The cave tetra is a freshwater fish that is perfect for beginner aquarium hobbyists. These fish are peaceful, easy to care for, and make a great addition to any community tank.
This guide will teach you everything you need to know about cave tetra care. You’ll learn about their diet, tank mates, size, lifespan, and more!
Table of contents
Species overview
The cave tetra (scientific name: Astyanax mexicanus) is a freshwater fish that’s found in various parts of Mexico, as well as some areas of Texas and New Mexico.
They prefer to live in dark, murky waters with very little light and a lot of hiding places. This is something to keep in mind when setting up their aquarium.
Cave tetras are omnivores, which means they’ll eat both plants and small animals. In the wild, their diet consists of things like insects, crustaceans, and small mollusks.
These fish are very popular in the aquarium trade because of their unique appearance. They have long, slender bodies and their eyes are set far back on their head, which gives them a “blind” look.
Appearance
The cave tetra is a small, peaceful freshwater fish that is grayish-brown in color. They have a dark stripe that runs along their side, starting at their snout and running all the way to their tail. This dark stripe is what earned them the name “cave tetra”.
The cave tetra is a small fish, only growing to be about 2 inches in length. They have a slender body shape that is common among tetra species.
The fins on the cave tetra are all relatively small. The dorsal fin is the largest of the bunch and starts about halfway back on the body. The other fins (pectoral, anal, and caudal) are all short and stubby.
The cave tetra is a schooling fish, so they do best when kept in groups of 6 or more. They are peaceful fish that get along well with other peaceful species.
Lifespan
The lifespan of a cave tetra in captivity is 5 to 8 years. This is a relatively long lifespan for a freshwater fish.
However, it’s worth noting that their lifespan in the wild is much shorter. In the wild, these fish only live for 2 to 3 years.
The main reason for the difference is that captive cave tetras don’t have to worry about predators or other dangers. They also have a much more stable food supply.
Size
The cave tetra (Astyanax mexicanus) is a small freshwater fish that only grows to be about 2.5 inches in length.
Tank
Tank Size
The minimum tank size for a school of cave tetras is 30 gallons. If you want to keep a single fish, you can get away with a 20 gallon tank but we don’t recommend it.
These fish are very active and do best in a school so we recommend a tank on the larger side if you’re looking to keep them.
Water Parameters
The cave tetra is a tropical species that does best in warm, slightly acidic water. These fish are not as tolerant of changes in water parameters as some other species, so it’s important to keep a close eye on things.
Here are the ideal water parameters for cave tetras:
- Water Temperature: 72 to 82 degrees Fahrenheit
- pH Levels: 6.5 to 7.5
- Water Hardness: 2 to 12 dGH
- Alkalinity Levels: 4-8 dKH
What To Put In Their Tank
When it comes to setting up the inside of an aquarium for cave tetras you can be as creative as you want. There aren’t any specific things that this species NEEDS to have, which gives you plenty of options.
We recommend some of the standard decorations that you find in a lot of freshwater tanks. There are a ton of great plants you can include (like hornwort or water wisteria). You can even throw in some floating aquarium plants too!
Rocks, driftwood, and caves are all suitable as well. It’s important to avoid going overboard with this since these fish like some room to swim.
Also, if you’re keeping your cave tetras in a smaller tank then it’s going to be difficult to include a lot of this stuff anyway.
A classic gravel substrate is always a good choice, but you can do with something soft and sandy if needed too (use other species you keep as a guide with this).
Common Diseases
The cave tetra is a freshwater species of fish that is relatively hardy and resistant to disease. However, that doesn’t mean that they’re immune to all illnesses.
The most common disease that affects this species is ich. This is a parasite that can quickly take over a fish’s body and cause serious health problems.
The most obvious sign of ich is the presence of white spots on the body, fins, and gills of your fish. If you see this, it’s important to take action immediately.
There are a number of other diseases that can affect the cave tetra, but they’re not as common. Some of these include fungal infections, bacterial infections, and parasites.
As with any other fish, the best way to keep your cave tetra healthy is to maintain a clean and stable aquarium. This will create an environment that is less conducive to disease and will help your fish stay healthy.
Behavior & Temperament
The cave tetra is a peaceful fish that does well in a community tank. It is shy and peaceful, and it will not bother other fish.
The cave tetra is a nocturnal fish, so it is most active at night. During the day, it will hide in caves or other dark places in the tank.
The cave tetra is a schooling fish, so it should be kept in groups of at least six. The fish will feel more comfortable and less stressed in a group, and it will be more likely to come out and be active.
The cave tetra is not an aggressive fish, but it is territorial. It will defend its territory against other fish, so it is best to keep only one cave tetra per tank.
The cave tetra is a peaceful fish that does well in a community tank. It is shy and peaceful, and it will not bother other fish.
The cave tetra is a nocturnal fish, so it is most active at night. During the day, it will hide in caves or other dark places in the tank.
The cave tetra is a schooling fish, so it should be kept in groups of at least six. The fish will feel more comfortable and less stressed in a group, and it will be more likely to come out and be active.
The cave tetra is not an aggressive fish, but it is territorial. It will defend its territory against other fish, so it is best to keep only one cave tetra per tank.
Tank Mates
Because cave tetras come from slow-moving waters in the wild, they do best with tank mates that prefer similar conditions.
These fish are also on the smaller side, which means that they can easily become prey for larger, more aggressive species.
For these reasons, it’s important to choose tank mates that are compatible in size and temperament.
Here are some examples of good tank mates for cave tetras:
- Neon Tetras
- Cardinal Tetras
- Ember Tetras
- Ghost Shrimp
- Guppies
- Mollies
- Platies
- Swordsplants
- White Cloud Mountain Minnows
Breeding
Cave tetras are not the easiest fish to breed. They are very sensitive to changes in their environment and need specific conditions to spawn.
The first thing you need to do is set up a breeding tank. It should be at least 20 gallons and have a sandy bottom. Add some caves or hidey-holes for the fish to feel secure.
The water should be soft with a pH of 6.5. The temperature should be around 77 degrees Fahrenheit.
When ready, add two males and two females to the tank. The males will have longer fins and a more slender body shape.
Cave tetras are egg-layers. The female will lay her eggs in a cave or among the plants. After she lays them, the male will fertilize them.
The eggs will hatch in about 24 hours. The fry will be very small and need infusoria to survive. You can culture your own or buy it from a pet store.
As they grow, you can start adding baby brine shrimp and other small live foods. Once they’re big enough, you can move them to your main tank.
Conclusion
The cave tetra is a great fish for beginner aquarists. They’re not too difficult to care for and they’re very peaceful, which makes them a good addition to community tanks.
They’re also a very unique fish, which is always a bonus.
If you’re looking for a fish that’s a little bit different and you’re not afraid of a little bit of a challenge, then the cave tetra is a great choice for you!
