They can be obtained by fishing in a Shoal or Tidal Pool with a Fishing Rod or rowing over it with Boats with an attached Trawl Net. Fish Farms that have been stocked with Roe have a chance to continually produce Tropical Fish.
Merms and Fishermerms will drop Tropical Fish when killed. Hammering down Merm Huts and Fishermerm's Huts will also yield Tropical Fish, however these structures are not renewable and destroying them will also remove the source of Merm and Fishermerms respectively. Fishermerms will fish in Tidal Pools on their own for Tropical Fish, but they will not eat what they catch, which then can then be collected by the player. Except for Fish Farms and Shoals, which are commonly found in Coral Reef and Mangrove biomes, all other sources of Tropical Fish can only be found in Tidal Marsh biomes.
Tropical Fish can be used in Crock Pot, and counts as 0.5 units Meats and 1 units of Fishes. Cooking Tropical Fish on a Fire will yield a Cooked Fish Morsel. It can also be dried to get Small Jerky. It can be traded to Yaarctopus for Dubloons.
- Tropical Fish has more meat and fish value than Cooked Fish Morsel obtained by cooking it on fire, so it is not recommended to cook Tropical Fishes if they are going to be used in the Crock Pot. Drying them also has a similar effect, but it may be more desirable since Small Jerky can be used in recipes that Tropical Fish cannot be, due to many Fish based recipes taking precedence over Meat based ones.
- Fish Farms that are stocking Tropical Fish are marked with a small sign showing a blue fish, after being harvested at least once.