The Fish Index is the most underrated system in My Fishing Brainrots. Most players ignore it completely. Big mistake. Those permanent cash multipliers are the difference between grinding for hours and breezing through content.
I’m at 73 fish types collected. The 50% permanent bonus changed everything. This My Fishing Brainrots Fish Index guide covers how to fill yours fast.
What is the Fish Index?
The Fish Index tracks every unique fish type your brainrots have caught. Each new fish gets logged permanently. Complete milestones unlock permanent cash multipliers.
Key word: permanent. These bonuses survive rebirth. They stack with rebirth multipliers. They’re the foundation of long-term progression.
Fish Index Rewards
| Fish Types | Reward | Cumulative Bonus |
|---|---|---|
| 10 | +10% cash | 10% |
| 25 | +15% cash | 25% |
| 50 | +25% cash | 50% |
| 75 | +25% cash | 75% |
| 100 | +25% cash | 100% |
That 100% bonus means you’re earning double what a player with 0% earns. Forever. Through every rebirth. It’s massive.
How Fish Are Caught
Your brainrots catch fish automatically based on:
- Brainrot rarity - Higher rarity = rarer fish
- Brainrot level - Upgraded brainrots catch better fish
- Fishing luck upgrades - Global bonus to fish quality
- Time - Some fish only appear at certain times
You don’t control which fish get caught. Your brainrots just fish and whatever they catch gets logged.
Fish Rarity Tiers
Fish have their own rarity system:
| Fish Rarity | Caught By | Index Value |
|---|---|---|
| Common | Any brainrot | Easy to get |
| Uncommon | Any brainrot | Fairly common |
| Rare | Rare+ brainrots | Takes time |
| Epic | Epic+ brainrots | Harder to get |
| Legendary | Legendary+ brainrots | Rare catches |
| Mythic | Mythic brainrots | Very rare |
Common brainrots can only catch Common and Uncommon fish. If you want Legendary fish in your index, you need Legendary brainrots.
Filling Your Index Fast
Here’s how to maximize Fish Index progress:
Diversity Over Power
For index completion, you want diverse brainrots, not just your strongest ones.
Different brainrot types catch different fish. A base full of identical Legendaries might be strong, but they’ll catch the same fish repeatedly. Mix it up.
Keep One of Each Type
When you hatch a new brainrot type, keep it even if the rarity is low. That Rare Skibidi might catch fish your Legendary Bombardiro can’t.
Obviously replace Commons eventually. But during index grinding, variety matters.
Upgrade Fishing Luck
The global Fishing Luck upgrade increases rare fish chances for ALL brainrots. This is huge for index completion.
Priority order for index grinding:
- Fishing Luck upgrades
- Diverse brainrot collection
- Individual brainrot upgrades
Time-Based Fish
Some fish only appear during certain conditions:
- Night fish - Only caught at night (in-game time)
- Day fish - Only caught during day
- Event fish - Special event periods
- Weather fish - During specific weather
Check your index for fish you’re missing. If they’re time-based, you might need to play at different times.
Index Completion Strategy
Phase 1: Easy Catches (0-25 fish)
Just play normally. Common and Uncommon fish fill in automatically. You’ll hit 25 fish types within the first few hours without trying.
Focus on:
- Filling brainrot slots
- Basic upgrades
- Learning the game
Phase 2: Rare Hunting (25-50 fish)
Now you need Rare+ brainrots. Common brainrots won’t cut it anymore.
Focus on:
- Hatching Rare and Epic brainrots
- Keeping diverse brainrot types
- Upgrading Fishing Luck
Phase 3: The Grind (50-75 fish)
Epic and Legendary fish start appearing. These are harder to catch.
Focus on:
- Multiple Legendary brainrots
- Max Fishing Luck upgrades
- Playing at different times for time-based fish
Phase 4: Completion (75-100 fish)
The final stretch. Mythic fish and rare variants.
Focus on:
- Mythic brainrots (required for some fish)
- Event participation (event-exclusive fish)
- Patience (some fish are just rare)
Fish Index and Rebirth
Here’s the beautiful part. Fish Index progress is permanent.
When you rebirth:
- Your brainrots are deleted
- Your cash is reset
- Your Fish Index stays exactly the same
This means you should prioritize Fish Index completion BEFORE rebirthing. Every fish you catch pre-rebirth is progress you keep forever.
Pre-Rebirth Index Strategy
Before each rebirth:
- Check your Fish Index for gaps
- Hatch diverse brainrots to fill gaps
- Let them fish for a while
- Then rebirth
Don’t rush rebirth if you’re close to an index milestone. That 25% bonus is worth an extra hour of fishing.
Stacking Multipliers
Fish Index bonuses multiply with rebirth bonuses:
| Scenario | Total Multiplier |
|---|---|
| 0% Index, 0 Rebirth | 1x |
| 50% Index, 0 Rebirth | 1.5x |
| 0% Index, 3 Rebirth | 2x |
| 50% Index, 3 Rebirth | 3x |
| 100% Index, 5 Rebirth | 6x |
A player with maxed Fish Index and multiple rebirths earns 6x what a new player earns. That’s why both systems matter.
Common Index Mistakes
Ignoring It Completely
The biggest mistake. Some players never open the Fish Index menu. They miss out on permanent multipliers that would make everything easier.
Deleting Diverse Brainrots
“This Rare is useless, I have Legendaries.” Maybe. But that Rare might catch fish your Legendaries can’t. Keep diversity until your index is complete.
Not Checking Time-Based Fish
If you only play during the day, you’ll never catch night fish. Check your index, identify gaps, and adjust your play schedule.
Rebirthing Before Milestones
You’re at 48 fish types. The 50 milestone gives +25% permanent bonus. Don’t rebirth yet. Catch 2 more fish types first.
Tracking Your Progress
The in-game Fish Index shows:
- Total fish types caught
- Which fish you have
- Which fish you’re missing (greyed out)
- Next milestone reward
Check it regularly. Identify gaps. Adjust your strategy.
Event Fish
Special events add limited-time fish:
- Christmas fish - December event
- Halloween fish - October event
- Anniversary fish - Game milestones
Event fish count toward your index. If you miss an event, those fish might not return for a year. Participate in events when possible.
Fish Index Checklist
Quick reference for index grinding:
- Check current fish count
- Identify next milestone
- Review missing fish types
- Hatch diverse brainrots
- Upgrade Fishing Luck
- Play at different times
- Participate in events
- Complete milestone before rebirth
More My Fishing Brainrots Content
- My Fishing Brainrots Guide - Complete beginner guide
- My Fishing Brainrots Rebirth Guide - Rebirth strategy
- My Fishing Brainrots Brainrot Tier List - All brainrots ranked
- My Fishing Brainrots Codes - Code status and rewards
Related Collection Guides
- Fisch Fish Tier List - Fish rankings in Fisch
- Grow a Garden Mutations Guide - Collection mechanics
- Pet Simulator 99 Pet Tier List - Pet collection rankings
Related Idle Games
- Fisch Guide - The OG fishing game
- Grow a Garden Guide - Similar collection systems
- Bee Swarm Simulator Codes - Another collection game
