Oscar
Astronotus ocellatus

Description: Brightly colored with irregular red markings on a dark brown body; prominent black spot surrounded by red ring at base of caudal fin.
Size: Weight reaches 3 pounds or more; state record 2 pounds 6 ounces.
Distribution: O`ahu.
Habitat: Prefers quiet shallow water.
Feeding: Feeds on small fish, crayfish, worms and insect larvae.
Life history: Spawning in Hawai`i occurs from about March to September; oscar pairs excavate a circular nest in shallow water, where eggs are deposited; both parents guard the nest.
Fishing methods: Minnow like lures are effective; live baits include worms, crayfish and mosquitofish.
Introduced to Hawai`i in 1951.

Pongee (snakehead)
Channa striata

Description: Dark mottled coloration on top and sides mixing black with yellow‑orange, white below; very large scales and slimy to the touch; eel‑like in appearance; excellent eating.
Size: Adults average 2 feet in length and 3 pounds in weight; largest known to have been taken in Hawai`i exceeded 5 feet in length.
Distribution: O`ahu; abundant in Wahiawa Reservoir and other reservoirs on the north side of the island.
Habitat: Prefers calm near shore waters and will often float with debris; an obligate air breather, it will suffocate if held under the water on a stringer.
Feeding: A voracious predator, its feeding habits are similar to largemouth bass.
Life history: Spawning occurs during the spring and is limited to reservoir or pond habitats; one or both parents will guard the young for several weeks.
Fishing methods: Same as for largemouth bass.
Introduced to Hawai`i in the early 1800s.

Warning: Do not put your thumb in fish's mouth. In addition to the teeth on its jaw, it has large backward‑pointing teeth on the roof of its mouth that can inflict deep wounds.

Puntat (Chinese catfish)
Clarias fuscus

Description: Coloration ranges from dark green to brown to black; flesh dark red; no scales; excellent eating.
Size: Average weight about 1 pound; maximum about 2 pounds.
Distribution: Abundant in streams and reservoirs throughout Hawai`i.
Habitat: Reservoirs and lower to middle reaches of streams; a facultative air breather, its presence may be betrayed by small geysers of water that erupt when it surfaces for air; preference for deep water or dark crevices makes it rarely visible to casual observers.
Feeding: Worms, insects and carrion comprise the diet of these opportunistic feeders.
Life history: Spawning occurs year round under normal conditions; In the event of drought it can survive for weeks in damp mud.
Fishing methods: Worms are the favored live bait; artificial lures are ineffective.
Introduced to Hawai`i in the early 1800s.

Carp (Koi)
Cyprinus carpio

Description: Brassy olive above, yellowish on sides and belly in wild form; domesticated koi may exhibit a wide range of brilliant colors; scales large but may vary in form; one variety (leather carp) has no scales; easily differentiated from goldfish by a pair of moderately long barbels at corners of mouth.
Size: Weight up to 20 pounds in Hawai`i; world record 75 pounds 11 ounces (France).
Distribution: Present in reservoirs on all islands.
Feeding: Omnivorous; root up the bottom when they feed.
Life history: Spawn in spring and summer in Hawai`i; transparent adherent eggs are broadcast or clumped on nearshore substrate; parents do not protect the young.
Fishing methods: Doughballs or corn are favored.
Introduced to Hawai`i in the 1800s.

Tilapia
Oreachromis mossambicus

Description: The most common of the four species of tilapia deliberately introduced to Hawai`i; generally a grey to dark coloration; spawning males are black; concave head shape; red fringe on dorsal fin; large scales. Although there is a local prejudice against the fish, it is in fact good eating (depending on the water it is taken from) and is raised commercially in many areas of the world.
Size: Average weight about 1 pound; maximum 5 pounds.
Distribution: Abundant in reservoirs, lower streams and brackish waters statewide.
Feeding: Primarily herbivorous, but also an opportunistic scavenger.
Life history: Breeds throughout the year but more intensively during the warmer months; digs nests for spawning; female incubates the eggs in her mouth; at moments of danger the fry continue to take refuge in the mother's mouth for a week or more after hatching.
Fishing methods: Worms and doughballs are effective bait.
Introduced to Hawai`i in 1951.