Probably Stolen Fish Farming Guide
How fish farming works in Probably Stolen, as the developer describes it — the Retired Aquafarmer upgrade in the Demo, the Aquafarmer starting scenario in 1.0, and the path from tilapia to sturgeon caviar.
Fish farming arrived in the Demo as the Retired Aquafarmer, a Wild’s Network upgrade: a retired merchant sells the equipment, and you begin with a basic water circulation system, a stock of tilapia and a supply of fish food. You keep the tanks healthy through water quality, filtration and the energy cell, breed fish from roe to fry to mature fish, move up from tilapia to eels and sturgeons, butcher fish with a knife for meat, and use Surgery Tools on sturgeons for caviar.
The developer calls it slower-paced, lower-maintenance and more beginner friendly than rat ranching. In 1.0, Aquafarmer is also a starting scenario.
Evidence level: Official Not site-tested Everything here comes from the developer’s 2026-10-19 Demo update announcement, plus the Aquafarmer line in the 2026-10-21 overview of 1.0. It describes what the developer says the system does; this site has not reproduced it in the Demo, and has not re-checked it in the 1.0 release. The animations in the announcement show updated UI coming in the full release, not the Demo UI. Sources last checked October 27, 2026.
How to start fish farming
There are two official routes in, and they belong to different builds.
| Route | Build | What you start with |
|---|---|---|
| Retired Aquafarmer Official | Demo, Wild’s Network upgrade added 2026-10-19 | A new retired merchant sells the equipment for raising fish in tanks. You begin with a basic water circulation system, a stock of tilapia and a supply of fish food. |
| Aquafarmer scenario Official | 1.0 starting scenario, per the 2026-10-21 overview | A stock of Tilapia and recirculating aquaculture systems. Water quality, fish food and environment affect what kind of fish you end up with. |
The 2026-10-19 Demo update adds fish farming to the Demo as a Wild’s Network upgrade; the 2026-10-21 overview lists Aquafarmer as a 1.0 starting scenario. How you unlock the Retired Aquafarmer and what the upgrade costs are not stated in the announcement.
Which fish you can farm
The developer describes a ladder: different varieties of tilapia first, then more valuable species, such as eels and sturgeons. Each species has its own habitat requirements.
| Fish | What the announcement says |
|---|---|
| Tilapia | Your starting stock. There are different varieties of tilapia. |
| Eels | Named as one of the more valuable species you expand into. |
| Sturgeons | Named as one of the more valuable species. Surgery Tools on a sturgeon harvest caviar. |
The 1.0 overview adds one more point for the Aquafarmer scenario: water quality, fish food and environment affect what kind of fish you end up with.
Keeping fish healthy: water quality, filtration and the energy cell
Because each species has its own habitat requirements, the announcement says you need to manage the tank’s water quality, filtration and energy cell to keep the tanks circulating and your fish healthy. You can also upgrade your fish tanks if you have the right materials.
The announcement does not give the requirement values for any species, or name the materials a tank upgrade needs.
How to breed fish
Breeding follows once a tank meets its conditions. In the developer’s order:
- Meet the species’ conditions — water quality, filtration and a running energy cell.
- The fish may then reproduce by laying and fertilizing roe.
- The eggs eventually hatch into swarms of fry.
- The fry grow into mature fish.
The word the announcement uses is may: meeting the conditions makes breeding possible rather than guaranteed. Hatch and growth times are not published.
Harvesting: meat, other resources and caviar
- Meat: use a knife to slaughter and butcher fish for their meat.
- Other resources: certain fish may also provide unique resources beyond meat. Which fish, and which resources, are not stated.
- Caviar: use Surgery Tools on sturgeons to harvest caviar.
The purpose, in the announcement’s words, is to raise fish in tanks to harvest and sell their meat. Sale prices for fish meat or caviar are not published, so this page does not estimate them.
Fish farming vs rat ranching
The 2026-10-19 Demo update compares aquaculture with rat ranching: it “is slower-paced, requires less maintenance and is more beginner friendly than Rat Ranching.” That comparison was about the Demo systems. Both are starting scenarios in the 1.0 line-up; the overview sums up Rat Wrangler only as “Can you grow a healthy 2x3 rat?”
What players report about rats — mousetraps, knife butchering and meat prices — is in the rats guide. The comparison above is the developer’s; this site has not played the two side by side.
What the announcement does not say
| Question | Current evidence |
|---|---|
| How do you unlock the Retired Aquafarmer? Unknown | It is a Wild’s Network upgrade in the Demo. Its unlock condition and cost are not stated. |
| Which tilapia varieties exist? Unknown | “Different varieties” is all the announcement says. |
| What does each species need? Unknown | Each has its own habitat requirements; none are listed. |
| What upgrades a tank? Unknown | “The right materials” — which ones, and what the upgrade changes, are not named. |
| What do fish and caviar sell for? Unknown | No sale price appears in either announcement. |
| Does the Demo match 1.0? Unknown | The Demo update describes the Demo; the 1.0 scenario is described in one line, and the full release ships an updated UI. |
Probably Stolen fish farming FAQ
How do you start fish farming in Probably Stolen?
In the Demo, through the Retired Aquafarmer, a Wild’s Network upgrade added on 2026-10-19. A new retired merchant sells the equipment for raising fish in tanks, and you begin with a basic water circulation system, a stock of tilapia and a supply of fish food. In 1.0 there is also an Aquafarmer starting scenario that opens with a stock of Tilapia and recirculating aquaculture systems. How the Demo upgrade is unlocked, and what it costs, is not stated.
What fish can you farm in Probably Stolen?
Tilapia first — the developer says there are different varieties of tilapia — before expanding into more valuable species such as eels and sturgeons. Each species has its own habitat requirements. The names of the tilapia varieties, and whether other species exist beyond the examples given, are not published.
How do you breed fish in Probably Stolen?
Meet the species’ conditions. Once the tank’s water quality, filtration and energy cell keep it circulating and the fish healthy, fish may reproduce by laying and fertilizing roe. The eggs eventually hatch into swarms of fry, which grow into mature fish. Breeding rates and growth times are not published.
How do you get caviar in Probably Stolen?
Use Surgery Tools on a sturgeon. That is how the developer’s Aquafarmer update describes it. Where to get Surgery Tools and what caviar sells for are not stated.
How do you get fish meat in Probably Stolen?
Use a knife to slaughter and butcher the fish. The developer adds that certain fish may also provide unique resources beyond meat, but does not say which fish or which resources.
Is fish farming easier than rat ranching in Probably Stolen?
The developer’s 2026-10-19 Demo update says aquaculture “is slower-paced, requires less maintenance and is more beginner friendly than Rat Ranching.” That comparison was made about the Demo systems, not about the 1.0 Aquafarmer and Rat Wrangler starting scenarios. This site has not compared the two in play.
Related pages
- Rats: traps, butchering and Rat Wrangler— the livestock line the developer compares fish farming against.
- Water: Moisture Farm and Water Merchant— the other water-based trade, and the earlier Retired Water Merchant upgrade.
- Money and buying the store— how any income line feeds rent and the 1.0 ending.
- All published guides— the current index.
Sources
- Demo Update - Aquafarmer — official announcement, 2026-10-19 — the source for the Retired Aquafarmer upgrade, the starting equipment, the species, water quality, filtration and energy cell, breeding, tank upgrades, butchering, caviar and the comparison with rat ranching
- Opening October 28: What's in Store for 1.0 Release? — official announcement, 2026-10-21 — the source for the Aquafarmer starting scenario in 1.0 and the Rat Wrangler line