Max Size: 4cm

Mountain Crystal Tetra (Protocheirodon pi, leptagoniates pi)

Mountain Crystal Tetras are very peaceful and active fish; however, they are pretty shy and have a nervous disposition. Despite this, these fish will settle down relatively quickly in the right aquarium with the right conditions. These Tetras are hardy and undemanding fish that add a unique look to the nano or planted aquarium.

Mountain Crystal Tetras are a schooling fish; therefore, it would be better to keep Mountain Crystal Tetras in a large group of at least ten individuals as they will feel more comfortable, will be less skittish and will display more natural behaviour.

Mountain Crystal Tetras can be housed in a community aquarium, providing you keep them with suitable tankmates. Ideal tankmates should be of a similar size and temperament. These can include small surface-dwelling species such as Hatchetfish and other smaller Tetras, as well as peaceful bottom dwellers such as Corydoras and Whiptail Catfish. However, it would be best if you did not house these fish with aggressive or predatory tankmates, and it is advisable that you have these Tetras as the only mid-water species.

Mountain Crystal Tetras will do best in a blackwater biotope setup with plenty of decors so the fish can establish their own territories. Also, make sure you provide plenty of shade in the form of plants so that this species does not feel too exposed.

Mountain Crystal Tetras have a transparent body that displays tiny black dots on it, and these spots also cover the anal and dorsal fins. These fish also have a black mark on their caudal peduncle. Their swim bladder is parted in two and has a connection on the top, thus forming a figure that reminds one of the ancient Greek letter Pi hence the name.


Mountain Crystal Tetra
Mountain Crystal Tetra
Mountain Crystal Tetra
Mountain Crystal Tetra
Quick Facts
Scientific NameProtocheirodon pi, leptagoniates pi
Other NamesPi Tetra
Aquarium LevelMiddle
DifficultyBeginner - Intermediate
Best kept asGroups 10+
Lifespan3 - 5 years
Water Parameters
Water TypeFreshwater
PH6.0 - 7.5
GH5 - 20
76 - 82℉
24.4 - 27.8℃

Natural Habitat

Ucayali River


In the home aquarium, the Mountain Crystal 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 very challenging to determine the males from the female Mountain Crystal Tetras as they are practically identical in appearance. However, sexually mature females will more than likely be fuller-bodied than males when they are carrying eggs, and because of their transparent bodies, you will probably be able to see the eggs.

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: 01/09/2021 15:36:28 - Updated: 02/12/2021 17:28:12