Triops – Bizarre But A Great Tank Addition

Last updated: September 28, 2022

Post by: CompletePondCare on August 28, 2005, 05:11:11 PM
If you’re looking for a tank trashman that’s more interesting to watch than ghost shrimp, easier to maintain as live food than brine shrimp or blood worms, when offered as live food for fish will stay alive in the community tank until it’s either eaten or has grown too large to be eaten, and never fails to get a shocked reaction of, “What the #&%@! IS that thing?!” from people who’ve never seen one before, look no further than the hardy and hardworking Triops.

Triops © CompletePondCare

I just LOVE my Triops! It’s a tank cleaner that truly eats detritus—not mostly algae, like most other so-called detritus-eaters; this guy is like an aquatic earthworm—, leaves your fish alone, never seems to stop moving, isn’t very picky about water conditions, and reproduces so easily and copiously that it’s a snap to keep a culture of hatchlings going for live fish food.

The Triops is a freshwater crustacean that’s survived completely unchanged since the Triassic era. It’s built a lot like a tiny horseshoe crab, with a hard shell on top, WAY too many legs underneath, and grasping claws at the front. Like some killifish and lungfish, it relies on ‘diapause’ for reproduction, making it very easy to hatch out from dry eggs. Its life span is short, only about 40 days on average, and it typically grows no larger than about 2″—though there’s one monster on record that made it to 3″. The one in the photo above is about 1 3/4″ long. Here’s another pic, with an adult, female Endler’s Livebearer at the right to give some idea of scale:

Triops with a female Endler © CompletePondCare

Triops eggs are hatched in a small container of spring water (I use Aquafina bottled water) seeded with a small amount of tank or pond detritus, to make the water a little acidic and to provide microscopic food for the hatchlings. Since they don’t require filtration or aeration, and do fine from room temperature up into the 80’s, you can keep your culture in an old spaghetti sauce jar on the kitchen counter—just keep it out of direct sun. If you’re hatching out large numbers to use as live fish food you’ll want a bigger ‘tank’, but you still don’t need filtration or aeration. The eggs hatch overnight into tiny, daphnia-sized nymphs. They can be fed on detritus as they grow, or with the pelleted food you get with a Triops starter kit. Mine seem to grow out just fine on nothing but small, weekly additions of pond muck to their tank. If you go the pond muck route, do be careful that there aren’t other carnivorous critters in the muck large enough to eat your Triops.

From the day they hatch, Triops double in size and molt every day until they reach sexual maturity, at about 10 days old and 1- 1.5″ inches long. They continue to grow after that, just not as quickly. Triops are cannibalistic, so even if you’re not netting them out to feed to your fish you’ll notice their numbers decreasing as they grow into adulthood. At that point they’re too big to be eaten by my Endler’s and Killies, so I like to keep 1 – 3 adult Triops in each of my fish tanks to live out the rest of their short lives as tank janitors. Despite having three eyes they’re practically blind, and since I’m putting them into the tanks at roughly the same size, cannibalism is no longer a problem. They have plenty to eat in the tanks anyway between detritus and fish food, and there’s nothing quite as comical as the sight of a Triops that’s happened onto a blood worm and is trying to wrestle it into submission. I swear, it’s like watching a puppy rolling around on its back with a chew toy!

Sexually mature female and hermaphrodite Triops drop about 300 eggs a day—each! Eggs are tiny but are easily harvested by simply allowing the tank to dry out completely after the last adult dies, using a dry paintbrush to gently loosen the egg-laden, dried detritus, and then pouring the dried egg/detritus mixture into a jar for up to 15 years of storage. Storing the eggs in the dried detritus in which they were originally deposited makes creating new cultures of Triops as easy as dumping a spoonful of your dried culture into a new jar of spring water.

You have to buy your first batch of Triops eggs, but the kits are inexpensive and easy to find online and in education-supply stores. The kits include a ‘teabag’ of dried detritus (which can be dried out and re-used over and over, since it gets re-seeded each time you use it) and food, which are both needed if you haven’t got access to a pond. Once you’ve got your first crop of adults, future egg supplies should never be a problem.

Here’s a website with lots more excellent Triops info, including a simple and foolproof approach to egg harvesting & storage: (

Title: Re:Bizarre But Great Tank Addition
Post by: Mellyn on August 29, 2005, 09:24:01 AM
I tried hatching my triops but they all died on about the third day. They were in distilled water and hatched all right. I had about 7. At first I had the light on for 24 hours. I turned it off at night. Then I noticed the little bugs weren’t moving anymore. Any suggestions to what I did wrong or what to do next time? I think they might have gotten cold since they were in the living room.

Title: Re:Bizarre But Great Tank Addition
Post by: CompletePondCare on August 29, 2005, 02:06:37 PM
You do need to keep the temps between 72 – 84F for hatching, but once they reach sexual maturity they seem able to tolerate a wider range.

Title: Re:Bizarre But Great Tank Addition
Post by: SerVo on August 29, 2005, 05:26:41 PM
Well i don’t think it would have been water related or they wouldn’t of hatched. Most likely they starved to death due to no protazoa/ microscopic life in the water (ditrius packtes add this to it). If the ditrius got moisture in it, it is enough to reek havoc on the microscopic life, but the eggs untouched.

Title: Re:Bizarre But Great Tank Addition
Post by: CompletePondCare on August 29, 2005, 10:07:30 PM
SerVo – I don’t understand what you’re saying about the detritus getting wet…the detritus ‘teabag’ gets soaked when you put it in the Triops hatching tank, and if you’re supposed to leave it in the tank for the first 7 days if you’re using that form of detritus.

I’ve found several blogs from Triops enthusiasts who claim to have successfully used that detritus ‘teabag’ over and over, drying it out in between uses, so even if the bag were exposed to moisture while stored in the kit, unless it stayed wet I’d think it’d still be OK. Is your experience different?

Title: Re:Bizarre But Great Tank Addition
Post by: magickzzl on September 06, 2005, 05:49:23 PM
Aww.. I miss my triops…. maybe I’ll try them again.

Title: Re:Bizarre But Great Tank Addition
Post by: Mellyn on September 07, 2005, 09:44:40 AM
I got another batch of eggs. I don’t think they starved b/c I put a drop or two of infusioria in there when I saw a few had hatched. I think they must have gotten cold.

How much light do they need? For the next batch I was planning on putting them on top of my mini fridge in my room. It is nice and warm. They’ll be next to a window with a curtain that lets in about 50% of the sunlight. Would this be suitable? Will they need light for the first 24 hours? (I read that somewhere)

Title: Re:Bizarre But Great Tank Addition
Post by: CompletePondCare on September 07, 2005, 03:16:13 PM
I hatch mine on the kitchen countertop, beneath a Spacesaver radio/CD player that has a light underneath it. They get some light, but not a lot. It sounds like your location will be OK, so long as the water doesn’t get hotter than 84F. I’ve had a couple of attempts that failed too, so don’t give up yet. Good luck!