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ARS Home » Southeast Area » Stoneville, Mississippi » Warmwater Aquaculture Research Unit » Research » Publications at this Location » Publication #416929
Research Project: Improving the Productivity and Quality of Catfish Aquaculture

Location: Warmwater Aquaculture Research Unit

Title: Changes in physiology and stress responses of pellet-reared largemouth bass fed live-forage diets

Author
item ALLEN, PETER - Mississippi State University
item DINKEN, COLIN - Mississippi State University
item KERETZ, KEVIN - Mississippi State University
item SCHRAMM, HAROLD - Mississippi State University
item PETRIE-HANSON, LORA - Mississippi State University
item SCHILLING, M - Mississippi State University

Submitted to: North American Journal of Aquaculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/6/2019
Publication Date: 10/28/2019
Citation: Allen, P.J., Dinken, C.P., Keretz, K.R., Schramm, H.L., Petrie-Hanson, L., Schilling, M.W. 2019. Changes in physiology and stress responses of pellet-reared largemouth bass fed live-forage diets. North American Journal of Aquaculture. 82:2-23. https://doi.org/10.1002/naaq.10120.
DOI: https://doi.org/10.1002/naaq.10120

Interpretive Summary: Largemouth bass are increasingly reared in aquaculture operations in the US using commercial formulated, pelleted diets. This study was conducted to determine how closely hatchery-reared largemouth bass approximate wild fish, and how long fish must be fed a natural diet before they more closely approximate wild fish. Many stress responses were similar between wild and hatchery-raised fish, but a time duration of 4-6 weeks of natural diet was required before most physiological variables were similar.

Technical Abstract: Advanced-sized Largemouth Bass Micropterus salmoides to be used for stocking and experimentation can be ef'ciently reared on prepared feed in intensive culture conditions, but formulated diets containing high levels (=20%) of dietary carbohydrates may lead to high liver and muscle lipid and high liver glycogen levels, which may affect survival and stress responses. Largemouth Bass were raised to a size of 240–344 mm TL on formulated diets and then were fed live forage (i.e., naturalization); the effects of naturalization on liver, blood, and muscle health indices and physiological stress measures were evaluated, and indices were compared with those of wild Largemouth Bass from three different reservoirs. Hepatosomatic index (HSI) decreased by week 1 of naturalization; liver glycogen decreased by week 2; liver lightness, yellowness, and steatosis decreased by week 4; and liver moisture and lipid concentration stabilized after 4 weeks Plasma cortisol was higher by week 1 of naturalization than by week 6 and onward, and plasma pH decreased after 1 week. Muscle color showed changes by week 1 of naturalization, muscle collagen stabilized by week 4, and muscle lipids decreased more gradually compared to the liver. The mag-nitude of stress response in 'sh subjected to a 60-s chasing stressor was unaffected by naturalization. Among populations of wild 'sh, many liver, blood,and muscle metrics were similar, with the exception of liver yellowness, glycogen, and HSI; muscle redness, lipids, and moisture; and the viscerosomatic index. Therefore, after rearing on a high-carbohydrate, high-lipid diet (i.e., 20% carbohydrates; 16% lipids), 4–6 weeks of naturalization can improve liver health with most liver parameters being similar to those found in populations of wild 'sh.