Max Size: 12cm

Mexican Tetra (Astyanax mexicanus)

The Mexican Tetra is Hardy and peaceful and is an excellent choice for the beginner aquarist and suitable for most community aquariums, however slow of very timid tankmates are best-avoided. It occasionally nips at tankmates when feeding, but its searching technique causes this rather than aggression.

Although you cant describe this Tetra as sociable, it doesn't appear to fare any better when maintained in a group.

The Mexican Tetra has the usual characin shaped body and has undistinguished, drab colouration. It gets its name because it has no eyes or pigment. Its body is pinkish-white with silver linings on their body resembling that of an albino.

Even though these fish are blind, they can still, however, find their way around utilizing their lateral lines which are highly receptive to fluctuating water pressure.


Mexican Tetra
Mexican Tetra
Mexican Tetra
Mexican Tetra
Mexican Tetra
Mexican Tetra
Mexican Tetras
Quick Facts
Scientific NameAstyanax mexicanus
Other NamesBlind Cave Fish, Blind Cave Characin, Blind Cave Tetra
OriginsMexico, USA
Aquarium LevelMiddle
DifficultyBeginner - Intermediate
Lifespan3 - 5 years
Water Parameters
Water TypeFreshwater
PH6.5 - 8.0
GH5 - 30
TDS90 - 447
68 - 77℉
20 - 25℃


In the home aquarium, the Mexican Tetra will readily accept most good quality dried foods such as granules, flakes and sinking pellets. These modern food products have been developed to provide all adequate nutrition to maintain your fish's health and dietary requirements.

Providing additional foodstuffs such as live, frozen, and freeze-dried meals such as bloodworm, daphnia, and tubifex once or twice a week will provide additional benefits to your fish's health and well-being but is not a must for this fish.

It should be noted that bloodworms should only be given as an occasional treat and should not be used as the staple diet as they are difficult for fish to digest and can potentially cause blockages.

This fish is an omnivore in the wild, meaning it will consume some vegetable matter. Although most modern fish foods take this into account and include them in their products, you can still supplement your fish's diet with blanched vegetables such as spinach, broccoli, and zucchini. Ensure you do not overfeed your fish and remove any leftovers the following day.

Sexual Dimorphism

It is quite tricky to distinguish males from females; however, typically the anal fin of the male has a slightly curved edge, while the females tend to be straight and when in spawning the females are somewhat more extensive than the males.

Other Tetras of interest

Adonis Tetra(Lepidarchus adonis)
African Moon Tetra(Bathyaethiops caudomaculatus)
African Red Eyed Tetra(Arnoldichthys spilopterus)
Arowana Tetra(Gnathocharax steindachneri)
Black Darter Tetra(Poecilocharax weitzmani)
Black Line Tetra(Hyphessobrycon scholzei)
View all Tetras
Date Added: 16/10/2020 - Updated: 02/12/2021 17:27:10