Kudos to Dr. Joel Snodgrass (yellow shirt) for turning me on to the blacknose dace as a research subject.
Locomotor performance can influence an animal's fitness by affecting foraging success, reproduction, and habitat selection . Thus, differential survival in some habitats may be a function of relative locomotor capacity. Physical performance has been shown to constrain behavioral and ecological options in lizards and snakes. Few studies have investigated the ecological role of variation in performance
among conspecific fish . Here we show that locomotor performance
of blacknose dace (Rhinicthys atratulus)
was found to tightly match the base flow conditions at the site they were captured from. Some of this work is described in the following publication:
Nelson, J.A. P. S. Gotwalt and J.W. Snodgrass. 2003. Current Velocity Structures Swimming Performance of Blacknose Dace (Rhinichthys atratulus). Canadian J. of Fish. Aquat. Sci. 60(3): 301-308.dacepap.pdf
Collecting Fish from Beaver Run, a rural stream in Carroll Co. Maryland
Fish of similar size from three local watersheds
were subjected to a modified critical swimming speed; fish were
exposed to increasing velocity increments of 5 cm/s at 5 minute
in
tervals.
Swim tunnel used to measure performance of dace
The modified Ucrit procedure used to test the fish was very repeatable. Below is a graph of a subset of dace swum a second time one month after the first swim without knowledge of their performance in the first swim.
Swimming performance tests were performed without knowledge of the base current flow at the sites where the fish were captured. Results revealed a positive, significant (p<.0001) relationship between mean base flow and mean Ucrit.See below:
This close coupling of swimming performance and base flow suggests an unprecedented structuring of animal capacity by environmental conditions in this species. Evidence from other fish studies suggests this coupling could be due to physiological plasticity or natural selection. Swimming performance has been shown to improve after training protocols, which suggests that physiological capacity is malleable.However, there is also evidence that natural selection can have divergent effects on geographically close populations.
Current work is focusing on whether these differences in swimming performance between geographically close dace populations are the product of physiological plasticity or natural selection.
Here you see undergraduate Chris Simonetti sprinting dace in a computer controlled sprint chamber with laser detection of fish position. See :
Nelson, J.A., P. S. Gotwalt , D.W. Webber and S. Reidy. 2002. Beyond Ucrit: Matching swimming performance tests to the physiological ecology of the animal, including a fish "drag strip". Comparative Biochemistry & Physiology. 133/2 pp 289-302
for a description of the sprint chamber.
Kirk Gastrich (left) and Portia Gotwalt, both did undergraduate research projects and then conitnued on for Masters degrees studying blacknose dace. Here you see them collecting dace from Gwynn's Falls, a BalBaltimore Co. suburban stream.
Portia helped establish the repeatability and flow dependencyof locomotor performance in this species & Kirk studied training of locomotor performance.
Results from Portia's Masters' thesis can be found in:
More recent research on dace in my lab has been carried out by these two very competent ladies, 
on the left is Nicole (Nikkii) Williamson who studied flow selection in individual blacknose dace in collaboration with Dr. Joe Cech (UC Davis). Little is known about what factors determine where fish from lotic environments will choose to locate. Since similar-sized individuals of a species can have substantially different swimming abilities, and interspecific differences in flow selection have been related to differential swimming abilities, one possibility is that an animal’s physical condition constrains the flow environments it chooses to occupy. Additionally, since the flow in an animal’s environment can contribute to its ability to swim, there could also be some environmental control over flow selection behavior. Nikki studied whether flow velocity selection by individual blacknose dace (Rhinichthys atratulus) is a repeatable trait in the laboratory, and whether it is a function of either the animal’s swimming ability or the magnitude of flow in their native stream reach. Blacknose dace from two populations, collected from each of two separate reaches with substantially different flows, exhibited significantly repeatable flow velocity selection over the course of a day in the laboratory. The flow velocity selected by the fish varied significantly among individual dace. Some of this variance was accounted for by fish from slow stream reaches choosing significantly faster flows than did those from faster reaches.
On the right of the picture is Kelly Taylor who studied temperature tolerance of blacnose dace:
As urbanization and climate change increasingly alter the temperature of many freshwater habitats, there is concern about how fish will thermally adapt. The standard method for testing thermal tolerance is the critical thermal maxima test (CTMax) wherein fish are exposed to gradually increasing temperatures in a static-flow aquarium. However, stream fish are subject to flow conditions that might alter their thermal tolerance. Kelly developed a new dynamic approach using a laminar flow swim tunnel to test the CTMax in blacknose dace and determined its efficacy by comparing it against a standard static method. Temperature tolerance in both tests was determined using a standard 0.3ºC/min temperature increment except that in the swim tunnel test fish were swum at 10cm/s . Individual dace at three different acclimation temperatures had almost identical tolerances to temperature under static and flowing conditions suggesting a neural rather than metabolic mechanism of thermoregulatory failure. We have also used this method to demonstrate the size independence of thermal tolerance in blacknose dace and have demonstrated a strict dependence of thermal tolerance on acclimation temperature.
Finally, the most recent research in dace in my lab has been carried out by visiting Italian scientist, Fabrizio Atzori, shown here on the far right styling in a bib and eating Maryland crabs. Fabrizio studied phenotypic plasticity of locomotor performance in dace, examining two types of locomotor performance in upstream and downstream populations from three watersheds as well as F1 individuals from the lab that had never experienced flow. Also shown are Stefano Marras (far left) currently post-docing in New York, and Khalid Srour, my former student and /ta from Jordan.