Mutations in Fisch change two things about a catch. They alter how the fish looks during the reeling stage, and they multiply its sell value. With more than 150 variants in circulation, the question most players care about is simple. Which mutation pays the most, and how do you actually land it?
Quick answer: Aether is the highest-value mutation in Fisch at a 12× sell multiplier, ahead of Fury (11.7×) and Hades' Curse (11.1×). Because it sits at the top of the priority order, a fish that rolls Aether keeps it instead of a lower-value mutation.

Highest-value mutations in Fisch (12× and below)
Mutations are ranked from highest to lowest sell multiplier. The ones near the top are the rarest and most valuable, and they win out when several mutations compete for the same fish.
| Mutation | Sell multiplier | Type | Priority |
|---|---|---|---|
| Aether | 12× | Mutation | 1 |
| Fury | 11.7× | Limited | 0 |
| Hades' Curse | 11.1× | Mutation | 2 |
| Golden Part | 11× | Limited | 2 |
| Cosmos | 10.85× | Limited | 0 |
| Departed | 10.5× | Limited | 0 |
| Ocean's Ruin | 10.2× | Mutation | 0 |
| Plagued | 10× | Mutation | 0 |
| Tryhard | 10× | Mutation | 0 |
| Olympian | 10× | Mutation | 0 |
| Ascended | 9.9× | Mutation | 1 |
| Gravitas | 9.81× | Mutation | 0 |
| Requies | 9.8× | Mutation | 2 |
| Astraeus | 9.6× | Limited | 0 |
| Fabulous | 9.6× | Mutation | 0 |
Aether's 12× value is the ceiling for standard mutations. Everything below it trades raw multiplier for slightly easier access, though the top dozen all sit firmly in endgame territory.
How mutation priority and replacement work
The priority system decides which mutation a fish keeps when more than one could apply. Two rules drive it.
First, a higher multiplier outranks a lower one. If a fish could roll both a strong and a weak mutation, the stronger value takes the slot.
Second, there is the combined-chance rule. When the total chance for all eligible mutations on a cast goes over 100%, the game trims the lowest-multiplier mutations down to a 0% chance to make room. The exception is the Priority stat. A mutation with a higher Priority number resists being squeezed out even if its multiplier is lower, which is why something like Hades' Curse (priority 2) can hold its place against larger fields.

Attributes that stack on top of a mutation
Attributes are separate from mutations and can stack with each other and alongside a mutation. This is the real path to record sell values, because a combination like a Shiny Sparkling Glitched fish multiplies the base several times before the mutation multiplier is even applied.
| Attribute | Multiplier | Base chance | Notes |
|---|---|---|---|
| Shiny / Sparkling | 1.85× | 1% | No risk of loss during appraisal |
| Glitched | 0× | 100% on duped fish | Only via Glitched Potions |
Several rods and effects raise the odds of Shiny. The Glimmering Crown adds +10%, the Blessed effect adds +5%, and Rainbow weather adds +5%. Rod passives also contribute, including the Destiny Rod (+10%), the Paintbrush (+10%), and Pinion's Aria (+14.2%, rising to 22% with Mastery Enhancement). These are additive boosts on the base 1% chance.
Note the difference with size attributes. Tags such as Tiny, Small, Big, and Giant only describe how far a fish's weight deviates from its base. They do not change sell value, and they can be lost during appraisal if the weight shifts back toward the normal range.

How to get and increase mutations
There are two main routes to a mutated fish. You can catch one naturally, or you can apply a mutation through Appraisal.
Step 1: Fish normally and watch the reeling stage. A mutation shows up immediately as a visual effect on the fish, so you can tell before selling whether a catch carries one.
Step 2: Use gear and conditions that boost mutation odds. Certain fishing rods, specific weather, limited-time events, and admin events carry exclusive mutations and raise the chance of catching mutated fish.
Step 3: Take fish to the Appraiser to roll a mutation onto them. The Appraiser's Luck gamepass increases the chance of obtaining mutations this way, and it lets you keep re-rolling toward a higher-value result.

How to confirm a fish's mutation and value
You will know a mutation applied in two places. During reeling, the fish displays its mutation effect, such as a glowing aura or a recolored body. When you inspect or sell the catch, the listed value reflects the multiplier, so a 12× Aether fish sells for twelve times the base price before any stacked attributes are counted.
If you expected a mutation and did not get one, the usual reasons are straightforward. The natural mutation roll simply did not hit, the lower-value mutation you wanted was trimmed to 0% by the combined-chance rule, or the event, weather, or rod that grants a specific mutation was not active at the time of the cast.
For most players chasing the single biggest payday, Aether remains the target to beat. Pair it with Shiny and Sparkling, land it on a high base-value fish, and one catch can outsell an entire ordinary inventory.