The Effects of Temperature on Feeding and Expression of Two Appetite‐related Factors, Neuropeptide Y and Cocaine‐ and Amphetamine‐regulated Transcript, in Atlantic Cod, Gadus morhua

In vertebrates, including fish, environmental temperature influences feeding through mechanisms that are unclear. We investigated the effects of three different temperatures on food consumption and brain messenger RNA (mRNA) expression levels of two hypothalamic appetite‐regulating factors, neuropeptide Y (NPY) and cocaine‐ and amphetamine‐regulated transcript (CART), which stimulates and inhibits feeding, respectively. Atlantic cod acclimated to 2 C for 4 wk had a decreased food intake and higher CART brain mRNA levels compared to fish acclimated to 11 and 15 C. No differences were seen in NPY mRNA expression between the three groups. Our results suggest that in cod, low temperatures inhibit food intake, and this inhibition is in part mediated by an increase in CART expression but does not involve changes in NPY expression.