Two Suckers

     I have often seen two kinds of adaptable fish called white suckers and northern hog suckers in certain streams here in southeastern Pennsylvania.  A couple of times I've watched white suckers spawning over gravel in the shallows of streams early in April.  Spawning males had pink on their flanks and fins.  And I've seen hog suckers pushing their big heads into stream bottom gravel to expose insect larvae, crayfish and other kinds of invertebrates.
     Both these types of suckers commonly live in streams and creeks in the eastern half of the United States.  In spring they spawn in the rocky shallows of those waterways, scattering their eggs randomly among the stones.
     Suckers have down-turned mouths, which allows them to efficiently eat invertebrates, fish eggs and aquatic vegetation from stream bottoms.  Small, young suckers ingest zooplankton and algae from those same waterway bottoms.  Suckers' feeding on stream bottoms reduces competition for food with other species of fish that share waterways with them.  Great blue herons, bald eagles, ospreys, mink and other fish eaters consume suckers, making them part of several food chains.
     White suckers are plain and silvery, and can grow to be 24 inches long and about five pounds in weight.  These adaptable fish can tolerate some pollution, silt, warm water and low oxygen in their streams.  And they can live in ponds as well as running waterways.
     White suckers are a fighrting fish if caught on a hook.  And they are reputed to be good eating.
     Hog suckers are a clean-bottom-only fish, including the cold water of trout and minnow streams with their numerous, gravelly riffles.  None of these fish species can tolerate much pollution.  The presence of hog suckers, trout and minnows in a stream indicates good water quality.  
     Hog suckers can be up to 22 inches long and weigh about four pounds.  They are brown with darker stripes over their backs and down their flanks, coloration that allows them to blend in with their surroundings, which helps keep them safe from predators.  Their lower fins, however, are dull red.  They also have large, sturdy heads they use to turn stones over to get invertebrates.
     Hog suckers spawn over stones in shallow, running water.  Much thrashing and splashing is associated with their egg-laying.
     Hog suckers live with and resemble minnow-sized Johnny darters on the stony bottoms of streams.  Hog suckers and darters are the same colors and color patterns for camouflage on waterway gravel.  Both kinds of fish rest on their fins on stream bottoms, but dart away when disturbed.  Their similar adaptations to a mutual niche is called convergence.
     The two common sucker species of southeastern Pennsylvania are each interesting in their own way.  When along a gravelly stream, watch for these species of fish, as well as other kinds of interesting creatures.