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.

形态和属绦虫的分子评价Bothriocephalus Rudolphi，1808（绦虫纲：Bothriocephalidea），在加拿大和美国的淡水鱼基于新收集和固定均匀蠕虫透露意想不到的多样性。结合所选的形态学特征和4种分子标记（18S rDNA V8区，ITS1，ITS2和COI基因序列），鉴定了以下两种形态和谱系的伯氏头尾蛇Cooper，1917复合物，其中一些对其特异各自的鱼类最终寄主，并且可能代表不同的物种：来自角膜白斑的B. cuspidatus sensu stricto，Sander玻璃体（类型宿主），可能包括来自Johnny darter ，Etheostoma nigrum（均为Percidae）的微型形态。南瓜籽，Lepomis gibbosus（Centrarchidae）的Bothriocephalus形态型；和鲈鱼的头颅虫形态，Ambloplites rupestris（Centrarchidae）。金眼Hiodon alosoides（Hiodontidae）的Bothriocephalus形态型也可能代表一个单独的谱系（可能是Brioriocephalus texomensis Self，1954年），但需要进一步研究。小嘴鲈Micropterus dolomieu的形态型以单个标本为基础，在形态和遗传上都非常类似于岩鲈的形态型。对热灭活的和固定的标本的鳞茎和侧柏的形态学研究显示出一致的差异，通常是细微的，这使我们能够区分这些形态型。