Rock Bass

Rock Bass Ambloplites rupestris

Type of Animal:

Clear rocky stream pools, clear rocky vegetated lake margins, rocky lake banks, rocky reservoir banks, rocky shorelines, rocky-bottom human swimming areas, rocky-bottom lakeside docks, stone/rubble-covered rivers, rocky hard-bottom lakes, rocky hard-bottom lake coves, rubble/rock-strewn points in hard-bottom lakes, hard-bottom rocky lake reefs, deep stone/rubble-covered river pools, nearshore stone/rubble-covered river eddies, river pockets behind boulders/ledges/shaded shoreline spots, river logs/deadfalls/underwater stumps, reservoirs, vegetated rivers, vegetated lakes, vegetated ponds, vegetated streams, lightly vegetated gravel bars, gravel shorelines, breakwaters, rocky reservoir shores w/ permanent flow/silt-free bottom, rocks/rocky areas, logs, woodcover/bulrush covered lakes, pondweed lake flats, stagnant to slow-flowing rocky vegetated brushy stream margins, stagnant to slow-flowing rocky vegetated creek pools, stagnant to slow-flowing rocky vegetated canals, stagnant to slow-flowing rocky vegetated backwaters, irrigation channels

Native to C/E US & C/E Canada. Introduced/invasive throughout continental US, Mexico, & France’s Loire Valley.

Golden brown to olive colored fish w/ white to silver belly & dark spotting, red eyes, large mouth, dark teardrop shaped area around each eye, can change color to match surroundings

Crustaceans, smaller fish (including younger members of own species), insects, insect larvae, worms, leeches, aquatic plant matter

Status in Wild:

Not applicable

Schools of 10-40 fish. Colonial nesters w/ each nest guarded by territorial male. Juveniles found in even larger schools.

Additional Info:

Young: Fry/Fingerling
Group: School
Male: 4.8-16 oz
Female: 3.2-8 oz
4 days 

Life Span:
5-10 years

Body Length:
Male: 7-10.5 in
Female: 6-8 in
Young: 3 in

Tail Length:
2.5 in, same for both sexes

Main predators are larger bass, pike, muskies, walleye, alligators, fish-eating birds, snapping turtles, & fish-eating mammals.
They lack courtship displays, so females just enter male nest, w/ them simultaneously releasing sperm/eggs.
Spawn in spring.
They often compete w/ larger Smallmouth Bass.
Also called Northern Rock Bass, Google Eye, Redeye Bass, Redeye, Perch, Sunfish, & Rock Perch.

Fun Fact(s):
Single female can lay anything from 2,000-11,000 eggs per season. Females lay eggs in multiple nests & nests usually contain eggs from many females. Male guards eggs/fry aggressively, even charging at people who come too close. Many males lose weight & even die during/after this period due to not eating.
Popular gamefish in many areas but often treated in lesser manner compared to other popular gamefish.

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