Possible Recent Range Expansion of \u3ci\u3eAlcataenia longicervica\u3c/i\u3e (Eucestoda: Dilepididae) Parasitic in \u3ci\u3eMurres uria\u3c/i\u3e spp. (Alcidae) into the North Atlantic [Short Communications]

A wide range of helminths has been recorded from murres Uria spp. (Threlfall 1971, reviewed by Hoberg 1984a, Muzaffar & Jones 2004). Of the cyclophyllidean cestodes that parasitize murres, the genus Alcataenia Spasskaya 1971 (Dilepididae) is represented by ten species, eight of which are restricted and specific to the auks; the other two species occur in gulls (Laridae). The intermediate hosts of Alcataenia are euphausiid crustaceans such as species of Thysanoessa (Shimazu 1975), which also form an important dietary component of breeding and wintering murres, particularly Thick-billed Murres Uria lomvia (Gaston & Noble 1985, Birkhead & Nettleship 1987, Elliot et al. 1990, Rowe et al. 2000, Ainley et al. 2002). Alcataenia armillaris Rudolphi 1810 and A. meinertzhageni Baer 1956 are restricted to the murres and have been recorded from different locations in the Holarctic (Threlfall 1971; Hoberg 1984a, 1986). Alcataenia longicervica Hoberg 1984 was described from murres in the North Pacific basin and has been regarded as endemic to the region (Hoberg 1986) because relatively extensive surveys of murres from the North Atlantic and Arctic basin have previously failed to find the species (e.g. Markov 1937, 1942, Belopolskaya 1952, Threlfall 1971, Galkin et al. 1994). We report a new geographic record of A. longicervica in wintering Thick-billed Murres and Common Murres Uria aalge. Thick-billed Murres and Common Murres were collected by hunters in February 2005 from Harbor Breton (47.467°N, 55.800°W) and St. Mary’s Bay (46.933°N, 53.583°W), Newfoundland. Each bird was dissected, and the gastrointestinal tracts were frozen. These samples were later analyzed under a dissecting microscope to collect helminths. Helminth specimens were preserved in 70% ethanol and subsequently stained in Semichon acid carmine stain and mounted entire for identification. The armed rostellum was dissected from some specimens and mounted separately to facilitate accurate determination of form, number, distribution and dimensions of hooks. Identifications were based on descriptions or re-descriptions (Hoberg 1984b) and direct comparison to holotype, paratype or known voucher specimens representing species of Alcataenia held in the U.S. National Parasite Collection (USNPC), Beltsville, Maryland, U.S.A