Typhlonectes Natans FAQ

Typhlonectes Natans is a type of caecilian found in the aquarium trade in the US. They make good aquarium pets. T. Natans is the abbreviation. They are an amphibian from the Amazon tributaries and other rivers in South America. The whole species name is: Gymnophiona Typhlonectes Natans. The word Typhlonectes is used to refer to aquatic Caecilians from South America.

Will it hurt me?


It might try to bite if it is very hungry, but it can’t hurt a human. They might be irritating for us to eat, though, so wash your hands after handling them if you might touch food or your mouth. Don’t let your cats or dogs eat them.

They can carry some parasites that can be dangerous to other fish, but we don’t know of them carrying any diseases or parasites that can harm a mammal.

Where can I learn more?

Some zoos or public aquariums may have Typhlonectes or other caecilians on display.

There are several experts on the net who may answer questions on our message board. They know a lot more than we do.

Is it saltwater or fresh?

Freshwater exclusively. They won’t handle very much salt, even a little salt added to a tank (less than 1tps/gallon) will cause them trouble. It causes blisters on the skin.

Where are its gills?

They are an amphibian like a newt, salamander, or frog. Consequently, they breathe air from the surface of the water and do not have gills.

What gender is it?

This is hard to tell. If it gives birth, it’s female.

The important part is the “terminal region” (the butt). The white flat region under the end of their tail will contain either a “T” shape (some people think it looks more like a (“Y”) or a “Star” shape (*). The “T” butts may also have two or three visible dots on their terminal regions which are spaced around the “T” symmetrically. It appears that the “T” butts are female.

Male = *
Female = T or Y


Where can I get a Typhlonectes for my tank?
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They are no longer being exported from Brazil and Peru where they live naturally. Those countries are preserving their natural wildlife. If you want a Typhlonectes species aquatic caecilian you will have to do some calling around, searching, and advertising to find someone who is breeding them or has too many.

Check your local stores fist to see if they have any left. Then call farther away, as far as you are willing to drive to get one. Attend your local Aquarium Society meetings and ask if anyone has a Caecilian they don’t want anymore.

If you find someone who is willing to give or sell you an aquatic caecilian here is how to ship them :

Put the caecilians in a plastic container along with wet long-fiber sphagnum moss (or even crumpled-up damp paper towels) with a few very small air holes in the side. The plastic container may be packed in newspaper within a small styrofoam container (with a few small air holes) to protect them from major temperature changes. Keep in mind the temperatures where you are shipping. Cheapest way is Express Mail or, if you feel lucky, Priority Mail. Also, UPS usually works, but overnight service is $55 minimum and some local offices refuse to take live animals. Request that the box be left at the door even if no-one is home. Try to find a friend or relative who is home during the day and have them shipped to that address. Coordinate with your sender to make sure you know when the box will arrive.

Why won’t it eat?

It’s not hungry. Really, it’s not hungry. Might not be hungry for several weeks.

Sometimes (especially when they’ve just moved to a new tank), they go for a month or so without eating. Other times, they eat constantly.

They also might be eating something you can’t see (like bloodworms living in the gravel) or eating your fish and you haven’t noticed.

Just keep offering it a variety of food every few days until it eats. Don’t worry unless it stops moving.

What should I feed it?

They will eat almost anything, but most importantly, make sure the food sinks to the bottom. You can also hand feed your eels, if they aren’t shy, by holding the food near their nose. They are carnivorous.

  • earthworms
  • bloodworms (live, frozen, or freeze-dried)
  • tubifex worms (live, frozen, or freeze-dried) Stick the freeze-dried cubes near the bottom of the tank by pressing them onto the glass.
  • shrimp pellets
  • ground beef heart (can be frozen into cubes or flat sheets)
  • shrimp or fish meat (non-greasy)
  • algae wafers (occasionally, but it’s probably not a good staple diet for them)
  • slow-moving tank-mates

Are the fish starving it?

Unlikely, unless you have very large, fast, and aggressive fish. Fish will usually get a fair bit if the eels food, but the eels can be quite aggressive in protecting their food supply if they need to.

It is possible, though, that the caecilians aren’t getting as much of the food as you would like. In that case, change the form of the food to something the eels can get to easier or the fish have a harder time with. Tubifex cubes work well for that, either stuck to the side of the tank (the fish will nibble and the eels will gulp) or hand-fed (via fingers or a stick or something).

How big will it get?

Probably about 18 inches in a tank. In the wild, they can get over two feet, but you’re unlikely to see that. Try to keep them in a tank that is long enough for them to stretch out.

No matter how long they get, they shouldn’t get much wider then at the head unless they are pregnant or sick.

How often do they shed?

Usually no more than twice a month, but often less than that. The fish usually eat the skin quickly, so you shouldn’t worry about it.


Sexing and breeding.

Gender: The white flat region under the end of their tail will contain either a “T” shape (some people think it looks more like a (“Y”) or a “Star” shape (*). The “T” butts may also have two or three visible dots on their terminal regions which are spaced around the “T” symmetrically. It appears that the “T” butts are female.

Male = *
Female = T or Y

They are not very particular about mates. They will generally mate at certain times of the year but don’t seem to be choosy about the partner. We don’t know yet what times of year this happens.

They are born with adult organs, and are ready to breed immediately. They are most likely to pick someone close to their own size. More breeding seems to happen at certain times of year.

How will they breed?

The two opposite gender eels will twist together and spin through the water, trying to get their terminal regions (butts) to connect. The male’s terminal region will clasp onto the female’s and he will protrude his genitalia into the female and inseminate her.

How long until the birth?

About a year. 12 months. A long time. Some sources say 270 days. The mother eel will get really wide. We suspect that the mother can eject the young early if she is getting sick, or is under too much stress to carry them anymore. The young are juveniles, little adults with the ability to take care of themselves and breed.

How will the birthing happen?

The mother eel will swim around and around the tank pushing out a young eel every 20 minutes or so. A common litter is 2-6 young eels. Some of the young may be larger than others. The young eels will have white flaps of skin (looks like a cape) attached to it’s neck which will be pulled off by fish or rubbed off by decorations. This is normal.

How do I care for the young Typhlonectes?

If you suspect you have a pregnant female Typhlonectes, raise the temperature in the tank slowly to 84-88F. Keep the young at that temperature for 3-6 months after birth and then you can lower it to 78-84F for the rest of their lives. Note: Some fish (goldfish, rainbows) cannot tolerate temps over 78F. If the young get fungus infections raise the temp higher to 86-88F for a couple weeks. Temps that high are dangerous to many fish so we suggest you move the young eels to a hospital tank for that treatment.

Feed all the eels in the tank a varied diet; tubifex worms, blood worms, ground beef heart.

Clean the tank often and make sure you have adequate filtration for your new bio load.


What kind of water should go in the tank?

Standard Amazon river tank setup is the ideal.

Specifically: low pH (6.6), soft water, 78-86F, no salt. (But see the debate about salt that’s been ongoing on the discussion board… some salt may be OK as long as the specific gravity doesn’t change often)

It ate a fish, what should I do?

Eating a fish is not unhealthy for the eel. If you don’t want it to happen again, get larger or faster fish. The eels will hunt fish usually only when hungry, so maybe it needs more food.

My fish bites it, what should I do?

Move one of them to another tank, or take one of them back to the store. The eel will develop infections or fungus from the wounds and will eventually die. A temporary solution is to add a cave or tower in which the eel can hide.

It digs up my plants, what can I do?

The eel cannot be cured of this habit. Get plastic suction cup plants or get real plants that grow on drift wood or float.

Do they need to get out of the water?

Not really. They need to be able to get to the surface of the water to breath. If they get out of the water they have to be able to get back in. During migration season and sometimes while breeding or birthing they will try to get out, but don’t need to.


It got out of the tank, what should I do?

This is the most common fatality of pet eels. Put it in de-chlorinated water immediately, preferably in a hospital tank. If it was out for a long time it may develop blisters and scabs from drying out. Keep the water clean and moving and let the eel hide in a decoration. It may not eat for several weeks after this incident. The wounds may take months to heal, so keep fish from picking at them by keeping the eel in another tank or providing more hiding spots.

How do I keep it from getting out of the tank?

Use masking tape to seal every opening and flap on the top of the tank. You’ll have to re-apply the tape every month or so as it will get soggy and gummy. Another useful item is plastic craft grid canvas. It can be cut to the shape of the opening and then taped on. It can also be used to block the out spout of Power or ‘box’ filters without blocking the water flow. Our eels used to climb into the Power filter a lot until we blocked it.

What causes the blisters on the skin?

Usually, changes in water quality. Rapid changes in the pH, salinity, or ammonia/nitrogen levels are the usual causes of blisters and bubbles in the skin. Stress of moving and temperature changes are other causes. To prevent blisters, keep the water within tolerable ranges for the eels and change them slowly if need be. The blisters will go away very slowly and will get smaller with each shedding.

Is it eating too much?

Feed them as much as they will eat in 10 minutes once or twice a day.. Fatness is usually caused by pregnancy and not by overfeeding.

Why won’t it move?

Could be several reasons.

  • If you poke it and take it out of the water and it still doesn’t move, it’s dead.
  • If it has trouble moving, or moves slowly, make sure the temperature is high enough (78-84F).
  • If it never comes out from under it’s rock (or whatever) then it’s probably not hungry.
  • Switch foods or just wait. Poke it (gently) every week or so to make sure it isn’t dead.

What diseases can they get?

This is a hard question to answer, but we’ll go over the basic ailments and our limited understanding of the cures.

  • Blisters – To prevent blisters, keep the water within tolerable ranges for the eels and change the parameters (pH, salinity, ammonia, temp) slowly if need be. The blisters will go away very slowly and will get smaller with each shedding. Once the blisters rupture or tear, they are a likely place for fungus to grow. Often a 30% water change will be enough to cure the blisters.
  • Fungus – Appears as fuzzy white growths on the skin. Raise the temperature to 86-88F until the fungus goes away. Only use the high temperature treatment if your fish can handle it. An alternative treatment is medications like the ones found in aquarium stores. Get one for ‘fungal infections’ and follow the directions. We have no knowledge if the fungal medications are bad for eels.
  • Nematodes – Tiny worms that live inside the eel and borrow their way out through the skin. All eels have nematodes inside, but the nematodes only burrow out when the eel is unhealthy. Many eels are weakened by their transport to the pet store, and the stress of moving into your tank. Once the nematodes have decided to burrow out of the eel, there is little you can do, and the eel will most likely die. To prevent nematodes, keep your eel healthy. Monitor these factors; water quality, temperature, aggressive fish, and handling of the eel.
  • Floating – The eel floats at the top of the tank, and can’t seem to get down. This is usually caused by gas, and will go away in a couple days. If it persists, try changing the food. Add decorations or suction cup shelves if you want to give the eel something to cling to.
  • Bloating – The eel becomes puffed up in part or all of it’s body. Probably caused by something the eel ate. If you just tried a new food, stop using it. This happened to us once when our eel ate half of a live flower shrimp, including the shell. The eel then got the floating problem. It passed after 2 days.
  • Misc – No matter what the problem, never ever use an Ich or Ick treatment. It is highly fatal to eels. Don’t use medications that say “unsafe for invertebrates”. Eels are vertebrate, but they absorb chemicals through their skin in a similar way to snails and shrimps. Antibiotics seem to be safe, but we don’t know what the symptoms of a bacterial infection are. We have no knowledge if the fungal medications are bad for eels.

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