17 research outputs found
Age, Growth, and Gonadal Characteristics of Adult Bighead Carp, Hypophthalmichthys nobilis, in the Lower Missouri River
Habitat use and population structure of four native minnows (family Cyprinidae) in the upper Missouri and lower Yellowstone rivers, North Dakota (USA)
Differential responses of body shape to local and reach scale stream flow in two freshwater fish species
Modelling effects of disturbance on population dynamics of generalized crayfish life history strategies
Demographics of the spawning aggregations of four catostomid species in the Savannah River, South Carolina and Georgia, USA
Factors influencing recruitment of walleye and white bass to three distinct early ontogenetic stages
Hybridization and Reproductive Isolation among Syntopic Populations of the Topminnows Fundulus Notatus and F. Olivaceus
Fundulus notatus and Fundulus olivaceus are two closely related topminnow species that exhibit similar ecological niches and broad, largely overlapping, North American ranges extending throughout much of the Mississippi River drainage as well as the coastal drainages of the Gulf of Mexico. Previous studies have suggested that these two species are reproductively compatible despite cytogenetic differences and will hybridize when syntopic. We used nuclear and mtDNA loci to assess levels of hybridization and test for introgression in syntopic populations of these two species in four drainages in southern Illinois. Although hybridization was detected in all syntopic populations, an assessment of the proportion of hybrid individuals indicated a deficiency of hybrids relative to expectations under random mating. We determined that, although mtDNA introgression was prevalent and extended beyond the zones of contact, evidence of nuclear introgression was limited to the zone of sympatry