Structure, biodiversity, and historical biogeography of nematode faunas inHolarctic ruminants: Morphological and molecular diagnoses for Teladorsagia boreoarcticus N-sp (Nematoda : Ostertagiinae), a dimorphic cryptic species in muskoxen (Ovibos moschatus)

Citation
Ep. Hoberg et al., Structure, biodiversity, and historical biogeography of nematode faunas inHolarctic ruminants: Morphological and molecular diagnoses for Teladorsagia boreoarcticus N-sp (Nematoda : Ostertagiinae), a dimorphic cryptic species in muskoxen (Ovibos moschatus), J PARASITOL, 85(5), 1999, pp. 910-934
Citations number
90
Categorie Soggetti
Biology,Microbiology
Journal title
JOURNAL OF PARASITOLOGY
ISSN journal
00223395 → ACNP
Volume
85
Issue
5
Year of publication
1999
Pages
910 - 934
Database
ISI
SICI code
0022-3395(199910)85:5<910:SBAHBO>2.0.ZU;2-U
Abstract
Discovery of the ostertagiine nematode Teladorsagia boreoarcticus n, sp, in muskoxen, Ovibos moschatus, from the central Canadian Arctic highlights th e paucity of knowledge about the genealogical and numerical diversity of ne matode faunas characteristic of artiodactyls at high latitudes across the H olarctic. Teladorsagin boreoarcticus is a dimorphic cryptic species disting uished from Teladorsagia circumcincta/Teladorsagia trifurcata in domestic s heep by a 13% divergence in the ND-I region of mitochondrial DNA constant d ifferences in the synlophe, and significantly longer esophageal valve, spic ules, gubernaculum, and bursa. Teladorsagin boreoarcticus represents an arc haic component of the North American fauna and may have a Holarctic distrib ution in muskoxen and caribou. Recognition of T. boreoarcticus in muskoxen, in part, corroborates hypotheses for the existence of a cryptic species co mplex of Teladorsagia spp. among Caprinae and Cervidae at high latitudes an d indicates the importance of climatological determinants during the late T ertiary and Pleistocene on diversification of the fauna. Also reinforced is the concept of the North American fauna as a mosaic of endemic and introdu ced species. Discovery of a previously unrecognized species of Teladorsagia has additional implications and clearly indicates that (I) our knowledge i s incomplete relative to potentially pathogenic nematodes that could be exc hanged among domestic and wild caprines; (2) we do not hale sufficient know ledge of the fauna to understand the ecological control mechanisms (limitat ions) on dissemination and host range, and (3) on understanding of historic al and geographical influences on the genealogical diversity and distributi on of nematode faunas in domestic and wild ruminants is requisite to define the interface between agricultural and natural ecosystems across the Holar ctic.