What are Triops?
They are small freshwater shrimp that grow from tiny eggs that you can buy from most Pet or Toy shops. They
are often called Tadpole or Shield Shrimp.
Scientific name is Triops longicaudatus (TRY-OPS LON-GA-CAW-DA-TUS), by far the most common species you'll
find on sale in shops as they come from America. Triops cancriformis (TRY-OPS CAN-RIFF-FORM-IS) comes from Europe and
grows larger and lives longest!
Q: What do they do?
A: They swim alot, eat alot, grow even more and lay eggs. They're fun to watch with their antics as they swim cartwheels
looking for food. Some teachers even use them in the classroom to teach the science of life.
Other people use them as a
'beginners guide to raising fish' in an Aquarium. Because if you can look after a Triops for a few months then maybe you might
like to look after fish in a big tank!
Q: How do they breath under water?
A: They are very ancient creatures and long ago evolved the ability to breath with their feet! Fish have gills
in the sides of their head. Triops have their gills in their legs!
Q: Do they really have three eyes?
A: Yes, Triops have been around a long time and have evolved some strange things. One of their eyes sense light
so it knows which way is 'up'. Whilst the other two eyes look out for predators or snacks.
Q: How old are they?
A: Very old! In fact Triops (Triops cancriformis) have been around for over 220 million years. So they've
seen giant dinosaurs like Tyrannosaurus rex and Stegosaurus come and go.
They were swimming in pools when giant mammals like the wooly mammoth roamed the Earth.
When our ancestors lived in trees, there the Triops were in their pool, swimming and eating.
they are known as the oldest living species of animal in the World. No wonder they're often called or living fossils!
Q: Where do they come from?
A: Whilst toy shops sell them, they actually grow naturally in the wild on virtually every country in the World.
Scotland, Russia, USA, Africa, India, Iceland, Japan. You name it they are there!
Q: Are the eggs I buy taken from the wild?
A: All eggs you buy are collected from hand reared Triops in tanks and are not harvested from the wild. In some
countries (like the UK) Triops are actually an endangered species so taking them from the wild would be very wrong.
Q: Are they easy to rear in my home?
A: Yes, they are very easy to raise. You just need some eggs, a couple of litres (pints) of water and a container
of some kind.
You just add the water to the eggs, keep them at room temperature near a bright light source and watch them
See our Container page for ideas.
Q: What about feeding them?
A: Most kits you can buy in the shops come with plenty Triops food. But you can feed them virtually anything plant
related. See our Recipes page for some of the things Triops owners have thought up. You'll be surprised!
Q: Is it expensive to keep them?
A: Not at all. For around £4 pounds (US$7) you can buy the eggs. Then a glass or plastic container needn't cost
more than another £4 (US$7) if you wanted to splash out and get one specifically for raising Triops. You don't need to spend
more than another £2 (US$3.5) on bottled water. So for £10 (US$18) or less you've got a complete set up.
Of course you can spend more if you want to keep the Triops in the lap of luxury. Some people buy Aquarium tanks,
air filters and special food to ensure their Triops live the high life!
Q: How long do Triops live for?
A: If you keep them in good health then they can live as long as 14 weeks. Though 8 weeks is typical. (Triops
cancriformis lives the longest)
Q: Why so short a lifespan?
A: Because that's how they have evolved. In the wild they hatch out of their eggs within 24 hours of a pool of
rain water forming over them. They then eat and grow and eat again to grow as quickly as possible before the pool of water
evaporates. It's amazing watching how fast they grow. Within 7-10 days they're fully adult and can lay 10 eggs a day. They
continue to grow in size every day.
Q: How big can Triops get?
A: Triops can grow pretty big. Some Triops have been measured at 11cm (4inches) in the wild (we don't include their
long tails when measuring their length)!
Typically you can get them to grow 6-8cm (2-3inches) in length in a tank. Triops
cancriformis species grows the biggest. Triops owners like taking pictures of their wee creatures.
See the Gallery section of pictures and movies of their pets.
Q: Can a Triops bite me?
A: No. Their mouth is very small and there is no chance of it even nipping you in the slightest.
Q: Can I hatch out the eggs they lay?
A: Yes you can. You just drain off the water, let the eggs dry out really thoroughly for a few days and then add
some water again! You need never run out of eggs again!
Q: Are there different types of Triops?
A: Yes, quite a few.
Most commoningly sold in the shops is the American species called Triops longicaudatus
which looks rather golden in colour. It grows up to 8cm (2 inches) and lives for up to 8 weeks.
Then there is the Triops cancriformis species which is found throughout Europe and can grow up to 11cm (4
inches) and lives for longer (14 weeks) than its American cousin and is more green-brown.
There is an Australian species called Triops australiensis which is rarely seen outside its country and
is more copper-blue in colour.
What is 'detritus'?
This is the name used in biology for organic waste material from decomposing dead plants. Typically dried
up leafs, etc.
What is detritus used for?
When Triops hatch out they require very small food to eat, the detritus contains micro-organisms which
hatch out when added to water. The Triops larva need this to survive the first 3 days. Later they need to eat bigger food
that you provide, like the brown and green pellets provided by some kits.
What is this water conditioner bag I've got?
Some Triops kits supply a 'tea bag' like package of detritus. It's only there to provide food to hatch out
the young Triops. Once your Triops are more than 3-4 days old You can remove it. But don't throw it away. Let it dry out in
a warm spot and you can reuse it if you plan to hatch out further Triops at a later date.
So after 3 days I can remove the bits of detritus?
Yes. Some Triops kits come with the detritus contained in bags, so you can simply dry it out and use it again.
Loose detritus can be thrown away. If you ever need more collect a dried leaf from out side and tear it up.
What is infusoria?
This is the correct name for the micro-organisms which grow out of the detritus.
Why do they need constant light in the first 72 hours?
One, the eggs are triggered to hatch out if they get wet and have a strong light source on
them. No light, no hatching.
Two, when the infusoria hatches out from the detritus they gather at the light source. This
is usually the water surface in nature. So we need a light above the water. When the Triops hatch out, they move towards the
surface and can therefore eat the infusoria which they expect to find there.
If the Triops don't get enough to eat in the first 3 days, they quickly starve to death.
A simple Mains table lamp with a 40W-60W bulb a few inches above the water is all that is required.
My Triops Kit say don't add anything into the tank. Why?
They say this so that you'll have more success in hatching out the Triops.
Triops like water with low mineral content in order to trigger them to hatch out. By adding things to the water
like sand, plants, ornaments. Then you could possibly reintroduce minerals or chemical to the water which will cause the Triops
eggs not to hatch.
I find using a substrate like coral sand that has been very well rinsed in a bucket is fine. Just ensure you never
use soap or any detergent in any of the tank items. You'll kill the Triops.
None of my Triops hatched out. Why?
This is always one of the following reasons.
a) You didn't provide pure enough water. Triops eggs need very pure water to trigger them into hatching. Bottled
water can have too much minerals in it. Look for the 'Dry Residue' amount on the label. If it is more than 90mg, get a purer
source of water. Distilled or de-ionised water is perfect.
b) You didn't have a source of light above the water on constantly for the first 72 hours then they will not hatch.
The Triops eggs need light to trigger them into hatching.
c) You didn't have the water temperature at around 22°C (±5, If it is too hot or too cold, then the Triops eggs
will not hatch.
Some of my Triops hatch out and within a day or so they all died! Why?
This is usually due to the following reason.
You may have used too much water. The more water you have
in the tank, the more the infusoria is diluted and so the tiny Triops have difficulty finding enough to eat in the crucial
first 72 hours. So they simply die from lack of food.
I recommend that you only have about 5cm of water column. In a standard
Triops 1 litre kit this is usually about half full. You can add the rest of the water once they're over 3 days old.
Why didn't they all hatch out?
Triops are very clever, their eggs are designed not to all hatch out at once.
This saves them all from
dying if for example the pool gets filled by just a passing shower and would only last a week or less. If they had all hatched
out, they'd all die. But by staggering their hatching they maximise their survival. One reason why Triops have survived over
200 Million years.
Why do I need to use pure water?
See the question 'None of my Triops hatched out'
You don't need pure water but you will get more Triops hatching if you do.
Triops in the wild come from temporary
pools of rain water, so they have developed a special survival technique.
A pool of rain water may dry out at any time, so to ensure that Triops hatch out in optimal conditions, the egg
senses the amount of minerals dissolved in the water. The less minerals the fresher the water must be. A large pool of water
will also stay fresher for longer than a small puddle for example.