Custom fishing is a mechanic in game that allows for all players to catch fish that are not default in Minecraft. All of these fish have custom textures, names, and lengths. They can be sold at any time with the commands /sellfish. To see your fishing bag, do /fishingbag.
Fishing Competitions
Fishing competitions are a server wide competition between all players! This is a friendly, fun competition, where you can win rewards like a fishing key, or money. To figure out when the next fishing competition is, you can use the command /emf next. During a competition to see the leaderboard, you can see the person winning on the bossbar. The top 10 players of the competition all receive a reward.