Biotoecus opercularis

The Biotoecus opercularis is a peaceful dwarf cichlid that comes into its own in a species aquarium

Biotoecus opercularis

Biotoecus opercularis can reach a length of about 7 centimeters. When young they have a dull gray color. Once mature, they do not have the bright colors of some other cichlid species, but display a variety of iridescent colors on their bodies, ranging from violet/purple to yellow/green. Adults have a grayish base color with an iridescent violet/purple on the flank. In females, this color is more pronounced, especially around the belly region, as is the yellow/green on the gill cover. In the males, a row of metallic green spots stands out along the flank. Both males and females have a dark spot on the gill cover (this is what the name opercularis refers to). They also have 5 dark spots in their dorsal fin and a dark spot in the middle of the flank that is visible depending on the mood.


Rio Negro, Rio Jauaperi, Santarèm, Blackwater Amazon, Brazil.

The Aquarium

An aquarium of at least 80 centimeters is required for the Biotoecus opercularis. Furnish the tank with dense vegetation, driftwood, and stones so that sufficient caves and hiding places are created. The bottom should consist of fine sand.


Temperature: 27-29 degrees Celsius. pH: 6-6.5 GH: 3-6


Small live food should be given as food such as daphnia, brine shrimp, cyclops, black and white mosquito. If the food is too big for the younger fish, you can scrape it down to make it smaller.


The Biotoecus opercularis is a peaceful dwarf cichlid that is best kept as a harem in a special aquarium. The females each have a small territory within the large territory of the male.

Breeding Biotoecus opercularis

Breeding Biotoecus opercularis is quite simple, about 100 eggs are laid and fertilized in a cave. The female cares for and guards the clutch, and the male defends the territory. After 3 days the eggs hatch, and 4 days later the young swim around freely. The fry can be reared with brine shrimp nauplii.




Copyright images

F. Ingemann Hansen – Ben Lee –

Bijgewerkt op 23 April 2023 door John

Additional information





First described by


Social behaviour

Breeding behaviour


Min. aquarium length in cm





, ,

Minimum length

Length maximum

Temperature minimum
Temperature maximum

pH minimum

pH maximum

GH minimum

GH max


There are no reviews yet.

Be the first to review “Biotoecus opercularis”

Your email address will not be published. Required fields are marked *