Pike CNHI - Pennsylvania Natural Heritage Program

Fishes of Pike County
Fish live in a variety of aquatic habitats, such as ponds, streams, rivers, reservoirs, and lakes. Anglers
appreciate sport fishes such as brook trout and smallmouth bass, but there are over 160 fish in the
Commonwealth, many of which eat, reproduce, and occupy their habitats in unique and fascinating ways.
Fish can be voracious eaters of other fish or gentle grazers of plants. Many fish are predators of insects, while
others eat mollusks, crayfish, salamanders, or frogs. Some fish eat only algae throughout their lives.
Many fish species migrate to spawn. Upstream habitats are important for spawning and the development of
young fish. Access to spawning habitats is inhibited by dams along the migratory paths of fish, despite fish
ladders on some large dams. Dams on the tributaries to the Delaware River prevent fish migration in many
streams. However, the free-flowing Delaware River provides a migratory route for American eels (Anguilla
rostrata) on their long distance travels from their breeding grounds in the Sargasso Sea in the Atlantic Ocean
to the habitat for juveniles and adults in the freshwaters of the coastal watershed.
Nests are created by some fish to protect their young. River
chubs (Nocomis micropogon) assemble piles of gravel up to
24 inches wide, while trout make nests called “redds” which
are trough-like depressions in the stream bottom, oriented to
supply oxygen to the developing fish. Channel catfish
(Ictalurus punctatus) lay their eggs in undercut banks, on
sunken logs, or in abandoned muskrat holes. Sunfish, such
as bluegills (Lepomis macrochirus), create depressions in
sand and gravel on the stream bottom. The adult fish guard
the developing eggs from predators and later defend the
young larvae until they are able to fend for themselves.
Pumpkinseed (Lepomis gibbosus)
Habitat provides food resources and shelter for fish. Bottom
dwelling fish prefer to swim near the rocks and logs that line the stream beds. Sculpins and darters, adapted to
the life on the stream bottom, rest their fins on the substrate and eat insects that cling to the rocks. Other fish
prefer to swim the open waters or among vegetation at the shores of rivers and lakes.
The fish found in Pennsylvania’s flowing waters have distinct habitat preferences; the two most important
factors of habitat are stream size and water temperature. The typical habitats of streams and rivers are
classified as:
• Headwater streams are the smallest streams, and water temperatures are often cold (75F) and slower flows. Pools and runs become
more prominent than riffles. These streams usually have “Warmwater Fish Communities,” with central
stonerollers (Campostoma anomalum), northern hogsucker (Hypentelium nigricans), sunfish (Lepomis spp.),
smallmouth bass (Micropterus dolomieu), and a variety of other darters and minnows.
• Large rivers, such as the Delaware River, usually have warmer, slower waters. When there are dams, the
habitat can be similar to lake conditions. Since large rivers usually flow through well-populated areas, they
often receive many pollutants and have multiple threats to water quality. Rivers may have “River and
WPC
Pike County Natural Heritage Inventory – Animals of Pike County / 31