Erimyzon

Abstract: . Starch gel electrophoresis was utilized to investigate biochemical aspects of ontogeny in two distantly related teleost fishes, the lake chubsucker (Erimyzon sucetta) and the green sunfish (Lepomis cyanellus). Isozyme patterns of embryonic stages and of various adult tissues were determined for over 15 different enzymes (representing more than 30 genetic loci).

Abstract: Eggs, larvae, and early juveniles of Catostomus commersoni, Hypentelium nigricans, Moxostoma macrolepidotum, Carpiodes cyprinus, and Erimyzon oblongus are described. Taxonomic keys are provided. Comparisons of developmental traits reveal two groups of larvae based on size at a given developmental stage. The larger species, the first three above, are very similar to one another. The other two are not difficult to distinguish. The large size of the posterior gas bladder chamber in C. commersoni is unique. Hypentelium nigricans has distinctive pigmentation in the dorsal and caudal fins. Moxostoma macrolepidotum is typically deeper bodied than the others. Catostomus commersoni is the most filiform of the large species. Erimyzon oblongus has a median pigment-free space on the dorsum which is not present in the other species. Combinations of morphometric parameters are used as key characteristics. Construction of these characters takes into account the high degree of allometric growth observed in these...

Abstract: Monozoic cestodes of the recently amended genus Promonobothrium Mackiewicz, 1968 (Cestoda: Caryophyllidea), parasites of suckers (Cypriniformes: Catostomidae) in North America, are reviewed, with information on their host specificity, distribution and data on the scolex morphology of seven species studied for the first time using scanning electron microscopy (SEM). Evaluation of type and voucher specimens from museum collections and newly collected material of most species indicated the following valid nominal species: Promonobothrium minytremi Mackiewicz, 1968 (type species); P. ingens (Hunter, 1927); P. hunteri (Mackiewicz, 1963); P. ulmeri (Calentine et Mackiewicz, 1966); P. fossae (Williams, 1974) and P. mackiewiczi (Williams, 1974). Rogersus Williams, 1980 with its only species R. rogersi is transferred to Promonobothrium based on morphological and molecular data. Promonobothrium currani sp. n. and P. papiliovarium sp. n. are described from Ictiobus bubalus (Rafinesque) and Ictiobus niger (Rafinesque), and Erimyzon oblongus (Mitchill), respectively. The newly described species can be distinguished from the other congeners by the morphology of the scolex, the position of the anteriormost vitelline follicles and testes, the presence of postovarian vitelline follicles and the shape of the ovary. Molecular phylogenetic analyses of six species based on sequences of the small and large subunits of the nuclear ribosomal RNA genes (ssrDNA, lsrDNA) confirmed the monophyletic status of the genus and supported the validity of the species analysed. A key to identification of all species of Promonobothrium based on morphological characteristics is provided.

Abstract: One hundred sixty-three fish from four natural ponds in Florida were examined for parasites. Of these, 40 were grass carp (Ctenopharyngodon idella), an exotic herbivorous fish which had been introduced for research as a possible biological control of aquatic vegetation. The remaining 123 fish included six native species (largemouth bass, Micropterus salmoides; bluegill, Lepomis macrochirus; golden shiner, Notemigonus crysoleucas; lake chubsucker, Erimyzon sucetta; brown bullhead, Ictalurus nebulosus; yellow bullhead, Ictalurus natalis). Parasite faunas of the native fishes and grass carp were compared. Identified were 37 species of parasites from the native fishes and one species from grass carp. No exotic parasites were observed in the grass carp, but the grass carp were infected by a native parasite of the phylum Pentastomida, Sebekia oxycephala.