Jawless Fishtank Get the games

A cute little idle game where you raise your own Sacabambaspis, the real prehistoric jawless fish with the permanently shocked face. Feed them, grow them, name them, and try not to get too attached.

New game, out now on Android

Jawless Fish Races

Same fish, new job. In Jawless Fish Races your Sacabambaspis races three others, and the only way to swim faster is to answer questions. Math, spelling, clocks, coins, science and capitals, at three levels each. Made for kids, and sneakily good for homework.

Take a look

What you do

A fish tank that runs on real time

Jawless Fishtank is an idle pet game. You check in, feed your fish, scoop up some coins, and come back later. It's a nice thing to have running on a second monitor or to open on your phone while the coffee brews.

  • Hatch a few, raise them up

    Your first three fish are cheap, so grab a little school and go. Each one grows from baby to teen to adult to old over real days, not minutes.

  • Feed them, or else

    Hunger drops whether the game is open or not. Let it hit empty and health starts draining. Fish food is cheap. Guilt is not.

  • Weird food, big reactions

    Once you have some coins saved, try the good stuff. Chili, lemon, cherries, grapes. Fancier food builds affection faster, and some of it comes with a little kick.

  • Sell them or keep them forever

    A well loved adult sells for a lot of coins. Or you can see how long you can keep one alive. Both are valid. One is a lot harder once you name it.

Screenshots

Here's what it looks like

Swipe or scroll sideways for more. Tap one to see it full size.

The store

Six kinds of Sacabambaspis

Start with the classic grey and white one, then save up for Mossy, Autumn, Lover, Bluebaspis, or the Color Changer, which turns a different color depending on what you feed it.

See every fish and what it costs

Yes, it's a real fish

Meet the Sacabambaspis

Sacabambaspis janvieri swam in shallow seas around 460 million years ago, long before fish had jaws. It was first dug up in Bolivia, it was about the length of a ruler, and its eyes sat right at the front of its head, which is why every reconstruction looks like it just heard some gossip.

In 2023 a museum model of it went viral and it became one of the internet's favorite fossils. We think it deserved a nicer life than being a meme, so we gave it a fish tank.

Read more about the real Sacabambaspis

The Jawless Fishtank app icon, a white and grey Sacabambaspis on a slate blue background

Made with friends

From the folks behind the plushies

Jawless Fishtank was made by FiveFour Games together with Jawless Fish, who make the cutest Sacabambaspis plushies around. They asked if a game could work as a little love letter to the fish. It could. It launched on July 30, 2025.

More about who made it

Questions

Stuff people ask

What is Jawless Fishtank?
A small idle game where you raise a Sacabambaspis, a real fish that lived about 460 million years ago and has the most surprised face in the fossil record. You buy baby fish, feed them, watch them grow up, and decide whether to sell them or keep them forever.

Where can I play it?
On Steam for Windows and Linux, and on the App Store for iPhone and iPad, and on Google Play for Android. There's also a free demo on Steam if you want to try it first.

Is it on Android?
Yep, it's back on Google Play.

How much does it cost?
It's a few bucks. $2.99 on Steam and $0.99 on iPhone (US prices, and Steam runs sales). No ads and no in-app purchases. You pay once and that's it.

Do my fish keep growing when the game is closed?
Yes. Growth runs on real time, so a fish hatched today is a teen tomorrow. Hunger keeps dropping while you're away too, so don't leave them for a week. Coins pile up in the tip jar while you're gone, up to a limit.

Is it kid friendly?
Yep. It's rated 4+ on the App Store. No chat, no accounts, no ads, nothing online at all. Fish names go through a word filter too.

More answers on the support page.