider than high).

Habitat. Often disturbed habitats such as roadsides and in parks and gardens, but some sites are surprisingly remote and less disturbed. In leaf litter, under dead wood, and under rocks. Most often seen alive in cool weather.

Global range. Unalaska Island, Aleutian Islands, Alaska (Eyerdam 1933), south into Mexico (Smith et al. 1990); in the USA, east to Idaho and Montana (Burke 2013). Elsewhere, the list of places where it has been found is long. Caribbean: Jamaica and Cuba; Asia: Russia (Kurile Islands, Sakhalin, Primorsky, and southern Kamchatka), Tajikistan, possibly China, Azerbaijan, Turkey, Jordan, Israel, and Saudi Arabia; North Africa: Algeria and Morocco; Sub-Saharan Africa: Eritrea, Ethiopia, Kenya, Tanzania, Uganda, and possibly South Africa, Mozambique, Congo, and Malawi; Pacific Islands: Easter Island and possibly Hawaii; Atlantic Islands: Canaries, Cape Verdes, Azores, Madeira, and St Helena; Europe: UK and Scandinavia, south to the Iberian Peninsula, east to the Balkan Peninsula and Cypress (see Gittenberger et al. 2020 for more information and additional references).

The native range is rather questioned but generally it is thought to be native to New Zealand. However, Roth (1986) thought it native to North America, on account of the remoteness of some localities where it had been found.

Range in Canada. British Columbia: sporadic, over most of the province. Expected in the southern Yukon (but not yet found there).

Etymology. Latin, servilis, of a slave.

Remarks. This species has been known by several different names in recent years, and th full list of synonyms or possible synonyms is long (see Roth 1985, 1986, 1987, Gittenberger et al. 2020 and references therein). In the North American literature, the species was long known as Punctum conspectum. Pilsbry (1948), who knew the species as Punctum conspectum, recognized two subspecies in additional to the nominotypical subspecies: P. c. pasadenae (with the major riblets reduced or absent) and P. c. alleni (with the riblets larger and the spire rather higher than “typical” examples. Roth & Sadeghian (2003) included pasadenae as a synonym; it seems likely that alleni is as well.

References

  • Binney WG (1892) A fourth supplement to the fifth volume of the terrestrial air-breathing mollusks of the United States and adjacent territories. Bulletin of the Museum of Comparative Zoology at Harvard College 22: 163–204, pls 161–164.
  • Bland T (1865) Notes on certain terrestrial Mollusca, with descriptions of new species. Annals of the Lyceum of Natural History of New York 8: 155–170.
  • Burke TE (2013) Land snails and slugs of the Pacific Northwest. Oregon State University Press, Corvallis, Oregon, 344 pp.
  • Coan EV, Roth B (1987) The malacological taxa of Henry Hemphill. The Veliger 29: 322–339.
  • Eyerdam WJ (1933) A biological collecting excursion to the Aleutian Islands. The Nautilus 46: 124–128.
  • Gittenberger E, Budha PB, Bank RA (2020) Amazing Paralaoma servilis (Gastropoda, Pulmonata, Punctidae) in Nepal. Basteria 84: 76–82.
  • Lowe RT (1831) Primitæ faunæ et floræ Maderæ et Portus Sancti; sive species quædam novæ vel hactenus minus vite cognitæ animalium et plantarum in his insulis degentium breviter descritæ. Transactions of the Cambridge Philosophical Society 4: 1–70, pls 1–6.
  • Pilsbry HA (1896) A new variety of Punctum. The Nautilus 10: 21–22.
  • Pilsbry HA (1948) Land Mollusca of North America (north of Mexico). Vol. II, Part 2. The Academy of Natural Sciences of Philadelphia, Monographs 3: i–xlvii + 521–1113.
  • Pilsbry HA, Ferriss JH (1919) Mollusca of the southwestern states—IX, the Santa Catalina, Rincon, Tortillita and Galiuro mountains. X, the mountains of the Gila headwaters. Proceedings of the Academy of Natural Sciences of Philadelphia 70: 282–333, pls 283–287.
  • Reeve LA (1851–1854) Monograph of the genus Helix. Conchologica Iconica; Or, Illustrations of the Shells of Molluscous Animals 7: pl. 1–6 [March 1851]; pl. 7–14 [April 1851]; pl. 15–22 [May 1851]; pl. 23–30 [June 1851]; pl. 31–38 [July 1851]; pl. 39–46 [September 1851]; pl. 47–54 [October 1851]; pl. 55–62 [December 1851]; pl. 63–70 [January 1852]; pl. 71–78 [February 1852]; pl. 79–86 [March 1852]; pl. 87–84 [April 1852]; pl. 95–102 [May 1852]; pl. 103–110 [June 1852]; pl. 111–126 [August 1852]; pl. 127–132 [October 1852]; pl. 133 [“October 1851”; probably October 1852]; pl. 134: [October 1852]; pl. 135–142 [November 1852]; pl. 143–146 [December 1852]; pl. 147–150 [February 1853]; pl. 151–154 [April 1853]; pl. 155–162 [May 1853]; pl. 163–166 [June 1853]; pl. 167–170 [July 1853]; pl. 171–174 [October 1853]; pl. 175–176 [April 1854]; pl. 177 [May 1854]; pl. 178–185 [June 1854]; pl. 186–189 [July 1854]; pl. 190–193 [August 1854]; pl. 194–195 [September 1854]; pl. 196–210 [December 1854]; title p., index, errata. [Dates stated on explanatory pages accompanying plates, except for pl. 133, which appears to be misdated (Petit 2007).]
  • Roth B (1985) A new species of Punctum (Gastropoda: Pulmonata: Punctidae) from the Klamath Mountains, California, and first Californian records of Planogyra clappi (Valloniidae). Malacological Review 18: 51–56.
  • Roth B (1986) Notes on three European land mollusks introduced to California. Bulletin of the Southern California Academy of Sciences 85: 22–28.
  • Roth B (1987) “Punctum pusillum” (Gastropoda: Pulmonata: Punctidae)—a correction. The Veliger 30: 95–96.
  • 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.
  • Shuttleworth RJ (1852) Diagnosen neuer Mollusken. Haller’schen Buchdruckerei, Bern, 163 pp.
  • Smith AG, Miller WB, Christensen CC, Roth B (1990) Land Mollusca of Baja California, Mexico. Proceedings of the California Academy of Sciences 47: 95–158.