The Sturgeon is a fish that can be caught in the Mountain Lake during Summer and Winter. It is most common on rainy summer days and least common on rainy winter days, which are only possible with a Rain Totem. Casting at least 3 tiles from shore increases the chance of hooking one. It can also be caught on the Wilderness Farm during Summer and Winter. With Magic Bait, it can be caught regardless of season or time of day.
Sturgeon may also be gifted by a pet cat with max friendship, and it can appear in Krobus' shop on Wednesdays or in the Traveling Cart. Like other fish, it can be placed in a Fish Pond, where it reproduces every 4 days. The pond starts with a capacity of 1 fish and can be expanded to 10 by completing four quests. The only possible pond output is Sturgeon Roe, which can be processed in a Preserves Jar to make Caviar.
When raising Sturgeon in a Fish Pond, the quest items needed to increase capacity are 1 Diamond, then 1 Jelly, 2 Maple Syrup, or 1 Pickles, then 3 Omni Geodes, and finally 1 Nautilus Shell. Each quest grants 40 Fishing XP. The pond's production becomes more valuable as population increases: at higher capacities, Sturgeon Roe becomes much more likely, and at a full pond the chance of producing nothing drops to zero only at population 10 for one of the production outcomes.
Sturgeon is also useful outside of fishing. It can be used in the Sewing Machine to create the Fishing Vest, and it can be used as a blue dye in the dye pots at Emily and Haley's house. Because it is one of the fish needed for Caviar production, keeping a Sturgeon pond is a reliable way to generate a steady supply of Roe for processing.
Best fishing conditions: rainy summer days in the Mountain Lake
Fishing tip: cast at least 3 tiles from shore
Special bait: Magic Bait ignores season and time restrictions
Fish Pond output: only Sturgeon Roe, which can become Caviar
