Crenicichla cyclostoma, Ploeg 1986
Distribution: Rio Tocantins, Brazil.
Size: 4 - 5 inches (12 - 15 cm)
Type Locality: Tucurui, below dam, Rio Tocantins, Brazil
Comments: This infrequently imported species was once popular in North America in the early 1990s. It has largely been replaced in the hobby by the smaller and more colorful C. compressiceps, which is sympatric to this species in Rio Tocantins.
I briefly maintained this species during its heyday, and noticed that a lot of the wild caught specimen had a white parasitic worm crawling around its iris! It did not seem to visibly harm the fish, so I did not attempt to treat it.
The name cyclostoma refers to the round shape of its mouth, when looked from above. This character is in sharp contrast to the other members of its group and genus. This is not a particular aquarium resident, accepting most regular aquarium foods. It can be inferred from the shape of its mouth that it is not particularly piscivorous, unlike its relatives.
It inhabits rocky areas with strong to moderate water currents, so decorate its aquarium accordingly.
Described in: Beaufortia 36 (5); p 65