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Full-Text Articles in Ecology and Evolutionary Biology

Characteristics Of A River Otter (Lontra Canadensis) Maternal Den In The Central Platte River Valley, Ne, Jenna M. Malzahn, Andrew J. Caven, Joshua D. Wiese Aug 2020

Characteristics Of A River Otter (Lontra Canadensis) Maternal Den In The Central Platte River Valley, Ne, Jenna M. Malzahn, Andrew J. Caven, Joshua D. Wiese

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

River otters (Lontra canadensis) encompass a broad geographic range including coastal, riverine, and lacustrine systems. However, knowledge of reproductive behavior and structural den characteristics remain relatively few in the literature, particularly in the Great Plains. Distinctions between the terms “den”, “den site”, “natal den”, and “maternal den” are often ambiguous, obscuring our understanding of river otter’s young-rearing behavior. We used observations and descriptions regarding a single maternal den site and a broad reading of the mustelid literature to propose a more standardized maternal den definition for river otters and specify hypotheses for future research. From 25 April to …


The Status Of Fishes In The Missouri River, Nebraska: Selected Ancient Fishes, Kirk D. Steffensen Dec 2015

The Status Of Fishes In The Missouri River, Nebraska: Selected Ancient Fishes, Kirk D. Steffensen

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

Several ancient fish species have inhabited the Missouri River and its tributaries for thousands of years prior to major mainstem modifications and fragmentation. However post-anthropogenic modifications, populations of these ancient fish species have been highly diminished. Therefore, the objective of this study was to use historic and current ichthyological records to determine the past and present status for Chestnut Lamprey Ichthyomyzon castaneus, Silver Lamprey Ichthyomyzon unicuspis, Bowfin Amia calva, American Eel Anguilla rostrata, and Burbot Lota lota. Currently, these species are rarely captured and perhaps extirpated from Nebraska waters.


The Status Of Fishes In The Missouri River, Nebraska: Shoal Chub (Macrhybopsis Hyostoma), Sturgeon Chub (M. Gelida), Sicklefin Chub (M. Meeki), Silver Chub (M. Storeriana), Flathead Chub (Platygobio Gracilis), Plains Minnow (Hybognathus Placitus), Western Silvery Minnow (H. Argyritis), And Brassy Minnow (H. Hankinsoni), Kirk D. Steffensen, Dane A. Shuman, Sam Stukel Dec 2014

The Status Of Fishes In The Missouri River, Nebraska: Shoal Chub (Macrhybopsis Hyostoma), Sturgeon Chub (M. Gelida), Sicklefin Chub (M. Meeki), Silver Chub (M. Storeriana), Flathead Chub (Platygobio Gracilis), Plains Minnow (Hybognathus Placitus), Western Silvery Minnow (H. Argyritis), And Brassy Minnow (H. Hankinsoni), Kirk D. Steffensen, Dane A. Shuman, Sam Stukel

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

Throughout the past century, the Missouri River has been highly modified which has negatively affected the native fish community. Previous research quantified the reduction of several native Cyprinidae species and made several recommendations to aid in recovery. However, these recommendations were not implemented. Therefore, the objective of this paper is to assess the current population trends of eight native cyprinid species and develop the current management objectives. Over 335,000 fish were collected from the Missouri River along Nebraska’s eastern border with mini-fyke nets and otter trawls from 2003 to 2012. Target Cyprinidae species consisted of less than five percent (n …


The Status Of Fishes In The Missouri River, Nebraska: Sauger (Sander Canadensis), Kirk D. Steffensen, Sam Stukel, Dane A. Shuman Dec 2014

The Status Of Fishes In The Missouri River, Nebraska: Sauger (Sander Canadensis), Kirk D. Steffensen, Sam Stukel, Dane A. Shuman

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

Early fisheries investigation of the Missouri River fish community indicated that Sauger were common throughout Nebraska, including all major Missouri River tributaries. However due to many factors, their current range is restricted to the Missouri River and the lower reaches of a few tributaries. Hesse (1994) recommended listing Sauger as a state endangered species but this recommendation was never implemented. Therefore, the objective of this paper is to reevaluate the current population status of Sauger in the Missouri River along Nebraska’s border. Over 2,100 Sauger have been captured from the Missouri River along Nebraska’s eastern border since 2003. Sauger were …


The Status Of Fishes In The Missouri River, Nebraska: Lake Sturgeon (Acipenser Fulvescens), Kirk D. Steffensen, Sam Stukel, Dane A. Shuman Oct 2014

The Status Of Fishes In The Missouri River, Nebraska: Lake Sturgeon (Acipenser Fulvescens), Kirk D. Steffensen, Sam Stukel, Dane A. Shuman

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

Lake Sturgeon (Acipenser fulvescens) occurrences in the Missouri River along Nebraska’s eastern border are historically sporadic and rare. Presently, the wild Lake Sturgeon population in this river reach may be extirpated. A Recovery Program initiated by the Missouri Department of Conservation (MDC) has stocked almost 150,000 hatchery-reared Lake Sturgeon into the lower Missouri River at several sites in Missouri. As a result, the number of Lake Sturgeon collected has increased. Since monitoring began in 2003, no Lake Sturgeon have been collected above Gavins Point Dam while 40 fish were collected downstream of Gavins Point Dam. The majority of …


The Status Of Fishes In The Missouri River, Nebraska: Pallid Sturgeon (Scaphirhynchus Albus), Kirk D. Steffensen, Dane A. Shuman, Robert A. Klumb, Sam Stukel Sep 2014

The Status Of Fishes In The Missouri River, Nebraska: Pallid Sturgeon (Scaphirhynchus Albus), Kirk D. Steffensen, Dane A. Shuman, Robert A. Klumb, Sam Stukel

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

Anthropogenic alterations to the Missouri River have placed the Pallid Sturgeon (Scaphirhynchus albus) population in jeopardy and contributed to their listing as an endangered species. Pallid sturgeon were always less common than the sympatric Shovelnose Sturgeon (S. platorynchus); however, Pallid Sturgeon seemed to be more affected by river alterations as the river sturgeon ratio has become more skewed towards Shovelnose Sturgeon. Shortly after listing, population augmentation with hatchery produced Pallid Sturgeon began to supplement the diminishing wild population. Therefore, the objective of this study was to present the current population status of the Pallid Sturgeon in …


The Status Of Fishes In The Missouri River, Nebraska: Shovelnose Sturgeon (Scaphirhynchus Platorynchus), Kirk D. Steffensen, Sam Stukel, Dane A. Shuman Sep 2014

The Status Of Fishes In The Missouri River, Nebraska: Shovelnose Sturgeon (Scaphirhynchus Platorynchus), Kirk D. Steffensen, Sam Stukel, Dane A. Shuman

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

The Shovelnose Sturgeon Scaphirhynchus platorynchus remains the most abundant riverine sturgeon species in North American despite the anthropogenic modifications that have occurred throughout their historic range; however, their populations have declined throughout Nebraska since the construction of Fort Randall and Gavins Point Dams. Therefore, the objective of this study was to present the current status of Shovelnose Sturgeon in the Missouri River along Nebraska’s border. Data was acquired from 2003 to 2012 from all reaches of the Missouri River along Nebraska’s eastern border. Catch rates of Shovelnose Sturgeon increased in a downstream trend and were highest in the reach below …


Morphological Variation Of Allocreadium Lobatum (Digenea: Allocreadiidae) In The Creek Chub, Semotilus Atromaculatus (Osteichthyes: Cyprinidae), In Nebraska, Usa, Monte S. Willis Jan 2002

Morphological Variation Of Allocreadium Lobatum (Digenea: Allocreadiidae) In The Creek Chub, Semotilus Atromaculatus (Osteichthyes: Cyprinidae), In Nebraska, Usa, Monte S. Willis

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

Allocreadium lobatum Wallin 1909, a parasite of fresh-water fish, was originally described as having distinct lobate testes, and subsequent descriptions have left this original description unchanged. The present study quantifies the observation of distinctly non-lobate testes that could be categorized as round or asymmetrical in addition to the previously described lobate testes. Six hundred thirty-six A. lobatum were collected from 228 Semotilus atromaculatus over a 9 month period. Overall, 21.3%, 61.6%, and 16% were found to be round, asymmetrical, and lobate testes respectively (N = 1,071). Analysis of testis morphology found the increasing presence of lobate testis as …