Re: NANFA-L-- Sculpin temperature tolerance

Michael Sandel (kwksand at
Thu, 15 Sep 2005 15:17:55 -0700 (PDT)

Hey Todd and others,

This information was posted by Dave Neely in 1997. The species are probably comparable in adaptability, but individual gene expression is controlled by local conditions. i.e.- an individual raised in a warm stream is probably more heat tolerant than an individual from a cold stream, regardless of latitude or species.

Steve Walsh et al. (1997) examined the thermal tolerance and metabolism of
several sculpin taxa from the SE US.

Sculpins were held at stepped acclimation temperatures of 10, 15, 20, and 25
deg C for between 2-72 weeks, then tested for critical thermal maxima
(defined as the temp at which fish would not right themselves after being
flipped over), and metabolic rates.

They did not find intraspecific differences in thermal tolerance between
Tallapoosa sculpin, banded sculpin, Ozark sculpins, or "mottled sculpin"
(they used "smoky sculpins" from the upper Etowah). Pygmy sculpins and
mottled sculpins had lower critical thermal maxima than all other taxa
examined. All species examined exhibited significant differences in
temperature tolerance across acclimation temperatures, suggesting that
localized populations which are used to high temps would be more able to
withstand such conditions in aquaria.

The complete citation for those interested parties is:
Walsh, SJ, DC Haney, and CM Timmerman. 1997. Variation in thermal tolerance
and routine metabolism among spring and stream-dwelling freshwater sculpins
(Teleostei: Cottidae) of the southeastern United States. Ecology of
Freshwater Fish 1997(6):84-94.

/ This is the discussion list of the North American Native Fishes
/ Association (NANFA). Comments made on this list do not necessarily
/ reflect the beliefs or goals of NANFA. For more information about NANFA,
/ visit Please make sure all posts to nanfa-l are
/ consistent with the guidelines as per
/ To subscribe, unsubscribe, or get
/ help, visit the NANFA email list home page and archive at