In order to help narrow down where to find the fish I was missing from my collection book, I recorded each fish caught, which fish shape it came from, and what difficulty it was caught at. I just kept fishing until I had what I needed, so the sample sizes are pretty random.
This data is not every fish I have ever caught, but just recorded from the point where I started grinding to finish the book (I think I had ~20 empty spots at that point?).
There is now also a guide on steam: Steam Community :: Guide :: Completing your Sea Encyclopedia (Fish Collection Book)
Some stuff I noticed:
- A certain fish is only caught from one fish shape for the most part, the only exception to this was the Foureye Butterfly Fish, Emperor Angelfish, and Powderblue Tang which for some reason are caught from both the small fish shape and rare fish shape.
- Except for the abovementioned exceptions, a fish’s large variant will be caught from the same fish shape you caught its normal sized version from (ex: Clownfish and Large Clownfish are both caught from the small fish shape).
- The large variants of fish seem to favor Very Hard difficulty.
- Rarer fish such as the Cosmic Fish can be caught from difficulties other than Very Hard.
- You don’t have to buy a Sea Turtle with Sea Dollars because they are also caught from the rare fish shape.
Warning… tons of data tables ahead. May update with more data later on
Small fish shape (all caught with Lure)
| Fish name | Amount caught | % of total catch | Easy catches | Medium catches | Hard catches | Very Hard catches |
| Blue Arowana | 4 | 1,50% | 1 | 2 | 1 | |
| Blue Tang | 2 | 0,75% | 1 | 1 | ||
| Butterfly Fish | 5 | 1,87% | 3 | 2 | ||
| Clown Loach | 5 | 1,87% | 1 | 4 | ||
| Clown Triggerfish | 4 | 1,50% | 1 | 3 | ||
| Clownfish | 9 | 3,37% | 4 | 1 | 4 | |
| Demasoni Cichlid | 7 | 2,62% | 2 | 3 | 2 | |
| Desjardin Sailfin Tang | 8 | 3,00% | 4 | 1 | 3 | |
| Electric Blue Jack Dempsey | 4 | 1,50% | 1 | 2 | 1 | |
| Emperor Angelfish | 8 | 3,00% | 2 | 4 | 2 | |
| Foureye Butterfly Fish | 8 | 3,00% | 1 | 4 | 3 | |
| Large Blue Arowana | 6 | 2,25% | 1 | 1 | 4 | |
| Large Blue Tang | 4 | 1,50% | 4 | |||
| Large Butterfly Fish | 12 | 4,49% | 1 | 11 | ||
| Large Clown Loach | 3 | 1,12% | 3 | |||
| Large Clown Triggerfish | 5 | 1,87% | 1 | 1 | 3 | |
| Large Clownfish | 4 | 1,50% | 1 | 3 | ||
| Large Demasoni Cichlid | 2 | 0,75% | 1 | 1 | ||
| Large Desjardin Sailfin Tang | 3 | 1,12% | 1 | 2 | ||
| Large Electric Blue Jack Dempsey | 3 | 1,12% | 1 | 1 | 1 | |
| Large Emperor Angelfish | 4 | 1,50% | 4 | |||
| Large Foureye Butterflyfish | 3 | 1,12% | 1 | 1 | 1 | |
| Large Moorish Idol | 5 | 1,87% | 1 | 4 | ||
| Large Orange Surgeon | 3 | 1,12% | 3 | |||
| Large Orangespine Unicornfish | 7 | 2,62% | 1 | 2 | 4 | |
| Large Oreochromis | 4 | 1,50% | 1 | 3 | ||
| Large Piranha | 1 | 0,37% | 1 | |||
| Large Powderblue Tang | 5 | 1,87% | 5 | |||
| Large Rainbow Cichlid | 2 | 0,75% | 2 | |||
| Large Red Zebra Cichlid | 4 | 1,50% | 4 | |||
| Large Redtail Notho | 8 | 3,00% | 2 | 1 | 5 | |
| Large Reef Butterflyfish | 1 | 0,37% | 1 | |||
| Large Tiger Barb | 2 | 0,75% | 2 | |||
| Large Trewavas Cichlid | 2 | 0,75% | 1 | 1 | ||
| Large Yellow Angelfish | 3 | 1,12% | 3 | |||
| Large Yellow Lake Malawi Cichlid | 5 | 1,87% | 1 | 4 | ||
| Large Yellow Tang | 3 | 1,12% | 3 | |||
| Moorish Idol | 5 | 1,87% | 1 | 3 | 1 | |
| Orange Surgeon | 13 | 4,87% | 6 | 5 | 2 | |
| Orangespine Unicornfish | 9 | 3,37% | 4 | 4 | 1 | |
| Oreochromis | 6 | 2,25% | 1 | 1 | 4 | |
| Piranha | 7 | 2,62% | 1 | 3 | 3 | |
| Powderblue Tang | 8 | 3,00% | 2 | 4 | 2 | |
| Rainbow Cichlid | 3 | 1,12% | 1 | 1 | 1 | |
| Red Zebra Cichlid | 9 | 3,37% | 2 | 1 | 6 | |
| Redtail Notho | 6 | 2,25% | 3 | 2 | 1 | |
| Reef Butterflyfish | 7 | 2,62% | 3 | 4 | ||
| Tiger Barb | 4 | 1,50% | 2 | 2 | ||
| Trewavas Cichlid | 3 | 1,12% | 2 | 1 | ||
| Yellow Angelfish | 9 | 3,37% | 5 | 1 | 3 | |
| Yellow Lake Malawai Cichlid | 4 | 1,50% | 1 | 2 | 1 | |
| Yellow Tang | 6 | 2,25% | 4 | 1 | 1 | |
| Total Small Fish Caught | 267 |
Large Fish shape (all caught with Lure)
| Fish name | Amount caught | % of total catch | Easy catches | Medium catches | Hard catches | Very Hard catches |
| Amberjack | 3 | 1,20% | 1 | 2 | ||
| Amur | 5 | 1,99% | 2 | 2 | 1 | |
| Arapaima | 4 | 1,59% | 2 | 1 | 1 | |
| Archerfish | 4 | 1,59% | 2 | 2 | ||
| Atlantic Cod | 7 | 2,79% | 2 | 5 | ||
| Barracuda | 10 | 3,98% | 5 | 2 | 3 | |
| Black Redeye | 2 | 0,80% | 2 | |||
| Black Sea Bass | 6 | 2,39% | 1 | 2 | 3 | |
| Black Spotted Grunt | 5 | 1,99% | 2 | 2 | 1 | |
| Brown Trout | 5 | 1,99% | 2 | 1 | 2 | |
| Carp | 4 | 1,59% | 1 | 3 | ||
| Cobia | 4 | 1,59% | 2 | 1 | 1 | |
| Cubera Snapper | 1 | 0,40% | 1 | |||
| Electric Catfish | 4 | 1,59% | 1 | 3 | ||
| Frontosa | 7 | 2,79% | 1 | 1 | 5 | |
| Gold Redeye | 6 | 2,39% | 3 | 2 | 1 | |
| Koi | 8 | 3,19% | 2 | 4 | 2 | |
| Large Amberjack | 3 | 1,20% | 2 | 1 | ||
| Large Amur | 3 | 1,20% | 3 | |||
| Large Arapaima | 4 | 1,59% | 2 | 1 | 1 | |
| Large Archerfish | 4 | 1,59% | 4 | |||
| Large Atlantic Cod | 4 | 1,59% | 1 | 3 | ||
| Large Barracuda | 1 | 0,40% | 1 | |||
| Large Black Redeye | 3 | 1,20% | 3 | |||
| Large Black Sea Bass | 3 | 1,20% | 1 | 2 | ||
| Large Black Spotted Grunt | 4 | 1,59% | 1 | 3 | ||
| Large Brown Trout | 2 | 0,80% | 1 | 1 | ||
| Large Carp | 1 | 0,40% | 1 | |||
| Large Cobia | 2 | 0,80% | 2 | |||
| Large Cubera Snapper | 4 | 1,59% | 4 | |||
| Large Electric Catfish | 6 | 2,39% | 1 | 1 | 4 | |
| Large Frontosa | 1 | 0,40% | 1 | |||
| Large Gold Redeye | 1 | 0,40% | 1 | |||
| Large Koi | 2 | 0,80% | 1 | 1 | ||
| Large Mackerel | 4 | 1,59% | 1 | 3 | ||
| Large Mahi Mahi? | ||||||
| Large Miniata Grouper | 3 | 1,20% | 1 | 2 | ||
| Large Orange-spotted Spinefoot | 2 | 0,80% | 1 | 1 | ||
| Large Peacock Bass | 6 | 2,39% | 1 | 1 | 4 | |
| Large Perch Fish | 3 | 1,20% | 3 | |||
| Large Pike | 3 | 1,20% | 1 | 2 | ||
| Large Rabbitfish | 2 | 0,80% | 2 | |||
| Large Red Eye | 3 | 1,20% | 2 | 1 | ||
| Large Red Snapper | 4 | 1,59% | 1 | 1 | 2 | |
| Large Salmon | 3 | 1,20% | 1 | 2 | ||
| Large Sea Bass | 1 | 0,40% | 1 | |||
| Large Shortfin Corvina | 2 | 0,80% | 1 | 1 | ||
| Large Streaked Spinefoot | 3 | 1,20% | 3 | |||
| Large Trout | 4 | 1,59% | 4 | |||
| Mackerel | 7 | 2,79% | 1 | 3 | 3 | |
| Mahi Mahi | 7 | 2,79% | 2 | 2 | 3 | |
| Miniata Grouper | 5 | 1,99% | 1 | 1 | 3 | |
| Orange-spotted Spinefoot | 2 | 0,80% | 2 | |||
| Peacock Bass | 2 | 0,80% | 1 | 1 | ||
| Perch Fish | 8 | 3,19% | 3 | 5 | ||
| Pike | 6 | 2,39% | 1 | 3 | 2 | |
| Rabbitfish | 9 | 3,59% | 2 | 4 | 3 | |
| Red Eye | 4 | 1,59% | 1 | 3 | ||
| Red Snapper | 5 | 1,99% | 4 | 1 | ||
| Salmon | 7 | 2,79% | 3 | 2 | 2 | |
| Sea Bass | 3 | 1,20% | 1 | 2 | ||
| Shortfin Corvina | 3 | 1,20% | 2 | 1 | ||
| Streaked Spinefoot | 5 | 1,99% | 1 | 4 | ||
| Trout | 2 | 0,80% | 1 | 1 | ||
| Total Large Fish Caught | 251 |
Rare Fish shape (all caught with Worms/Mighty Balls)
| Fish name | Amount caught | % of total catch | Easy catches | Medium catches | Hard catches | Very Hard catches |
| All Knowing Pufferfish | 3 | 0,40% | 1 | 2 | ||
| Bass Fish | 2 | 0,27% | 1 | 1 | ||
| Blob Fish | 25 | 3,33% | 12 | 8 | 5 | |
| Blue Checkerboard Discus | 22 | 2,93% | 7 | 10 | 5 | |
| Blue Mandarin | 22 | 2,93% | 5 | 8 | 9 | |
| Blue Marlin | 12 | 1,60% | 2 | 2 | 1 | 7 |
| Cosmic Fish | 3 | 0,40% | 1 | 2 | ||
| Cuttlefish | 24 | 3,20% | 7 | 7 | 10 | |
| Emperor Angelfish | 27 | 3,60% | 11 | 10 | 6 | |
| Fangtooth | 35 | 4,66% | 12 | 14 | 9 | |
| Foureye Butterfly Fish | 27 | 3,60% | 9 | 11 | 7 | |
| Gold Fish | 3 | 0,40% | 1 | 1 | 1 | |
| Large Blob Fish | 14 | 1,86% | 4 | 1 | 3 | 6 |
| Large Blue Checkerboard Discus | 12 | 1,60% | 2 | 2 | 8 | |
| Large Blue Mandarin | 15 | 2,00% | 1 | 1 | 13 | |
| Large Blue Marlin | 15 | 2,00% | 4 | 2 | 1 | 8 |
| Large Cuttlefish | 14 | 1,86% | 2 | 12 | ||
| Large Fangtooth | 16 | 2,13% | 1 | 2 | 2 | 11 |
| Large Leopard Coral Grouper | 11 | 1,46% | 1 | 2 | 8 | |
| Large Lion Fish | 10 | 1,33% | 1 | 2 | 7 | |
| Large Manta Ray | 17 | 2,26% | 2 | 3 | 1 | 11 |
| Large Octopus | 12 | 1,60% | 2 | 2 | 2 | 6 |
| Large Pufferfish | 11 | 1,46% | 2 | 1 | 8 | |
| Large Red Leopard Discus | 13 | 1,73% | 1 | 1 | 11 | |
| Large Royal Angelfish | 12 | 1,60% | 2 | 3 | 7 | |
| Large Skeleton Fish | 4 | 0,53% | 2 | 1 | 1 | |
| Large Stingray | 17 | 2,26% | 4 | 3 | 10 | |
| Large Sunfish | 18 | 2,40% | 1 | 1 | 16 | |
| Large Tiger Turquoise Discus | 15 | 2,00% | 3 | 1 | 11 | |
| Large Yellow Mandarin | 11 | 1,46% | 3 | 1 | 7 | |
| Leopard Coral Grouper | 25 | 3,33% | 9 | 6 | 10 | |
| Letter Fish | 4 | 0,53% | 1 | 1 | 2 | |
| Lion Fish | 27 | 3,60% | 9 | 11 | 7 | |
| Manta Ray | 20 | 2,66% | 4 | 9 | 7 | |
| Octopus | 23 | 3,06% | 7 | 4 | 12 | |
| Powderblue Tang | 25 | 3,33% | 8 | 7 | 10 | |
| Pufferfish | 21 | 2,80% | 8 | 6 | 7 | |
| Red Leopard Discus | 33 | 4,39% | 12 | 11 | 10 | |
| Royal Angelfish | 22 | 2,93% | 6 | 10 | 6 | |
| Sea Turtle | 4 | 0,53% | 4 | |||
| Skeleton Fish | 2 | 0,27% | 2 | |||
| Stingray | 14 | 1,86% | 5 | 4 | 5 | |
| Sunfish | 28 | 3,73% | 10 | 12 | 6 | |
| The Cat Fish | 4 | 0,53% | 1 | 3 | ||
| The Fisherman | 6 | 0,80% | 1 | 1 | 2 | 2 |
| Tiger Turquoise Discus | 24 | 3,20% | 8 | 11 | 5 | |
| Time Fish | 1 | 0,13% | 1 | |||
| Wizard Fish | 5 | 0,67% | 1 | 1 | 1 | 2 |
| Yellow Mandarin | 21 | 2,80% | 5 | 7 | 9 | |
| Total Fish Caught | 751 |
Items Fish shape (all caught with Curly Grubs)
| Catch name | Amount caught | % of total catch | Easy catches | Medium catches | Hard catches | Very Hard catches |
| Bag of Units | 1 | 0,20% | 1 | |||
| Barrel Of Trash | 7 | 1,40% | 2 | 5 | ||
| Blue Sea Urchin | 15 | 3,00% | 4 | 4 | 7 | |
| Broken Bottle | 10 | 2,00% | 5 | 4 | 1 | |
| Broken Potted Plant | 9 | 1,80% | 3 | 2 | 4 | |
| Broken Soda Can | 12 | 2,40% | 4 | 3 | 5 | |
| Broken Television | 8 | 1,60% | 3 | 2 | 3 | |
| Broom | 10 | 2,00% | 2 | 3 | 5 | |
| Candy Wrapper | 10 | 2,00% | 3 | 4 | 3 | |
| Cigs | 11 | 2,20% | 3 | 6 | 2 | |
| Common Starfish | 12 | 2,40% | 4 | 1 | 1 | 6 |
| Cool Crab | 2 | 0,40% | 1 | 1 | ||
| Cooler | 8 | 1,60% | 4 | 3 | 1 | |
| Crab | 1 | 0,20% | 1 | |||
| Crossword Magazine | 10 | 2,00% | 2 | 8 | ||
| Disco Duck | 1 | 0,20% | 1 | |||
| Elevator Music | 5 | 1,00% | 1 | 4 | ||
| Gem | 2 | 0,40% | 2 | |||
| Gold | 4 | 0,80% | 1 | 2 | 1 | |
| Home Cooking Magazine | 10 | 2,00% | 3 | 1 | 6 | |
| Large Common Starfish | 15 | 3,00% | 3 | 2 | 3 | 7 |
| Large Murex Shellfish | 19 | 3,80% | 3 | 1 | 7 | 8 |
| Large Mussel | 21 | 4,20% | 6 | 2 | 5 | 8 |
| Large Oyster | 30 | 6,00% | 4 | 7 | 5 | 14 |
| Large Red Knob Starfish | 18 | 3,60% | 5 | 3 | 3 | 7 |
| Message in a Bottle | 19 | 3,80% | 3 | 7 | 4 | 5 |
| Murex Shellfish | 19 | 3,80% | 4 | 5 | 10 | |
| Mussel | 17 | 3,40% | 6 | 4 | 2 | 5 |
| Old Newspaper | 11 | 2,20% | 4 | 1 | 6 | |
| Oyster | 17 | 3,40% | 3 | 3 | 2 | 9 |
| Party Crab | 2 | 0,40% | 1 | 1 | ||
| Pile of Gold | 1 | 0,20% | 1 | |||
| Plastic Straw | 8 | 1,60% | 1 | 2 | 5 | |
| Plastic Toyblock | 9 | 1,80% | 3 | 3 | 3 | |
| Red Knob Starfish | 16 | 3,20% | 3 | 2 | 5 | 6 |
| Red Sea Urchin | 15 | 3,00% | 4 | 3 | 4 | 4 |
| Rubber Duck | 16 | 3,20% | 3 | 2 | 5 | 6 |
| Ruined Paper Ticket | 8 | 1,60% | 2 | 3 | 3 | |
| Sea Dollar | 19 | 3,80% | 2 | 3 | 1 | 13 |
| Shopping Cart | 8 | 1,60% | 2 | 1 | 5 | |
| Soggy Cardboard Box | 9 | 1,80% | 3 | 2 | 4 | |
| Tin Can | 9 | 1,80% | 1 | 3 | 5 | |
| Tire | 3 | 0,60% | 2 | 1 | ||
| Trash Bag | 11 | 2,20% | 2 | 5 | 4 | |
| Trash Can Lid | 11 | 2,20% | 4 | 4 | 3 | |
| Treasure Chest o' Units | 2 | 0,40% | 1 | 1 | ||
| Used Coffee Cup | 9 | 1,80% | 3 | 3 | 3 | |
| Used Spray Can | 6 | 1,20% | 1 | 2 | 3 | |
| Wooden Palette | 12 | 2,40% | 4 | 3 | 5 | |
| Total Items Caught | 500 |
Rare Items Fish shape (all caught with Curly Grubs/Mighty Balls)
| Catch name | Amount caught | % of total catch | Easy catches | Medium catches | Hard catches | Very Hard catches |
| Barrel Of Trash | 16 | 2,41% | 6 | 4 | 6 | 0 |
| Bongos | 14 | 2,11% | 3 | 5 | 0 | 6 |
| Broken Bottle | 16 | 2,41% | 6 | 6 | 4 | 0 |
| Broken Potted Plant | 14 | 2,11% | 5 | 5 | 4 | 0 |
| Broken Soda Can | 9 | 1,36% | 2 | 3 | 4 | 0 |
| Broken Television | 9 | 1,36% | 2 | 4 | 3 | 0 |
| Broom | 15 | 2,26% | 4 | 4 | 7 | 0 |
| Candy Wrapper | 17 | 2,56% | 7 | 8 | 2 | 0 |
| Cigs | 9 | 1,36% | 2 | 3 | 4 | 0 |
| Cooler | 16 | 2,41% | 5 | 4 | 7 | 0 |
| Crossword Magazine | 12 | 1,81% | 4 | 3 | 5 | 0 |
| Disco Duck | 18 | 2,71% | 3 | 6 | 1 | 8 |
| Gem | 20 | 3,02% | 3 | 1 | 3 | 13 |
| Home Cooking Magazine | 12 | 1,81% | 3 | 6 | 3 | 0 |
| Lightning in a Bottle | 20 | 3,02% | 2 | 5 | 5 | 8 |
| Message in a Bottle | 16 | 2,41% | 2 | 4 | 3 | 7 |
| Nuke Button | 8 | 1,21% | 2 | 1 | 2 | 3 |
| Old Newspaper | 10 | 1,51% | 7 | 1 | 2 | 0 |
| Pirate Gun | 9 | 1,36% | 1 | 4 | 0 | 4 |
| Plastic Straw | 19 | 2,87% | 6 | 6 | 7 | 0 |
| Plastic Toyblock | 12 | 1,81% | 3 | 4 | 5 | 0 |
| Rubber Duck | 25 | 3,77% | 2 | 4 | 6 | 13 |
| Ruined Paper Ticket | 18 | 2,71% | 7 | 4 | 7 | 0 |
| Screamy Boy | 1 | 0,15% | 0 | 0 | 0 | 1 |
| Scuba Tree | 27 | 4,07% | 3 | 3 | 5 | 16 |
| Sea Dollar | 157 | 23,68% | 30 | 35 | 21 | 71 |
| Shopping Cart | 13 | 1,96% | 8 | 2 | 3 | 0 |
| Soggy Cardboard Box | 13 | 1,96% | 5 | 5 | 3 | 0 |
| Speedy Crab | 22 | 3,32% | 4 | 5 | 5 | 8 |
| Tin Can | 13 | 1,96% | 6 | 7 | 0 | 0 |
| Tire | 15 | 2,26% | 9 | 3 | 3 | 0 |
| Trash Bag | 23 | 3,47% | 4 | 9 | 9 | 1 |
| Trash Can Lid | 10 | 1,51% | 4 | 1 | 5 | 0 |
| Used Coffee Cup | 12 | 1,81% | 5 | 0 | 7 | 0 |
| Used Spray Can | 12 | 1,81% | 3 | 5 | 4 | 0 |
| Wooden Palette | 11 | 1,66% | 4 | 4 | 3 | 0 |
| Total Fish Caught | 663 |