Descriptions of Larval Contracaecum variegatum (Rudolphi, 1809) and Adult Contracaecum sp. (Nematoda: Anisakidae) Collected from Seabirds of the Bering Sea.

Abstract

Third- and fourth-stage larvae of Contracaecum variegatum (Rudolphi, 1809) are described from specimens collected from the stomachs of the Thick-billed Murre (Uria lomvia), Common Murre (U. aalge), and Tufted Puffin (Lunda cirrhata) from the Bering Sea. The Tufted Puffin is a new definitive host for C. variegatum. Almost all of the seabirds examined were infected with a relatively high intensity with C. variegatum. It would therefore appear that this parasite is a very common and abundant nematode of seabirds in the Bering Sea. Contracaecum yamaguti (Mawson, 1956) is considered a junior synonym of C. variegatum. An adult of Contracaecum sp. with an aberrant ventricular appendix is described based on one fragment of a specimen from the stomach of the Common Murre.