Fessisentis tichiganensis sp. nov. (Acanthocephala: Fessisentidae) from Wisconsin fishes, with a key to species.

Fessisentis tichiganensis sp. nov. is described on the basis of 16 male and 24 female worms recovered from 11 species of fish of seven families in Tichigan Lake, southeastern Wisconsin, between 1977 and 1979. Specimens were most frequently encountered during the spring; the only two gravid females were recovered from Umbra limi, in early June. The same fish also serves as a transport host. A key separating F. tichiganensis from the four other known species in North America is presented. The new species most closely resembles F. friedi Nickol 1972 (= F. vancleavei haley and Bullock 1953), but can be separated from it by its longer proboscis which is armed with markedly more hooks per row, among other characteristics. Additional, new morphological observations are also reported.