Section of Mollusks

Pittsburgh, PA, United States

Section of Mollusks

Pittsburgh, PA, United States
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Hotopp K.P.,Appalachian Conservation Biology | Pearce T.A.,Section of Mollusks | Nekola J.C.,University of New Mexico | Schmidt K.,Hudsonia Ltd.
Proceedings of the Academy of Natural Sciences of Philadelphia | Year: 2010

Recent land snail inventories in New York State have led to the discovery of new state geographic distribution records for seven species: Carychium nannodes Clapp, 1905; Gastrocopta procera (Gould, 1840); Lucilla scintilla (R.T. Lowe, 1852); Striatura meridionalis (Pilsbry and Ferriss, 1906); Trochulus hispida (Linnaeus, 1758); Vertigo cristata Sterki, 1919; and Vertigo paradoxa Sterki, 1900. Most are native species of eastern North America, although T. hispida is introduced from Europe. These species were found mainly by field searches in a variety of habitats roadsides, fields, forested rock talus and limestone outcrops, and coastal freshwater wetlands - but in one case through verification of specimens at the New York State Museum.

Pearce T.A.,Section of Mollusks | Olori J.C.,University of Texas at Austin | Kemezis K.W.,Apt. 608
Annals of Carnegie Museum | Year: 2010

The presence of the European land snail, Cepaea hortensis (Mller, 1774), in archaeological deposits indicates its existence in North America before the arrival of post-Columbus European settlers. We address whether this species arrived in North America before Viking explorers. Evidence from cave deposits in St. Elzear de Bonaventura Cave on the Gaspé Peninsula, Quebec, suggests that C. hortensis appeared in North America prior to arrival of the Vikings about 1000 YBP and possibly more than 7850 YBP. The presence of the larger snail species Anguispira alternata (Say, 1816) and Neohelix albolabris (Say, 1817) in cave levels representing tundra to taiga conditions, coupled with their absence as far north as modern taiga, suggests that some large snails may not disperse quickly enough to occupy all favorable habitat made available by warming climates.

Orstan A.,Section of Mollusks | Cameron R.A.D.,University of Sheffield | Cameron R.A.D.,Natural History Museum in London
Journal of Conchology | Year: 2015

The European land snail Cepaea nemoralis was introduced into Burlington, New Jersey, USA by William G. Binney in 1857 with specimens from near Sheffield, England. First in 1869 and later in 1878, Binney noted that the species had become widespread throughout the city. Between 1908 and 1933, Henry A. Pilsbry collected a large number of C. nemoralis shells in Burlington and noted that the species was still abundant in the early 1930s. A survey done in Burlington in 2013 and 2014 that included some of Pilsbry's localities found only six live snails and six empty shells. The only live snails were found near where Binney's house was in the nineteenth century. Our results show that both the range and the population of C. nemoralis in the city have declined drastically since the 1930s. The Burlington colony of C. nemoralis is characterized by high frequencies of unhanded or one-banded morphs. This suggests that Binney's founding lot may have originated from the White Peak district of Derbyshire near Sheffield, England.

The obsolescence of radial sculpture on the last whorl of the land snail Ancotrema hybridum (Ancey, 1888) has been used to separate it from A. sportella (Gould, 1846), but shells are sometimes difficult to assign to one species or the other, prompting questions about their species status. Factor analysis of shell characters of 311 specimens of Ancotrema Baker, 1931, including characters of surface sculpture strength, shell size and rib density, revealed continuous variation of these characters without bimodality. Radial sculpture begins obsolescing at about whorl five, so shells that stopped growing near whorl five have A. sportella-like morphology, while those that continued growing after whorl five have A. hybridum-like morphology. We saw no meaningful differences in the genital anatomy that would suggest different species. The obsolescence of sculpture beginning about whorl five regardless of ultimate whorl number, lack of bimodality of shell characters, and lack of anatomical differences lead us to conclude that the two forms are a single species. Ancotrema hybridum is a junior synonym of A. sportella.

Orstan A.,Section of Mollusks
Quaternary International | Year: 2015

A survey was carried out to determine the distribution range of Cochlostoma mienisi Schütt, 1978, a little studied land snail of southwestern Turkey. The species was found on the island of Kekova off the coast of Turkey and at an additional location on the mainland facing the island. The closest congeners of C. mienisi are on Crete and mainland Greece, more than 400 km away. As a possible explanation for its limited and disjunct range, it is proposed here that C. mienisi may have been introduced from another location by the shipping trade in the antiquity. No live snails were seen, but various conchological traits of C. mienisi provided clues to its biology and ecology. The presence of two overlapping size groups in the distribution of adult shell dimensions is interpreted as an indication of a sexual dimorphism: the larger shells (8.0 mm × 3.5 mm) are those of female snails and the smaller ones (7.4 mm × 3.3 mm) are of males. Also discussed are the structure of the operculum of C. mienisi, decollation observed in a few shells and the presence of small circular holes that were probably bored by an unknown predator or a parasite. © 2015 Elsevier Ltd.

Pearce T.A.,Section of Mollusks | Paustian M.E.,Section of Mollusks
American Malacological Bulletin | Year: 2013

Distributions of some plants and animals have already shifted in recent years due to climate warming, and climate warming has potential to extirpate populations of taxa that cannot easily move or adapt to changes in temperatures and/or moisture. This study in Pennsylvania, U.S.A. focuses on whether snail populations currently confined to cooler habitats at higher elevations (elevations 700-978 m comprise only 2% of Pennsylvania's area) might decline or be eliminated if their ranges are reduced upward by climate warming. We examined whether some land snail species are limited to upper elevations in order to assess whether climate warming poses a threat to them. Sampling included 108 sites across Pennsylvania, comprising 12 localities at each of nine elevations from 100 to 900 m elev. Overall numbers of snail species and abundances decreased at greater elevations. Most individual species tended to occur throughout sampled elevations or occurred primarily at lower elevations, so the reduced altitudinal range aspect of climate warming might not threaten them. However, five species occurred significantly more often at greater elevations suggesting that their populations might decline if climate warming were to reduce their ranges upward. Four additional species including three native slugs showed non-significant trends to occur at higher elevations. These species might be monitored into the future.

Orstan A.,Section of Mollusks
American Malacological Bulletin | Year: 2010

I studied the reproduction and the population turnover of a succineid land snail living by a small lake in central Maryland. The identity of the snail, deduced from its external characteristics and the genitalia, comes closest to Oxyloma retusum (Lea, 1834). The species has a semelparous life cycle. The snails that survive the winter grow and reproduce from late March until the end of June when they reach their maximum size and die off. Their offspring (the spring generation) grow throughout the spring and the summer and reproduce briefly near the end of August. In the fall, the survivors from the spring generation and their offspring hibernate from November until the end of March. Snails mate by shell-mounting. In 89% of pairs, mating was anatomically reciprocal. During courtship, one snail climbs on the shell of a prospective mate and circles the shell to initiate mating. In mating pairs with a shell length difference of more than 1 mm, the smaller snail was always on top. This suggests that one function of shell-circling during courtship may be to help the top snail judge its potential partner's size.

Comparison of the shells of a land snail collected in Montreal, Canada with those of several North American and European Discus species resulted in the identification of the Montreal specimens as the European Discus rotundatus. © 2012 Check List and Authors.

A new genus and species, Patriciapecten iona, are described in the subfamily Chlamydinae (Mollusca: Bivalvia: Pectinidae). Patriciapecten is characterized by a shell with commarginal ledges giving an undulating surface, strong radial ribs, and no intermediate hinge teeth. The type locality is the Lee Creek Mine operated by the Potash Corporation of Saskatchewan (formerly Texasgulf, Inc.) near Aurora, Beaufort County, North Carolina, where the specimen was collected in a spoil pile. This site, which is primarily upper Cenozoic, ranges from the Miocene Period through the Holocene Epoch.

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