The pond mechanics
A fish pond (built at the Carpenter’s Shop) holds one species — up to 10-12 fish per pond population. Fish produce roe every few days (value scales with the fish’s base price), and periodic population quests ask for a specific item (an item per fish added). Fulfill the quest, population grows, roe output rises.
The standouts
Sturgeon roe becomes caviar (the premium jar product) — the classic pond pick. Lava Eel roe sells high and the pond occasionally produces magma stone... spicy items; Super Cucumber ponds roll rare iridium-adjacent drops; Blobfish produce high-value roe plus random goodies. Rainbow trout occasionally drops a Prism Shard... a rainbow-shell prize that keeps the pond surprising.
Ponds versus fields
A pond’s daily value is lower than a maxed crop field per tile, but it costs zero labor after setup, works all winter, and fits odd corners of the farm. A row of ponds (one species each) is the winter income plan that pairs with the artisan shed.