Morphological and molecular evaluation of tapeworms of the genus Bothriocephalus Rudolphi, 1808 (Cestoda: Bothriocephalidea), based on newly collected and uniformly fixed worms from freshwater fishes in Canada and the United States has revealed unexpected diversity. With a combination of selected morphological features and 4 molecular markers (18S rDNA V8 region, ITS1, ITS2, and COI gene sequences), the following morphotypes and lineages of the Bothriocephalus cuspidatus Cooper, 1917 complex were identified, several of which are specific to their respective fish definitive hosts and may represent separate species: B. cuspidatus sensu stricto from walleye, Sander vitreus (type host), which likely includes a miniature morphotype from Johnny darter, Etheostoma nigrum (both Percidae); Bothriocephalus morphotype from pumpkinseed, Lepomis gibbosus (Centrarchidae); and Bothriocephalus morphotype from rock bass, Ambloplites rupestris (Centrarchidae). The Bothriocephalus morphotype from goldeye, Hiodon alosoides (Hiodontidae), may also represent a separate lineage (possibly Bothriocephalus texomensisSelf, 1954) but requires additional studies. A morphotype from smallmouth bass, Micropterus dolomieu, based on a single specimen, is morphologically and genetically very similar to the morphotype from rock bass. Morphological study of the scolex and strobila of heat-killed and fixed specimens has revealed consistent differences, often subtle, that allowed us to differentiate between these morphotypes.

Division of Natural Sciences St Norbert College 100 Grant Street De Pere Wisconsin 54115

Institute of Parasitology Biology Centre of the Czech Academy of Sciences Branišovská 31 370 05 České Budějovice Czech Republic

References provided by Crossref.org

The diversity of Khawia tapeworms (Cestoda: Caryophyllidea) of barbels (Cyprinidae: Barbinae) in the western Palearctic: the existence of vicariant lineages and the description of a new species from the Iberian Peninsula

ERECTION OF BOTHRIOCESTUS N. GEN. (CESTODA: BOTHRIOCEPHALIDEA) AND REDESCRIPTION OF BOTHRIOCESTUS CUSPIDATUS (COOPER, 1917) (SYN. BOTHRIOCEPHALUS CUSPIDATUS) FROM WALLEYE, SANDER VITREUS, (PERCIFORMES: PERCIDAE) IN NORTH AMERICA

Fish tapeworms (Cestoda) in the molecular era: achievements, gaps and prospects

A young parasite in an old fish host: A new genus for proteocephalid tapeworms (Cestoda) of bowfin (Amia calva) (Holostei: Amiiformes), and a revised list of its cestodes

The role of the non-indigenous pumpkinseed Lepomis gibbosus (Actinopterygii: Centrarchidae) in the life cycle of Bothriocephalus claviceps (Cestoda: Bothriocephalidae) in Europe

Disentangling taxonomy of Biacetabulum (Cestoda, Caryophyllidea), parasites of catostomid fishes in North America: proposal of Megancestus gen. n. to accommodate B. carpiodi