Monkey Bay and Nkudzi Bay, Lake Nyasa (Lake Malawi).
Biotope:
Genyochromis mento is a very common mbuna and the only Malawi cichlid known
to occur in all habitats of Lake Malawi except the open water column, and
at all locations around the lake. In rocky habitats it adopts a darker
coloration to blend in with the rocks while hunting, whereas in sandy
habitats it takes on a sandy-silvery coloration.
Coloration can change depending on the habitat in which the fish is actively
hunting.
Geographic distribution:
Lake-wide distribution throughout Lake Malawi, occurring at numerous
localities around the lake without clear geographic variation.
Typical adult size:
In the lake, males reach up to about 13 cm total length, while females
remain slightly smaller, up to approximately 11 cm.
Too few specimens have been maintained in aquaria to confirm any difference
in maximum size under captive conditions.
Sexual dimorphism:
Males and females are indistinguishable in coloration.
During spawning the female appears to be consistently smaller than the male.
Recommended aquarium size:
If maintained in captivity, the species must be kept strictly by itself.
A very large aquarium would be required, but no established standards
exist due to its rarity in aquaristics.
Aquarium setup:
Genyochromis mento is rarely exported for the aquarium hobby and local
collectors normally never mix it with other cichlids.
In an aquarium it must be kept alone, as it starts attacking tank mates
almost immediately after introduction.
The species is robust and tolerates some fluctuation in water chemistry,
but recommended conditions are a pH between 7.0 and 8.5 and a constant
temperature between 23 and 28 °C.
Diet:
A carnivorous mbuna specialized as a fin-biter and occasional scale-eater.
Genyochromis mento ambushes passing fishes and removes pieces of fins or,
less frequently, scales, showing little species preference among its
victims.
Breeding:
Maternal mouth-brooder.
Males do not hold breeding territories due to their fin-biting behavior.
Courtship and spawning occur at any suitable location in the rocky habitat,
and mouth-brooding females are rarely observed.
Aggression:
Extremely aggressive toward other species, as its feeding strategy involves
biting fins of other fishes.
In captivity it has been observed to attack conspecifics as well.
Special notes:
Genyochromis mento is effectively absent from the aquarium hobby due to its
predatory fin-biting behavior.
If kept in captivity it must be housed alone.
In Lake Malawi it is one of the most common cichlids, though never found
in large numbers, and it is not considered threatened.
Photo gallery