Factors Limiting Overwinter Survival of Young-Of-The-Year Largemouth Bass in South Dakota

Studies were conducted to examine the effects of total length (TL), prey abundance, and water temperature on approximate body composition, condition index, and overwinter survival of young-of-the-year (YOY) largemouth bass Micropterus salmoides in South Dakota. Growth and condition of YOY largemouth bass stocks from South Dakota and Wisconsin were also compared. Study areas included two South Dakota University impoundments (0.8 hectare each), a gravel pit (7. 3 hectare), and laboratory aquaria. Hatchery reared YOY largemouth bass were graded into short (19-45 mm TL) and long (58-135 mm TL) length groups. Overwinter mortality was 78% and 85% in the two impoundments, and 100% in the gravel pit. Overwinter mortality in all study sites my be related to insufficient energy reserves. Overwinter survival, proximate body composition and condition index were similar between short and long fish and among impoundments. Moisture (P<0. 0001) content of fish in the field study differed over time. The trend was lower from August (85%) through October (76%), with little change overwinter. Lipids (P<0. 007) and relative condition (Kn) (P<0. 0002) also differed over time. The trend in lipids was an increase from August (11%) through September (18%) and a decrease to 12% by March. The decline in lipids was five time greater for fish in the pond having a lower prey abundance than for fish in the pond which did not. Lipids and relative condition (Kn} were strongly correlated (r=0. 9999, df=2, P<0. 001) and were best fit with a curvelinear relationship. In the laboratory study fed fish showed higher lipids (P<0. 0001) and Kn (P<0. 0001), and lower moisture (P<0. 0001} and ash (P<0. 0001) than fasted fish. lipid (P<0. 02), moisture (P<0. 004) and ash (P<0. 01) differed between short and long fish. Fish at 4°C had higher moisture (P<0. 004) and lower lipids (P<0. 01} then fish at 10°c. Length, weight, proximate body composition, relative condition (Kn), Liver Somatic Index (LSI), and Mesenteric Fat Index (MFI) were not different between the Wisconsin and South Dakota stocks of YOY largemouth bass in two South Dakota impoundments.

Name thesis:degree_name

Master of Science (MS)

Level thesis:degree_level

Thesis - Open Access

Discipline thesis:degree_discipline

Wildlife and Fisheries Science

Year

1992

Author dc:creator

• Kolander, Todd D.

Contributors dc:contributor

• Charles R. Berry

• Natural Resources and Conservation

Statement dc:rights

• Copyright © 1992 Todd D. Kolander. All rights reserved.

Language dc:language

en

Repository record dc:identifier

https://openprairie.sdstate.edu/etd/506

OAI identifier oai:identifier

oai:openprairie.sdstate.edu:etd-1506