Monday,26 July 2021, 3 : 33 PM

Aequidens tetramerus

Aequidens tetramerus
Image Credit: wikipedia


Aequidens tetramerus is a somewhat large size fish of about 6.5 " found in Amazon and Orinoco River basin.


(Click for details of Cichlid taxonomy)

Aequidens tetramerus was first described by Heckel in 1840 and was described as Acara tetramerus.
Over the years it was given other names and is now placed in Genus Aequidens and subfamily Cichlasomatinae.
The Genus "Aequidens" is derived from Latin words, aequus+equal+dens(teeth), which roughly translates to "Fish with equal teeth".


Aequidens tetramerus is one of the larger fish in its genus with standard length of 6.5 ".
It has a typical tri serial pre dorsal arrangement of scales of genus Aequidens with E1 scales 25 or 26.
It is known to live for 8-10 years.

Distribution & Habitat

Aequidens tetramerus is widely distributed and is found in Amazon River basin,in Peru, Colombia, Ecuador, Brazil and Bolivia.
They are also found in the Tocantins and Parnaíba rivers, French Guiana, Suriname, Guyana, and in the Orinoco River basin of Venezuela and Colombia.
It is benthopelagic or swims above river/stream bed at depths of about 1-3 m in black water rivers.

Keeping in Aquarium

Tank Size and setup:

Aequidens tetramerus are somewhat large sized fish and should be kept in a aquarium of about 300 liters with good filtration.
A sand bed of fine sand and many shelters with rocks and driftwood are ideal for this fish.
They are mildly aggressive towards other species but can be highly aggressive to others of same species.
At breeding time the aggression increases.
Small fish should not be kept with them as it will be eaten.


Aequidens tetramerus are dimorphic, and reach sexual maturity in about 9-11 months.
They lay eggs on flat surfaces and practice brood care.
Both parents take care of eggs and larvae.
The females are smaller and will clean a piece of flat rock and lay 1000 eggs.
The eggs will hatch after 2-3 days and fry will be free swimming within a week.
Fry can be fed brine shrimp.
The pair will be ready to breed again if the fry are removed early.

Species Snapshot

Species Card

Particulars Details
Scientific Name Aequidens tetramerus
Common Name Saddle Cichlid
Genus Aequidens
Subfamily Cichlasomatinae
Geographical Origin widely distributed in the Amazon River basin in Peru, Colombia, Ecuador, Brazil and Bolivia.
Diet omnivore
Gender Differences Dimorphic
Breeding Substrate Spawner
Temperament Mildly aggressive
Con Specific Temperament Highly aggressive
Water hardness Medium Soft, dh range 1-13
Difficulty Level in Aquariums 3

Morphometric Data

Particulars Details
Total Length(inches)
Standard Length(inches)

Measurements as % of Total Length

Particulars Details
Body Depth  %
Head length  %
Pre Dorsal length  %
Pre Pectoral length  %
Pre Anal length  %
Pre Pelvic length  %
Caudal Peduncle Depth  %
Caudal Peduncle Length  %
Fork length  %
Length of Last Dorsal Fin Spine  %
Pectoral Fin Length  %
Pelvic Fin Length  %

Measurements as % of Head Length

Particulars Details
Head Width  %
Snout length  %
Eye diameter  %
Pre Orbital Length  %
Inter Orbital Width  %
Pre Orbital Depth  %

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