Theses and Dissertations

Issuing Body

Mississippi State University


Allen, Peter J.

Committee Member

Bosworth, Brian

Committee Member

Greenway, Terrence E.

Committee Member

Karsi, Attila

Date of Degree


Document Type

Graduate Thesis - Open Access


Wildlife, Fisheries and Aquaculture

Degree Name

Master of Science


College of Forest Resources


Department of Wildlife, Fisheries and Aquaculture


Channel catfish (Ictalurus punctatus) have a broad distribution from Canada to Mexico, suggesting that different strains may have different thermal tolerances. In aquaculture, daily temperature maximums up to 36-40°C and fluctuations of 3-6°C occur, and may be exacerbated by future climate change. To quantify differences in thermal tolerance amongst geographically-distinct channel catfish strains and corresponding hybrid catfish (I. punctatus x [blue catfish] I. furcatus): acute critical thermal maximum (CTmax), and the effects of chronic thermal regimes on growth, survival and differential gene expression were examined. Southern channel catfish had higher CTmax than northern, and channel catfish had higher CTmax than hybrid catfish. Under chronic thermal stress, hybrid catfish had the greatest survival and most consistent growth. Further, northern channel catfish had the greatest magnitude and largest amount of upregulated gene transcripts in response to high temperatures, indicating greater thermal stress. Therefore, catfish thermal tolerance varies by geographic region and species.