Triops are prehistoric creatures with an interesting growth pattern, captivating appearance, and a phenomenal approach to survival.
They look like miniature horseshoe crabs or tadpoles with shields, and that’s why Triops are sometimes referred to as Tadpole shrimp or Shield shrimp.
This species will make an excellent pet for kids due to its low maintenance and also, they will have the opportunity to learn a thing or two about a Triop’s lifecycle.
Keep reading for everything there is to know about Triops, this includes its biology, hatching tips, and how to care for the critter in a freshwater tank.
Quick Notes about Triops
| Name | Triops |
| Other Names | Tadpole shrimp, Shield shrimp, Longtail tadpole shrimp, Rice tadpole shrimp, Triassic Triops, or Dinosaur shrimp |
| Scientific Name | Triops cancriformis and Triops longicaudatus |
| Tank size (optimal) | 5gallons (~20 liters) |
| Keeping | Easy |
| Breeding | Easy |
| Size | up to 2 – 3 inches (5 – 7 cm) |
| Optimal Temperature | 72 – 86 °F (22 – 30 °C) |
| Optimal PH | 7.0 – 9.0 |
| Optimal GH | 1 – 10 |
| Nitrate | Less than 40 ppm |
| Diet | Detritivore |
| Predatory | Yes (small organism) |
| Life span | 60 – 90 days |
| Color Form | Reddish-pink to brown |
Origin
Triops is a genus of small crustaceans in the order Notostraca. The genus contains some freshwater species that are considered living fossils, with a record that dates back to the late Carboniferous period, over 300 million years ago.
The name Triops is of Greek origin, tria meaning “three” and ops meaning “eye”, in reference to the three eyes of this prehistoric critter.
Notably, Franz Von Paula Schrank, a German priest, botanist, and entomologist was the first author to use the genus name Triops, as seen in his 1803 work on the fauna of Bavaria.
The genus Triops consists of over 10 species, however, most of them are considered to be more ‘exotic’ species among hobbyists.
In the aquarium trade, Triops cancriformis and Triops longicaudatus are the most popular and the most common Triops species.
The scientific classification of Triops is as follows:
Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Crustecea
Class: Branchiopoda
Order: Notostraca
Family: Triopsidae
Genus: Triops
Habitat
Triops has a cosmopolitan distribution; the small freshwater crustacean is widespread across Africa, Asia, South America, North America, Australia, Europe, and the Pacific Islands.
They often inhabit rice fields, rain pools, ponds, swamps, and other freshwater, temporary waterbodies.
Such habitats tend to experience inundation from rainfall, followed by desiccation from evapotranspiration.
Description
Depending on the species, these creatures are typically between 0.5 to 4 inches (1 – 10 cm) in size.
| Species | Average Size in Captivity | Color |
| Triops longicaudatus | 1 – 4 cm (0.4 – 1.5 inches) | Reddish, brown, or grayish-yellow color |
| Triops cancriformis | 6 – 7 cm (2.4 – 2.8 inches) | Translucent carapace. With time it becomes more opaque |
Triops are characterized by the presence of a pair of dorsal compound eyes and a third eye— naupliar ocellus between the two eyes.
Interesting fact: The third eye can only distinguish light from the darkness.
They possess a broad, shield-like carapace at the upper part of their body which is followed by a long, slender abdomen bearing two elongated appendages. This appearance is similar to that of tadpoles, hence the common name “tadpole shrimp”.
The body of this invert is segmented into a head, thorax, and abdomen; while the head bears a pair of dorsal compound eyes and two pairs of antennae, the anterior thorax comprises 11 segments, each bearing a pair of appendages called thoracopods or pereiopods. And the posterior thorax has about 16 – 25 segments that are partially separated to form rings.
In addition, each ring consists of as many as 6 fused segments and bears up to 6 pairs of appendages. These appendages are involved in executing bodily functions such as sensory, feeding, locomotion, and respiration.
From the ventral side, Triops have numerous legs (up to 70 pairs), which is not observed in any other crustaceans.
Lifespan
The natural lifespan of Triops is relatively short, with species living for just 50 – 90 days or even lesser depending on the conditions (water parameters and food availability) of their habitat.
Lifecycle of Triops
The lifecycle of Triops begins with newly hatched Triops that are tiny and orange-colored, and these hatchlings develop through instars — each instar ending with a molt i.e. shedding of the exoskeleton.
The instars or growth stages are continuous till the Triops are mature — usually in about one or two weeks after hatching, and thus, able to breed and lay eggs.
Additionally, Triops eggs will remain in a state of diapause during long periods of drought that often leads to desiccation of the vernal pools. And when the pool becomes filled with rainwater the Triops eggs will hatch successfully and progression continues.
Behavior
Triops are extremely fun crustaceans to watch because they are constantly moving in search of food.
In spite of the fact that in nature they are often found in big numbers, Triops are not social animals.
As they get bigger, Triops become more predatory and even cannibalistic.
Features:
- Social: No
- Active: Yes
- Peaceful: Yes (when young)
Feeding Triops
Triops are omnivores, and as such, they can feed on animal and plant matter as well as commercial fish food.
There are countless options when it comes to ideal food for this invertebrate, these include:
- daphnia,
- tubifex worms,
- grindal worms,
- bloodworms,
- detritus worms.
- fruit flies,
- copepods,
- brine shrimp,
- fish fry,
- insect larvae (mosquito larvae preferably),
- fresh veggies (boiled carrots, romaine lettuce, peas, potatoes, etc.).
Interesting fact: Sometimes Triops are used in the biological control of mosquitoes.
In addition to high-quality food, for example (links to check the price on Amazon):
That’s not all, Triops may sometimes eat their shed skins, plus the foliage of aquarium plants (like Elodea, Marimo moss ball, etc.), algae, detritus, biofilm, and organic debris in the aquarium.
They should be fed adequate portions at least twice daily, and leftovers should be removed at the end of the day to prevent them from rotting and ruining the tank water.
Making sure that your Tadpole shrimps get enough food to eat will help reduce the rate of cannibalism to the bare minimum.
Interesting fact: If there is no enough food Triops can even use their thoracic appendages to filter food.
Note: According to the study, as Triops grow, their diet preference also changes and they become more predatory. Field and laboratory observations showed that the number of animal prey was significantly higher in big-sized animals than in small-sized animals.
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Features:
- Diet Type: Omnivore
- Food Preference: Detritus and small organisms
- Feeding Frequency: 1 – 2 times a day
Triops and Live Plants
It is not recommended to keep Triops in tanks with expensive plants.
These creatures are voracious eaters. When they are hungry, they will eat any organic they can find. Soft leaves and roots are under direct danger.
So, unless you have fast-growing plants or plants that you are ready to lose, do not keep Triops in planted tanks.
Tank Requirements and Water Conditions
Tank size:
A 5 gallon (20 L) fish tank can be used to house about 5 – 7 Triops, such that each adult Triops gets 2 – 4 liters (1/2 – 1 gallon) of water for optimal population density.
Water parameters:
Temperature: The ideal temperature for keeping Triops is within the range of 72 – 86 °F (22 – 30 °C). At temperatures above 34 °C (93 °F) most species of Triops will die off. Additionally, the hatching of Triops eggs is greatly affected when the water temperature exceeds the recommended range.
pH: Tadpole shrimp is extremely hardy. They will tolerate a pH range of 6.0 – 10.0. However, the optimal pH range for the critter remains 7.0 – 9.0.
Hardness: Triops can live in any type of water. However, for the best results, it would be better to keep them in soft to moderate water to thrive and breed successfully in the aquarium.
Lighting:
Adult Triops doesn’t require high or intense lighting conditions to survive in captivity.
That said, they will remain healthy and thrive under low – moderate illumination from any artificial lighting source, so you may use normal fluorescent aquarium lights or LED lighting.
Note that, lighting is essential in a breeding tank because the eggs are able to detect light and dark conditions. Thus, the hatching rate is increased when favorable conditions including lighting and optimal temperature are present.
Substrate:
Since Triops are benthic dwellers, it would be nice to have a considerable amount of substrate (about 2 – 3 inches or 5 – 7 cm) on the aquarium floor to encourage their innate digging habits in the search for edibles.
Moreover, having a substantial portion of the substrate in the tank promotes chances of recovering viable eggs since a lot will be buried away from the reach of the adult Triops.
Ideal substrate options are coral sand, aquarium gravel, small soft pebbles, and aquarium sand.
Nonetheless, personally, I would recommend sand as the most suitable substrate for keeping Triops as it supports easier digging, ensures less water cloudiness, and buffers the pH to the right levels.
Filtration:
Rearing tank. You do not need filtration in breeding tanks. It is not safe for baby Triops. After hatching they are so small that will be easily sucked in even if you use an extra pre-filter in the form of a sponge.
Display tank. Once again, you do not need to have one. However, in this case, you will have to do frequent water changes.
If you want to have minimum maintenance, it would be better to use some form of filtration. Generally, there are no special requirements. As long as you have got the filter that works great with the size of the tank you have got you will be fine.
Personally, I would always recommend using sponge filters for any small Triops tank. These filters are cheap, easy to maintain, and clean; they provide a lot of surfaces to graze on.
Keeping and Caring for Triops
Triops is a hardy and undemanding freshwater invertebrate, thus caring for it is relatively easy.
Here, you need to ensure that the tank water they live in is of excellent quality — by performing partial water changes every few days or at least a week (if you do not have filtration). Simply remove one-quarter (25%) of the tank water and replace it with fresh, dechlorinated water.
This helps keep the aquarium clean, replaces depleted elements, and equally removes excess nitrates from the tank water which could harm the Tadpole shrimps if allowed to accumulate further.
Important: Do not use tap water without aging it first for a day or two (Chlorine will usually evaporate out of water within 24 hours). It can harm their gills or even kill Triops.
Make sure to keep a close eye on the Triops eggs. And as soon as they hatch, transfer the baby Triops to a separate tank to avoid predation by the adult Triops. Move them back to the main tank when they attain a considerable size (around 1 inch or 2 – 3 cm).
Also, test the tank water weekly, and make sure that the water parameters (temperature, pH, etc.) are at the ideal values; this activity is highly important if you want your Trips to remain in good health condition.
Triops may be tolerant of a wide range of water values, but they don’t handle rapid fluctuations quite well.
Lastly, maintain a good and consistent feeding schedule, and remember to acclimate Triops hatched in a different tank/container to the main tank’s conditions before moving them.
Breeding and Hatching of Triops Eggs
Generally, Triops reproduce through several methods.
One of them is sexually when both males and females are present in a given Triops population. They will mate; the male inseminates the female, and in turn, she will lay batches of fertilized, desiccation-resistant eggs.
Also, some populations of Triops may consist of hermaphroditic individuals that are capable of selfing.
Another method is through parthenogenesis, which is a form of reproduction in which an egg develops into embryo without being fertilized. Thus, female Triops can be able to reproduce without having to mate with a mature male.
Generally, eggs are released in batches that can vary from 10 to 100 in number.
Interesting fact: Females can modify their eggs according to environmental conditions. When they are not favorable, they lay the eggs with thick capsules which can stay in dormancy until conditions improve.
In a dry state, they can withstand an increase in temperature of up to 80 °C (176 °F). They can pass through the frog’s or bird’s intestines. They are easily carried by the wind, and, apparently, even over very long distances. Due to these qualities, Triops are widespread throughout the world.
Triops Eggs Set up
Now, let’s look at how to hatch Triops eggs successfully in a captive freshwater environment.
- First, you need to acquire viable, dried Triops eggs from a local fish store or through online aquarium stores. These are often sold in kits, and a kit contains dried eggs buried in coral sand, a plastic tank, plus food and care instructions.
- Get a clean, small plastic or glass container and fill it with a few inches of freshwater.
Note: I repeat – small and shallow containers (like containers from Triops kits)! You only need to have water 2 – 3 inches deep (5 – 7 cm). Do not use your main tank for that. The point is that baby Triops will have problems finding food that is diluted in large water volumes. It will reduce their survival rate. - Make use of spring water, rainwater, or tap water treated with a commercially available dechlorinating agent or water conditioner for this process.
- Next, make a small layer of sand in the container, then add the Triops eggs and a little bit of powdered food.
- Additionally, avoid direct sunlight exposure, and keep the eggs warm under a lamp to stimulate hatching.
Typically, the eggs should hatch within 48 – 96 hours under optimal conditions. 2 days after hatching you can start feeding them adequately.
Feeding Baby Triops
Serve the hatchlings crushed fish food or spirulina powder until the 8th day. At this juncture, the Triops are now ready to be transferred to the main tank, but first, make sure to acclimate them to the conditions of the new tank to avoid shock when introduced fully.
You may now switch to uncrushed fish flakes/pellets, making sure to feed them twice daily.
Also, it’s a good idea to supplement their diet with protein and veggies from the second week.
In addition, Triops tend to bury a lot of eggs in the sand, so these eggs can be extracted from the substrate, dried out and stored for later use. Not to worry, the Triops eggs will remain viable for many years.
For example, Triops longicaudatus eggs may remain in a state of diapause for up to 20 years.
Under optimal conditions, Triops grow very fast, starting from a near-microscopic form to almost doubling in size every day until they attain peak (adult) sizes.
Watching these little creatures grow that quick within a short period is truly marveling.
Problems Associated with Triops – Eggs don’t hatch
This is probably the most common problem when people are trying to keep Triops. There can be many reasons for that:
- The defense mechanism of evolution. According to the study, even under optimal conditions, not all eggs hatch in a given hydroperiod, some remain dormant until future hydroperiods so spreading the reproductive risk over time.
- Bad or ‘wrong’ eggs. Some Triops kits do not have enough Triops eggs. Instead, most of the eggs are eggs of fairy shrimp, daphnia, etc.
- Light. The Triops eggs require light to trigger them into hatching. Therefore, during the hatching period, you need to have a very long light cycle. Ideally, it should be on for 24 hours.
- Too low or too high temperature. Water temperature greatly affected the egg hatch. To hatch Triops eggs, the temperature should be in the range of 22 – 27 C (72 – 80 F).
- Too much minerals. This is another survival tool that Triops have been using for millions of years. The reason behind it is simple. In nature, Triops are found in pools of water that can dry out at any time. When it happens the amount of minerals dissolved in the water increases in the water. Basically, it is a sign that this pool will not be suitable for living in the nearby future. The eggs can detect it. So, the less minerals the fresher and the better the water must be.
Buying Triops and Triops Kits
A special note should be made about Triops kits which often include some small containers.
They are sold as a system that does not require any maintenance. Well, this is not true in so many ways!
- Triops grow really fast. Adult animals require at least 1 liter (1/4 gallon), optimally, 4 liters (around 1 gallon). Otherwise, they may become aggressive and start cannibalizing.
- Small containers will get dirty very fast.
- In addition, in small tanks, everything can go wrong really fast. Unfortunately, sudden fluctuation in water parameters can kill the colony.
Personally, I do not encourage anybody to buy these kits. They are essentially death traps for the Triops in the long run.
You can use these kits only for hatching eggs. Afterward, Triops should be moved to a bigger tank.
Triops and Suitable Tankmates
Even though Triops are highly opportunistic, they are not active hunters unless they are completely starving.
Therefore, technically, it is possible to keep them in a peaceful community tank.
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Fish
Concerning the fish species and some natural enemies, Triops should not be kept with big or aggressive fish like Botia lohacata, Cichlids, Loaches, and Goldfish.
Their tankmates should include other calm and peaceful community tank fish (for example, Panda Garra, Pygmy Cory Catfish, Otocinclus Catfish, etc.).
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Dwarf Shrimp
In nature, Triops and dwarf shrimp are not generally natural cohabitants. Nonetheless, it is possible to keep them in the same tank. Triops will not touch healthy shrimp.
However, sick, injured, or recently molted shrimp can be eaten.
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Freshwater snails
Freshwater snails can be great companions for Triops. The only problem can be with very small snails. Once they have something that fits between their mandibles they will not let it go.
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Crayfish and Crabs
There should not be a lot of problems with dwarf crayfish species (like Cambarellus Diminutus, Cambarellus pure, etc.) and small freshwater crabs (like Pom Pom Crab or Thai Micro Crab). These species are too small to overpower Triops even if they want to.
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Dwarf Frogs
Adult Triops will be safe to keep with a Dwarf frog; they are too big enough to swallow. Small Triops will be eaten.
African Dwarf Frogs can and will try to eat anything that fits their mouth.
In Conclusion
Triops are among the many species that can serve as beginner aquatic pets. Hatching and raising Triops in a freshwater tank is very easy, hence you should consider getting a kit for yourself.
There are several varieties of Triops in the market, however, I recommend the albino forms of Triops longicaudatus and Triops cancriformis because of their stunning look. The albino variant has a translucent carapace which will become more opaque as it grows, and they appear reddish-pink.
Despite their short lifespan, Tadpole shrimps are fascinating creatures; they grow extremely fast, breed easily and they will readily gobble down any kind of food.