The Fish Index is the most overlooked progression system in My Fishing Brainrots. Most players rush rebirths and ignore it. That's a mistake.
Fish Index bonuses are permanent cash multipliers that survive rebirth and stack with everything else. A player with 100% Fish Index completion earns double cash forever. Combined with rebirth bonuses, high-level players hit 6x multipliers while new players wonder why they're stuck.
Fish Index Milestone Rewards
Every milestone gives a permanent cash bonus that never goes away.
| Fish Types | Reward | Total Bonus |
|---|---|---|
| 10 | +10% cash | 10% |
| 25 | +15% cash | 25% |
| 50 | +25% cash | 50% |
| 75 | +25% cash | 75% |
| 100 | +25% cash | 100% |
At 100 fish types, you earn double cash on everything. This stacks multiplicatively with rebirth bonuses.
How Fish Index Works
Your brainrots catch fish automatically. Each unique fish type gets registered in your index permanently. You never lose progress, even after rebirth.
You can't target specific fish. Instead, you influence what fish appear by:
- Brainrot rarity (higher rarity = rarer fish)
- Fishing Luck upgrades (affects all brainrots)
- Brainrot diversity (different brainrots catch different fish pools)
Fish Rarity Tiers
Fish have their own rarity system separate from brainrots.
| Fish Rarity | Required Brainrot | How Hard |
|---|---|---|
| Common | Any | Automatic |
| Uncommon | Any | Easy |
| Rare | Rare+ | Moderate |
| Epic | Epic+ | Takes time |
| Legendary | Legendary+ | Rare catches |
| Mythic | Mythic | Grind territory |
If you're missing high-tier fish, the problem is usually brainrot rarity, not bad luck. You need Legendary brainrots to catch Legendary fish consistently.
How Multipliers Stack
Fish Index bonuses multiply with rebirth bonuses. This is where the real scaling happens.
| Setup | Total Multiplier |
|---|---|
| No index, no rebirth | 1x |
| 50% index, no rebirth | 1.5x |
| No index, 3 rebirths | 2x |
| 50% index, 3 rebirths | 3x |
| 100% index, 5 rebirths | 6x |
A player with full Fish Index and 5 rebirths earns 6x what a fresh player earns from identical brainrots. This is why late-game players seem to print money.
Filling Your Index Faster
Diversity Over Power
Running only your strongest brainrots is a trap. Different brainrots catch different fish pools. If your base is full of identical Legendaries, you keep catching the same fish repeatedly.
A mixed setup fills the index faster than a min-maxed one.
Keep One of Each Type
When you hatch a new brainrot, keep it even if it seems weak. That random Rare might catch a fish your Legendary can't. You can replace Commons later. Early diversity matters more than raw income.
Upgrade Fishing Luck First
Fishing Luck upgrades affect all brainrots at once. This is the single biggest accelerator for rare fish entries. Prioritize it over individual brainrot upgrades in early game.
Watch for Time-Based Fish
Some fish only appear under specific conditions. If your index is stuck at 47 or 73, check which fish are missing. You might be playing at the wrong time or missing event-exclusive fish.
Progression by Phase
Early Game (0-25 Fish)
This happens naturally. Just play. Common and Uncommon fish fill in automatically. You'll hit 25 fish types within the first few hours without trying.
Mid Game (25-50 Fish)
Rare fish start mattering. You need Rare+ brainrots to progress. This is where most players slow down because they sold all their Rares for cash.
Keep at least one of each brainrot type you hatch.
Late Game (50-75 Fish)
Legendary fish appear. You need Legendary brainrots, and they need to be upgraded. Patience matters here. Some fish just take time to show up.
Endgame (75-100 Fish)
The real grind. Mythic fish require Mythic brainrots. Event-exclusive fish might be blocking completion. Missing seasonal events can delay full completion for months.
Fish Index and Rebirth
Fish Index progress is permanent. When you rebirth:
- Fish Index stays at 100%
- All milestone bonuses remain active
- You keep earning the multiplier immediately
This means rebirthing early without filling your index slows long-term progress. The bonuses you miss out on compound over time.
Pre-Rebirth Checklist
Before hitting that rebirth button:
- Check how close you are to the next milestone
- If you're at 48 fish, wait for 50 (+25% permanent bonus)
- If you're at 73 fish, consider pushing to 75
Never rebirth at 48 fish types. That 50 milestone is too valuable to skip.
Common Mistakes
Selling diverse brainrots for cash - That Rare you sold might have caught a fish your Legendaries can't. Keep variety.
Ignoring Fishing Luck upgrades - This affects all brainrots. It's more efficient than upgrading individuals early on.
Rushing rebirths at 48 or 73 fish - The next milestone is right there. Wait.
Running identical brainrots - Same brainrot type = same fish pool. Mix it up.
Missing seasonal events - Event fish count toward your index. Some only appear during specific events.
Event Fish
Seasonal events introduce exclusive fish that count toward your index. Missing them can permanently slow completion unless they return.
Check the game's Discord and Roblox page for event schedules. Admin Abuse events are especially valuable because Disco mutations also help with rare fish catches.
FAQ
Does Fish Index reset on rebirth? No. Fish Index progress is permanent. You keep all bonuses forever.
What's the fastest way to fill the index? Diversity. Run different brainrot types, upgrade Fishing Luck, and don't skip events.
I'm stuck at 47 fish. What's wrong? You probably need higher rarity brainrots. Check which fish are missing and what rarity they require.
Should I rebirth before completing milestones? No. Always hit nearby milestones first. The bonuses are permanent and stack with rebirth bonuses.
Do event fish count toward the index? Yes. Event-exclusive fish are part of the 100 total.
Related Content
- My Fishing Brainrots Guide - Full beginner guide
- My Fishing Brainrots Rebirth Guide - When and how to rebirth
- My Fishing Brainrots Tier List - All brainrots ranked
- My Fishing Brainrots Codes - Free rewards
