Bolbophorus damnificus n. sp. (Digenea: Bolbophoridae) from the channel catfish Ictalurus punctatus and American white pelican Pelecanus erythrorhynchos in the USA based on life-cycle and molecular data

Abstract

The common pathogenic prodiplostomulum metacercaria in the flesh, mostly near the skin, of pond-produced channel catfish Ictalurus punctatus has been demonstrated to be Bolbophorus damnificus Overstreet & Curran n. sp. The catfish acquires the infection from the snail Planorbella trivolvis, the only known first intermediate host, and the species is perpetuated through the American white pelican Pelecanus erythrorhynchos, as confirmed by experimental infections with nestling and dewormed adult pelican specimens in conjunction with molecular data. It differs from the cryptic species Bolbophorus sp., also found concurrently in the American white pelican, by having eggs 123-129 microm rather than 100-112 microm long and consistent low values for nucleotide percentage sequence similarity comparing COI, ITS 1/2, 18S rRNA and 28S rRNA fragments. Bolbophorus sp. is comparable but most likely distinct from B. confusus (Kraus, 1914), which occurs in Europe and has eggs 90-102 microm long. Its intermediate hosts were not demonstrated. The adults of neither of the confirmed North American species of Bolbophorus were encountered in any bird other than a pelican, although several shore birds feed on infected catfish, and B. damnificus can survive but not mature when protected in the mouse abdominal cavity. B. ictaluri (Haderlie, 1953) Overstreet & Curran n. comb., a species different from B. damnificus, is considered a species inquirenda.