Suckers are medium-size fish that are well known to many anglers for their large lips. They belong to the family Catostomidae, which is closely related to the minnows.
Identification
Suckers are most easily distinguished by their inferior mouths and large fleshy lips. They have no barbels like catfish, no hardened spines in their dorsal or anal fins like perch and sunfish, and no adipose fins like trout. Suckers are robust fish, slightly laterally compressed. Most suckers are medium-size fish, but they range in adult size from only 6 inches (Roanoke hogsucker, Hypentelium roanokense) to more than 33 pounds (buffalo).Most suckers are not bright or distinctive in color. Many have an almost metallic sheen in shades of gold, green, purple, or white. Their coloration becomes more intense during reproduction, when many species darken in color and develop lateral stripes. Reproductive adults also develop hardened tubercles on their anal and caudal fins and heads. Young suckers typically have a more distinct color pattern, with several saddles on their backs and dark blotches on their sides for camouflage.
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Life history
Suckers inhabit all types of freshwater habitats, including rivers, lakes, and small streams. Most river species live in moderately fast-run habitats with moderate depths. The biggest suckers live in large lakes and deep pools in larger rivers.Because of their large size, suckers do not need to seek cover from predators, so they often coexist with bass and trout in deep pools. Despite popular belief, suckers are not fish that inhabit dirty, silty waters. In fact, most suckers require very clean substrate and are not tolerant of low dissolved oxygen.
Food
With inferior mouths and large, fleshy lips, suckers are well adapted to feeding on the bottom of streams or lakes. Most species suck up substrate and sift out small invertebrates and other organic materials. The most common foods are insects and worms, although some suckers are specialized for feeding on snails, vegetation, or crustaceans.Several species will also feed on detritus and will scrape algae from rocks. Suckers that feed on detritus, like the white sucker (see: Sucker, White), are the most widespread and abundant. Chubsuckers (genus Erimyzon) are midwater plankton feeders.
Age
Most suckers are moderately long lived, and the average life span is 8 to 15 years.Spawning behavior
Suckers become sexually mature at 2 to 3 years. A majority spawns in early spring, although some species continue into early summer. Many larger species make long migrations to the headwaters of rivers to spawn.They may come from farther down in the river or from adjacent lakes. These species spawn upstream, then the larvae hatch and drift downstream to recolonize lower stream reaches. Suckers typically need clean gravel substrate in which to spawn. This type of habitat usually occurs at the tail ends of pools, in riffles, and in gravel bars.
Most sucker species spawn in large aggregations. Several males may spawn with the same female at the same time. Many suckers spawn in a trio, with a female flanked by two smaller males. The males align next to the female in a suitable location in a riffle or pool tail. Then all three individuals shake violently as sperm and eggs are released.
This shaking allows the fish to dig down into the substrate and bury the newly deposited eggs. Only one species of sucker, the river redhorse (Moxostoma carinatum), actually prepares a redd as trout do, but many do move around much gravel as they dig into the stream bottom. Suckers produce many small eggs and provide little or no parental care.
