Document Type

Thesis - Open Access

Award Date

1992

Degree Name

Master of Science (MS)

Department

Wildlife and Fisheries Science

First Advisor

Charles R. Berry

Abstract

Few sturgeon chub (Macrhybopsis gelida: Cyprinidae) have been collected in the last decade, therefore their status, habitat selection and morphology were investigated at 172 previous collection sites. Data on two ecologically similar species, Platygobio gracilis and Rhinichthys cataractae, were also collected. Macrhvbopsis gelida were collected at 28 sites on the Powder River (n = 158) in Wyoming and Montana, and at one site on the Yellowstone River (n = 1) in Montana. Age-I, Age-II and Age-III M. gelida were collected. Specimens were 37 to 95 mm in total length. Macrhvbopsis gelida were ripe in mid-June, at water temperatures of 18.3-22. 2°C, and produced about 5, 000 eggs. Sites where M. gelida were collected in the Powder River typically had flows > 0.35 m/sec and substrates with ≥ 40% gravel/rubble. Percent species composition of M, gelida at riffle sites on the Powder River declined from 28% in 1979-80 to about 3% in 1989-90 . Morphometric characters of M. gelida were similar throughout the Powder River, except for head width, snout length and body depth. Counts of M. gelida anal, dorsal, pelvic and pectoral fin rays; lateral line scales; and scale rows above and below the lateral line were significantly (P ≤ 0.05) different among three sections of the Powder River. No M. gelida x M. aestivalis hybrids were found. Platygobio gracilis (n = 8, 889) and R. cataractae (n = 2,857) were more widely distributed and more abundant than M. gelida and distinct habitat associations were not identified. Morphometric characters of£. Gracilis and R. cataractae with significant (P ≤ 0.05) differences among rivers were: anal and dorsal fin base lengths; pelvic, pectoral and dorsal fin lengths; caudal peduncle depth; eye diameter; head length and width; snout length; and body depth. Platygobio gracilis and R. cataractae from the Little Missouri River in North and South Dakota had longer anal and dorsal fin bases; longer pelvic, pectoral and dorsal fins; longer heads and snouts; and deeper caudal peduncles than specimens from other streams in the Missouri River Basin. Meristic characters of E. gracilis and R. cataractae with significant (P ≤ 0.05) differences among rivers were: anal, dorsal, pelvic and pectoral fin rays; lateral line scales; and scale rows above and below the lateral line. No subspecies of£. gracilis or R. cataractae were identified, however, R. cataractae showed the greatest tendency for subspeciation.

Library of Congress Subject Headings

Fish populations -- Missouri River Basin
Freshwater fishes -- Missouri River Basin

Description

Includes bibliographical references (page 48-55)

Format

application/pdf

Number of Pages

63

Publisher

South Dakota State University

Rights

Copyright © 1992 Selena J. Werdon. All rights reserved.

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