Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)


Wildlife and Fisheries Science


Aquatic macrophyte removal by herbivorous fishes was investigated to determine changes in the predator-prey relationship of largemouth bass, Micropterus salmoides, and bluegills, Lepomis macrochirus, stocked into 15 prairie ponds. Monosex grass carp, Ctenopharyngodon idella, and hybrid grass carp, Ctenopharyngodon idella x Hypophthalmicthys nobilis, were each stocked at a rate of 247 fish/hectare into five study ponds. Largemouth bass and bluegills were each stocked into 12 study ponds at 247 fish/hectare in July, and 1235 fish/hectare in September, 1984, respectively. Additional largemouth bass were stocked at a rate of 247 fish/hectare into nine study ponds in July, 1985. Conductivity was the only water quality variable which differed significantly (P<0.05) due to treatments. Substantial, but not significant (P>0.05), differences in vegetation removal were observed among ponds. The failure to detect statistical differences likely resulted because of greater variability among ponds within treatments than between treatments. Vegetation removal appeared to be greatest in the monosex grass carp treatment with slight differences between the control and hybrid grass carp treatment ponds. Water transparency declines, as measured by secchi disc visibility and turbidity, were greatest in the monosex grass carp treatment. The evaluation of vegetation removal on largemouth bass-bluegill interactions was not possible because of the failure of bluegills to reproduce. Survival of stocked bluegills was low as a result of small stocking length. Mean survival rate for age-I largemouth bass was 38% for eight ponds. Mean growth and mean Wr for age-I largemouth bass was 160 nm and 119 g, respectively. Abundance of age-0 largemouth bass appeared to be influenced greater by the survival rate of age-I largemouth bass than by vegetation abundance.

Library of Congress Subject Headings

Fish stocking -- South Dakota
Water -- Microbiology -- South Dakota
Fish habitat improvement


Includes bibliographical references (pages 44-51)



Number of Pages



South Dakota State University


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