The Crayfish of Nebraska

This print-ready pdf includes information on the anatomy, biology, and ecology of crayfishes of Nebraska, individual species accounts with maps, and a key to the species

The Nebraska Stream Fishery Surveys: Being a Comparison of the First Statewide Collections of Raymond Johnson (1939-1941) with a Recent Resurvey (2003-2005)

The first statewide survey of Nebraska fishes was done between 1939 and 1941. This survey was repeated between 2003 and 2005. This document compares and contrasts the results of those two surveys to illustrate what has changed and what hasn\u27t changed over that 60 year period. It is hoped that this document can serve as a resource for future researchers to track changes in Nebraska\u27s fish communities

Experimental analysis of reintroduction strategies to conserve the vulnerable plains topminnow Fundulus sciadicus in Nebraska

Plains topminnow Fundulus sciadicus are endemic to the Great Plains (USA), and because of declines in their geographic range and local abundance, are granted protection throughout their native range. Experimental reintroductions were conducted to improve conservation techniques and enhance the long-term outlook for plains topminnow persistence in Nebraska. Reintroductions were attempted at 17 extirpated stream reaches using low and high founder densities (no. of fish per suitable area) and during 2 seasons (spring and fall) to identify successful techniques for future conservation efforts. Reintroduced populations were sampled monthly (excluding winter) for 2 yr to monitor population persistence. Repeated presence-absence data was used to estimate persistence probabilities (1 - extinction probability), which we used to compare reintroduction strategy treatments. Plains topminnow were recaptured at 76% of reintroduction locations (1456 total individuals) and reproduction was observed at 35% of those sites. Catch rates at reintroduction sites varied substantially (range: 0 to 30.78 ind. per 100 m). The influence of season and founder density were minimal. Population persistence was more likely at sites stocked in fall at higher densities; however, wide confidence intervals suggest that individual site characteristics may more strongly influence population persistence. Similar population outcomes regardless of reintroduction strategy provide managers flexibility when making conservation decisions.Peer reviewedEntomology and Plant Patholog

The Ringed Crayfish, \u3ci\u3eOrconectes neglectus neglectus\u3c/i\u3e, in Nebraska with a Revision of Its Distributional Range

Collections of crayfishes in Nebraska have yielded much new information on the distribution of the ringed crayfish, Orconectes neglectus neglectus. The distributional range of this species had been described as southwestern Missouri and northwestern Arkansas with extensions into Kansas and Oklahoma. Isolated, disjunct populations in northeastern Colorado, southwestern Nebraska, and northwestern and east-central Kansas were thought to be relict populations. Between 1995 and 2009, collections of crayfishes were made throughout Nebraska using various techniques including seining, trapping, dip-netting, and handgrabbing. To date, the ringed crayfish has been found in 56 streams in eight of Nebraska’s 13 river basins. In the majority of Nebraska streams, they are found in clear, low-gradient, sand-bed streams where they utilize dense vegetative cover. In the Big Blue River basin, the streams are quite turbid and here they use rock riffles. The information collected during this work show that the previously known disjunct populations represent the edges of a much larger distribution centered in Nebraska. The data presented represents a significant revision of the range of distribution of this species

A Live Collection of a Pistolgrip from Nebraska

Freshwater mussels (Mollusca: Bivalvia: Unionidae) are one of Nebraska\u27s more poorly known faunas. Studies have documented the presence of 31 species of which only 19 have been found either live or freshly dead. The remaining twelve species have only been found as weathered or subfossil shells, seven of which were considered to be extirpated including the pistolgrip (Tritogonia verrucosa). While a statewide survey never has been done there is distributional information available in several published papers and unpublished reports (Baxa 1981; Hoke 1983, 1994a, 1995, 1996, 1997; Roedel 1990; Lingle 1992; Freeman and Perkins 1992, 1997; Clausen and Havlik 1994; Peyton and Maher 1995; Perkins and Backlund 2000) on the distributions of mussels in eight of Nebraska\u27s 13 river basins and a portion of the Missouri River. An additional publication (Hoke, 1994b) is a one page synopsis of collections in a ninth river basin. There is no published information for the Big Blue River, which is the subject of my note

A Guide to the Freshwater Mussels of Nebraska

This print-ready pdf includes information on the anatomy, life history, identification of and threats to Nebraska\u27s freshwater mussels. Species accounts include maps and photos

The Nebraska Stream Surveys--The Photographs: Nebraska Streams Photographed During Raymond Johnson\u27s Statewide Stream Fishery Survey (1939-41) and How They Look Now, 78 Years Later.

Raymond E. Johnson and associates surveyed Nebraska\u27s streams for fish (1939-1941). This print-ready pdf shows original photographs from the survey side-by-side with the author\u27s recent photographs from the same or nearby locations, along with comments regarding changes observed. Includes map and index of locations

The Nebraska Stream Fishery Surveys: Being a Comparison of the First Statewide Collections of Raymond Johnson (1939-1941) with a Recent Resurvey (2003-2005)

The first statewide survey of Nebraska fishes was done between 1939 and 1941. This survey was repeated between 2003 and 2005. This document compares and contrasts the results of those two surveys to illustrate what has changed and what hasn\u27t changed over that 60 year period. It is hoped that this document can serve as a resource for future researchers to track changes in Nebraska\u27s fish communities

River geomorphology and fish barriers affect on spatial and temporal patterns of fish assemblages in the Niobrara River, Nebraska

The Niobrara River in northern Nebraska traverses the heart of the Great Plains with portions of the river protected under the National Wild and Scenic River system managed by the National Park Service. The Niobrara River changes from a narrow, entrenched stream to a wide, highly braided river with four fish barriers and 36 distinct geomorphic segments in the lower 531 river kilometers (rkm). Our objectives were to examine the spatial and temporal patterns of fish assemblages in the Niobrara River related to environmental variables, fish barriers, and river geomorphology. Tote-barge electrofishing occurred monthly from June to September in 2009 at 17 sites downstream of Dunlap Diversion Dam near Hemingford, Nebraska (river kilometer [rkm] 531) to the mouth (rkm 0) where the Niobrara River meets the Missouri River. In all, we collected 33,888 fish from 42 species and 11 families. Species richness was greatest near the mouth (rkm 4) and subsequently declined sharply upstream of the first fish barrier (Spencer Dam; rkm 63). Monthly changes in the fish assemblages were generally low with most differences due to young of the year, large-bodied fish recruiting to the electrofishing gear. Fish barriers, both anthropomorphic and natural, had significant impacts on the fish community by blocking fish migration, creating high abundances downstream of the structures, and species absent above the barriers. Bray-Curtis dissimilarity values between sample sites ranged from 45.4 to 96.5, which indicated high variation in the fish assemblage as river geomorphic features changed. Norden Chute (rkm 193), a natural fish barrier, marked a sharp change in geomorphic structure from a highly braided river with heterogeneous diversity of habitats downstream to a single river channel with a reduced floodplain upstream. Above the chute, the fish assemblage was dominated by insectivores fish species, while downstream occurrence of piscivores increased. Based on our results, fish barriers affected the diversity and abundances of fish both upstream and downstream