IN THE TUNDRA SWAN, CYGNUS COLUMBIANUS (ANATIDAE), FROM NORTH AMERICA

• Main Author: Sara V. Brant
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Cygnus columbianus; Tundra; Tundra Swan
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.517.5793; http://folia.paru.cas.cz/pdfs/fol/2007/02/04.pdf

Abstract. Twelve tundra swans, Cygnus columbianus (Ord), from Nevada and one from New Mexico were collected and examined for schistosomes. Mature worms, determined as Allobilharzia visceralis, were found in 92 % of the swans, in the inferior mesenteric vein of the large intestine and its branches. In 12 cases, there was endophlebitis of the inferior mesenteric vein. The morphology of the worms is consistent with the recently described genus Allobilharzia. Placement in this genus was confirmed also by phylogenetic analysis of nuclear 28S, 18S and, internal transcribed spacer (ITS) ribo-somal DNA (rDNA), and mitochondrial cytochrome oxidase I (CO1) sequences. Data further suggest the worms are con-specific with the European A. visceralis, the only described species of the genus and which was found to be the sister taxon to the most diverse avian schistosome genus, Trichobil-