A new milliped of the genus Metaxycheir from the Pacific coast of Canada (Polydesmida: Xystodesmidae), with remarks on the tribe Chonaphini and the western Canadian and Alaskan diplopod fauna

Abstract

Metaxycheir pacifica, a new chonaphine xystodesmid milliped from Vancouver Island, British Columbia, inhabits decidous spots in the forests along the Pacific Ocean from Bamfield to China Beach Provincial Park. It displays a subcylindrical body, imparted by reduced paranota caudal to segment 4; an acropodite in the form of a broad, open loop; and an acicular prefemoral process with minute subapical barbules. It is segregated from the type species, M. prolata Buckett and Gardner, in northern Idaho, by over 600 km, and is the second western Canadian xystodesmid. The tribe Chonaphini occupies five areas of allopatric populations: that of M. pacifica; from central Oregon to western Montana; and three areas in the north central and eastern states. The Pacific coastal region harbors the most diverse fauna of western Canada, and a second center of diversity lies around Mount Revelstoke and Glacier national parks. The diplopod fauna of Alaska and western Canada consists of at least 5 orders, 13 families, 22 genera, and 24 species; of these, 5, 10, 16, and 17 are indigenous forms and 2, 4, 6, and 7 are introductions, respectively. The chordeumatoid family Rhiscosomididae and the genus Rhiscosomides are new to Canada; five allochthonus species, Cylindroiulus caeruleocinctus (Wood), Ophyiulus pilosus (Newport), Oxidus gracilis (C. L. Koch), Brachydesmus superus Latzel, and Polydesmus inconstans Latzel, are new to the western provinces; and the Polyxenidae (Polyxenida) and Caseyidae (Chordeumatida) are new to Alaska.

Influence of millipedes on litter decomposition, N mineralization, and microbial communities in a coastal forest in British Columbia, Canada

“…In addition to H. haydeniana, other invertebrates including earthworms, molluscs, isopods, arthropods, and other millipedes are expected to feed on litter. For example, in Vancouver Island, another large xystodesmid millipede (Tubaphe levii Causey) was found on mesic sites (Shelley 1990(Shelley , 1993 and likely plays a similar role in litter breakdown. We conclude, therefore, that at least 36% of the litter produced in coastal forests of British Columbia is probably consumed and thus transformed by soil macrofauna.…”

Diversity of Soil Arthropods in Canada: Systematic and Ecological Problems

“…Detailed knowledge of life histories and population dynamics of the species of these large myriapod classes that occur in Canada is lacking, despite the availability of excellent syntheses documenting known distributions of recorded species (Kevan 1983a(Kevan , 1983bShelley 1988Shelley , 1990). In addition, a recent illustrated key to the families of Myriapoda provides an easily comprehended introduction to the classes (Kevan and Scudder 1989).…”

Diplopoda, Chordeumatida, Caseyidae, Opiona columbiana Chamberlin, 1951: distribution extensions into the Alexander Archipelago, Alaska, USA, Queen Charlotte Islands, British Columbia, Canada, and eastern & southern Washington State, USA; additional new records from British Columbia and Washington

“…Three localities are known -Victoria, the type locality, and Vancouver, British Columbia, and Seattle, King County (Co.), Washington, the type locality of the synonym, O. hatchi Causey, 1954;additionally, Shelley (1990) Chamberlin, 1925(Shelley 1993, but the species is O. columbiana, as the gonopods agree closely with the illustrations by Gardner and Shelley (1989:213, figures 85-87). The record thus constitutes an astounding range extension of around 1,008 km (630 mi) for both the genus and species, and suggests that the female caseyid from Juneau reported by Shelley (1990) and later assigned to U. tida (Shelley 1993, Hoffman 1999 may also be O. columbiana; RMS confirmed familial occurrence in Juneau on August 18 by collecting an early instar caseyid at the entrance to Perseverance Trail. The aforementioned localities lie along a narrow, east-west axis, but we can report significant expansion in this dimension as well.…”

“…The milliped, Opiona columbiana Chamberlin, 1951 (Chordeumatida: Caseyidae), the northernmost representative of the genus and the northernmost in the family aside from the species of Underwoodia Cook & Collins, 1895, is known from the Puget Sound region of Washington State, USA, and the southwestern corner of British Columbia, Canada, on both the mainland and Vancouver Island (Chamberlin 1951;Causey 1954;Chamberlin and Hoffman 1958;Kevan 1983;Gardner and Shelley 1989;Shelley 1990Shelley , 1993Shelley , 2002Hoffman 1999). Three localities are known -Victoria, the type locality, and Vancouver, British Columbia, and Seattle, King County (Co.), Washington, the type locality of the synonym, O. hatchi Causey, 1954;additionally, Shelley (1990) Chamberlin, 1925(Shelley 1993, but the species is O. columbiana, as the gonopods agree closely with the illustrations by Gardner and Shelley (1989:213, figures 85-87).…”

“…This situation exemplifies the difficulty in sampling diplopods in Alaskan rainforests, for aside from the ubiquitous representatives of the Parajulidae (order Julida) and the diverse faunas on the southernmost islands (Revillagigedo, Annette, Prince of Wales, and Dall, etc. (Shelley 1990)), millipeds are scattered and can be virtually anywhere; consequently, encounters are primarily chance events. The new samples from Washington were discovered in "Oregon White Oak (Quercus garryana) leaf litter," "on soil under a rock," and in a "compost pile and garden," all typical milliped habitats.…”