An adult tadpole madtom is typically 2–3 inches (50–80 mm), however they have recorded at a length of 5 inches (130 mm).
The tadpole madtom is found in parts of the U.S. and Canada. In Canada it is native to Manitoba, Ontario, Quebec, and Saskatchewan, and can be found the Assiniboine, Saskatchewan, Souris, Red, English, Winnipeg, and Nelson rivers. The tadpole madtom's range in the United States is extensive, ranging from Texas to Florida and north along the Atlantic coast to New York. It can be found in the Mississippi River valley as well as the Great Lakes basin. In Minnesota it is present in all adjacent drainage systems to the Red River basin. In North Dakota it can be found in the Missouri river drainage. In South Dakota it is present in the eastern tributaries to the Missouri River, including the James River, as well as the Minnesota and Big Sioux river drainages.
The tadpole madtom lives in areas with little to no current. They typically inhabit swamps and marshes, as well as lakes and slow moving streams and rivers 0.1–1.5 meters deep and 12–24 meters wide. They also prefer habitats with turbid water; a soft mud, sand or gravel bottom; and thick vegetation to use for crypsis.
The tadpole madtom is an invertivore, planktivore, but also feeds on particulate. A Common food source for the tadpole madtom are immature insects such as cladocera, ostracods, hyalella, and chironomids. Another popular food source is small crustaceans such as amphipods and isopods. Smaller fish feed more on small crustaceans while large fish tend to consume large prey such as worms and grass shrimp. Researchers in Wisconsin recorded the stomach contents of numerous tadpole madtoms and found an average diet consisting of 44% insects, 28.3% small crustaceans, 18.3% oligochaetes, 5.9% plants, 3% silt and debris, 0.1% snails, and 0.1% algae.
James Landreth wrote:I think crayfish could, if you count them
This species can reach a length of 5.9 cm (2.3 in), though most are only about 4 cm (1.6 in).
The swamp darter ranges from Southern Maine along the Atlantic Coast and Gulf Coast to about the Texas-Louisiana border and north in the former Mississippi Embayment to Kentucky.
The swamp darter is found in stagnant swamps, bogs, and man-made ponds or slow-flowing, sluggish streams, especially where detritus or aquatic vegetation occurs over mud. Fish color is related to water color; the darkest individuals are in dark-water coastal streams and ponds. It lives in water in which the lower pH values are not typically tolerated by all but a few freshwater species of fish. It also tends to thrive in alkaline waters of northern Florida. The range of water temperature tolerated between Maine and Florida is also impressive.
Swamp darters feed on fly larvae, amphipods, and other small crustaceans and insects. Swamp darters tend to be an important element in the diets of young chain pickerel and young largemouth bass, where the species coexist. Human-induced problems for this hardy, widespread, and locally abundant darter do not seem to exist. It thrives under a variety of conditions, including warm water, extreme murkiness or brown coloration, low or high pH, and low oxygen content.
Hester Winterbourne wrote:My question would be - for what purpose do you want fish in this pond? Is it as a crop for your own or some other animal's consumption? Or is it because you think a pond "needs" fish to make it a functioning ecosystem? I would argue not. Lots of small ponds in nature dry up annually so cannot support (most) fish but are ideal for amphibians which contribute to the surrounding ecosystem.
Dan Scheltema wrote:I would love to see some pics of your small ponds, Steve.