The Land Snail Cryptomastix germana (Gastropoda ... · The coastal land snail Cryptomastix germana,...
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316 THE CANADIAN FIELD-NATURALIST Vol. 114 The Land Snail Cryptomastix germana (Gastropoda: Polygyridae) in the Queen Charlotte Islands, British Columbia: A Range Extension North from Vancouver Island ROBERT G. FORSYTH 2574 Graham Street, Victoria, British Columbia V8T 3Y7, Canada Forsyth. Robert G. 2000. The land snail Cryptomastix germana (Gastropoda: Polygyridae) in the Queen Charlotte Islands, British Columbia: a range extension north from Vancouver Island. Canadian Field-Naturalist 114(2): 316-317. The coastal land snail Cryptomastix germana, not previously known to occur north of Vancouver Island, is reported from the Queen Charlotte Islands, British Columbia. Key Words: Cryptomastix germana, Polygyridae, terrestrial gastropods, range extension, Queen Charlotte Islands, British Columbia Cryptomastix germana (Gould in W. G. Binney, 1851), the Pygmy Oregonian, is a small polygyrid land snail inhabiting the coastal regions and lowland valleys from Coos Bay, Oregon, to British Columbia (Pilsbry 1940; Vagvolgyi 1966) which has been vari- ously treated taxonomically. Pilsbry (1940) made distinctions between northern and southern popula- tions of Triodopsis (Cryptomastix) germana (Webb [ 1954] later elevated Cryptomastix to full generic rank) and applied the subspecific name T. germana vancouverinsulae (Pilsbry and Cooke, 1922) for populations north of the Columbia River. The pre- sumed differences between T. germana vancouverin- sulae and the nominal subspecies were said to inter- grade (Vagvolgyi 1966; Branson 1977), contrary to the opinion of Pilsbry (1940), and Vagvolgyi treated T. germana vancouverinsulae as a synonym. C. ger- mana is the type and presently only known species in the genus-level taxon Micranepsia Pilsbry, 1940 (described as a "section" of Cryptomastix and recently raised subgeneric status [Emberton 1995]). Some dissections of British Columbia and Washington material done in the 1970s have within them variation in the genitalia that has not been thor- oughly investigated (F. W. Grimm, personal commu- nication). On the southwest coast of British Columbia, C. germana is a widespread species of moderate abun- dance in deciduous or mixed deciduous-coniferous woods where it lives under logs and in leaf litter. During wet weather this snail has also been collected high off the ground on fronds of the Sword Fern (Polystichum munitum). Cameron (1986) found that C. germana showed a strong association with damp conditions. On the mainland of British Columbia, Crypto- mastix germana has previously been reported from the valley of the Chilliwack River (Whiteaves 1902; Cameron 1986), Popkum (Cameron 1986), University of British Columbia Endowment Lands (Cameron 1986), and Stanley Park, Vancouver (Pi1sbry 1940). On Vancouver Island, there are pub- lished records from Bamfield, Menzies Bay, Elk Falls, Home Lake (all Cameron 1986), Cameron Lake (Pilsbry and Cooke 1922; Pilsbry 1940; Cameron 1986), Sproat Lake (Cameron 1986), Cowichan River (Hanham 1914 ), Goldstream Provincial Park (Branson 1980), south of Union (Pilsbry 1940), and near Victoria (Pilsbry 1940). The most northern of these localities is Menzies Bay on Vancouver Island (circa 50°07'N, l25°23'W). Cryptomastix germana is here reported from the Queen Charlotte Islands for the first time. Its pres- ence there is based on a specimen collected on 8 May 1995 at Moresby Camp on Moresby Island (circa 53°03'N, 132°02'W). This record represents a significant range extension north from the previous northernmost locality on Vancouver Island, a dis- tance of approximately 560 km (on a bearing of 287°). It was collected with Vespericola columbi- anus (I. Lea, 1838), Northwest Hesperian; Haplo- trema vancouverense (I. Lea, 1839), Robust Lance- tooth; and Ancotrema sportella (Gou1d, 1846), Beaded Lancetooth, from under a fallen log in a wooded area around Moresby Camp. This locality, an abandoned logging camp now used as a forest service camp site and landing, has been extensively disturbed by human activities and is dominated by deciduous trees and young conifers. Red Alder (Alnus rubra) is abundant. The possibility that C. germana is introduced into the Mores by Camp appears very unlikely, since C. germana was sympatric with other native coastal land snails, none of which show a propensity to be introduced. The presence of these species at Mores by Camp suggests that they are capable of sur- viving in or recolonising sites substantially modified by logging activities. The specimen, which is fully adult with a well- developed apertural denticle and flared outer lip, measures 4.4 mm in height by 6.8 mm in width (exclusive of the lip). There are approximately 4¾ whorls, counted by the method of Kerney and Cameron (1979). The periostracal hairs are largely
Transcript of The Land Snail Cryptomastix germana (Gastropoda ... · The coastal land snail Cryptomastix germana,...
316 THE CANADIAN FIELD-NATURALIST Vol. 114
The Land Snail Cryptomastix germana (Gastropoda: Polygyridae) in the Queen Charlotte Islands, British Columbia: A Range Extension North from Vancouver Island
ROBERT G. FORSYTH
2574 Graham Street, Victoria, British Columbia V8T 3Y7, Canada
Forsyth. Robert G. 2000. The land snail Cryptomastix germana (Gastropoda: Polygyridae) in the Queen Charlotte Islands, British Columbia: a range extension north from Vancouver Island. Canadian Field-Naturalist 114(2): 316-317.
The coastal land snail Cryptomastix germana, not previously known to occur north of Vancouver Island, is reported from the Queen Charlotte Islands, British Columbia.
Key Words: Cryptomastix germana, Polygyridae, terrestrial gastropods, range extension, Queen Charlotte Islands, British Columbia
Cryptomastix germana (Gould in W. G. Binney, 1851), the Pygmy Oregonian, is a small polygyrid land snail inhabiting the coastal regions and lowland valleys from Coos Bay, Oregon, to British Columbia (Pilsbry 1940; Vagvolgyi 1966) which has been vari-ously treated taxonomically. Pilsbry (1940) made distinctions between northern and southern popula-tions of Triodopsis (Cryptomastix) germana (Webb [ 1954] later elevated Cryptomastix to full generic rank) and applied the subspecific name T. germana vancouverinsulae (Pilsbry and Cooke, 1922) for populations north of the Columbia River. The pre-sumed differences between T. germana vancouverin-sulae and the nominal subspecies were said to inter-grade (Vagvolgyi 1966; Branson 1977), contrary to the opinion of Pilsbry (1940), and Vagvolgyi treated T. germana vancouverinsulae as a synonym. C. ger-mana is the type and presently only known species in the genus-level taxon Micranepsia Pilsbry, 1940 (described as a "section" of Cryptomastix and recently raised subgeneric status [Emberton 1995]). Some dissections of British Columbia and Washington material done in the 1970s have within them variation in the genitalia that has not been thor-oughly investigated (F. W. Grimm, personal commu-nication).
On the southwest coast of British Columbia, C. germana is a widespread species of moderate abun-dance in deciduous or mixed deciduous-coniferous woods where it lives under logs and in leaf litter. During wet weather this snail has also been collected high off the ground on fronds of the Sword Fern (Polystichum munitum). Cameron (1986) found that C. germana showed a strong association with damp conditions.
On the mainland of British Columbia, Crypto-mastix germana has previously been reported from the valley of the Chilliwack River (Whiteaves 1902; Cameron 1986), Popkum (Cameron 1986), University of British Columbia Endowment Lands (Cameron 1986), and Stanley Park, Vancouver (Pi1sbry 1940). On Vancouver Island, there are pub-
lished records from Bamfield, Menzies Bay, Elk Falls, Home Lake (all Cameron 1986), Cameron Lake (Pilsbry and Cooke 1922; Pilsbry 1940; Cameron 1986), Sproat Lake (Cameron 1986), Cowichan River (Hanham 1914 ), Goldstream Provincial Park (Branson 1980), south of Union (Pilsbry 1940), and near Victoria (Pilsbry 1940). The most northern of these localities is Menzies Bay on Vancouver Island (circa 50°07'N, l25°23'W).
Cryptomastix germana is here reported from the Queen Charlotte Islands for the first time. Its pres-ence there is based on a specimen collected on 8 May 1995 at Moresby Camp on Moresby Island (circa 53°03'N, 132°02'W). This record represents a significant range extension north from the previous northernmost locality on Vancouver Island, a dis-tance of approximately 560 km (on a bearing of 287°). It was collected with Vespericola columbi-anus (I. Lea, 1838), Northwest Hesperian; Haplo-trema vancouverense (I. Lea, 1839), Robust Lance-tooth; and Ancotrema sportella (Gou1d, 1846), Beaded Lancetooth, from under a fallen log in a wooded area around Moresby Camp. This locality, an abandoned logging camp now used as a forest service camp site and landing, has been extensively disturbed by human activities and is dominated by deciduous trees and young conifers. Red Alder (Alnus rubra) is abundant.
The possibility that C. germana is introduced into the Mores by Camp appears very unlikely, since C. germana was sympatric with other native coastal land snails, none of which show a propensity to be introduced. The presence of these species at Mores by Camp suggests that they are capable of sur-viving in or recolonising sites substantially modified by logging activities.
The specimen, which is fully adult with a well-developed apertural denticle and flared outer lip, measures 4.4 mm in height by 6.8 mm in width (exclusive of the lip). There are approximately 4¾ whorls, counted by the method of Kerney and Cameron (1979). The periostracal hairs are largely
2000 NOTES 317
worn off, which has not been found to be the usual condition in other British Columbia material studied. The specimen is preserved as a dry shell only and is deposited in the Royal British Columbia Museum (Victoria) (999-00069-00 1).
The Queen Charlotte Island record is significant since it extends the known distribution of the species north from Vancouver Island, thus adding a consid-erable distance to the north-south range of this species. Moreover, the Queen Charlotte Island record suggests that Cryptomastix germana probably occurs elsewhere along the northern coast of British Columbia, a region of difficult access that requires further investigation.
Acknowledgments Tammy Forsyth helped collect the specimen
reported upon here . Wayne Grimrn (Clayton, Ontario) and an anonymous reviewer made valuable comments on the manuscript.
Literature Cited Branson, B. A. 1977. Freshwater and terrestrial Mollusca
of the Olympic Peninsula, Washington. Veliger 19: 310-330.
Branson, B. A. 1980. Collections of gastropods from the Cascade Mountain s of Washington. Veliger 23 : 171-176.
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Hanham, A. W. 1914. Notes on mollusks from British Columbia. Nautilus 28: 87-88.
Kerney, M. P., and R. A. D. Cameron. 1979. A field guide to the land snails of Britain and North-West Europe. Collins, London. 228 pages.
Pilsbry, H. A. 1940. Land Mollusca of North America (north of Mexico). The Academy of Natural Sciences of Philadephia, Monograph 3, 1(2): 575-994, i-ix.
Pilsbry, H. A., and C. M. Cooke. 1922. Land shells of Vancouver Island. Nautilus 36: 37-38.
Vagvolgyi, J. 1968. Systematics and evolution of the genus Triodopsis (Mollusca: Pulmonata: Polygryidae). Harvard University , Museum of Comparative Zoology, Bulletin 136: 145-254, 7 plates.
Webb, G. R. 1954. The life-history and sexual anatomy data on Ashmune/la with a revision of the triodopsin snails. Gastropodia 1: 13-18.
Whiteaves, J. F. 1902. Notes on some fresh-water and land shells from Keewatin, Northern Ontario and British Columbia. Ottawa Naturalist 16: 91-93.
Received 19 April 1999 Accepted 22 October 1999
