I have noticed that there is an inconsistency with the rarity of the Neon Knightfish. In the fish collections, this fish is indicated as a Rare fish and grants 25 mastery like the other Rare fishes would. However, the Saltwater Swordfish, Lava Lancefish, and Candied Cutterfish (the water, lava, and chocolate swordfish variants) are all Uncommon.

I believe this is a mistake with the neon swordfish variant and it should be Uncommon for consistency with the rest of the liquids. I have included a screenshot of the current 3 Uncommon swordfishes in the game for further clarification (note that there is an empty row just for the Neon Knightfish, which i think should just be the same rarity as the rest).

https://imgur.com/a/4GgBB