So now that I went over fishing mechanics,now i'll go over aquatic animals!

1.fish:
A passive mob with 2health,spawns in any biome as long as there's enough water,spawns in groups of 6-18,drop bone shards and raw fish(cooked if death by fire),ocelots,bears,seals,squid,guardians, dolphins,sharks,and a few other mobs will kill fish(and any other fish entities except for sharks,and stingrays), swims around,destroy water plants,seaweed,Lilly pads,vines that manage to grow right above the water's surface,and shrimp,follows a fishing rod's bobber when put in the water,And also have multiple skins with different colors.

2.sharks:
sharks are a neutral mob with 14 health,that gives of 2.5 hearts of damage when attacked by one,spawns in ocean,beach,and reef biomes usually but will sometimes spawn in tropical biome to,orcas,guardians,and dolphins(when the dolphins get attacked)will kill sharks,sharks will kill every small and large fish,barracudas, dolphins,seals,stingrays,sea turtles,orcas,squids,whales,most land animals,and when attacked by,guardians.when killed,drop shark fins,bone shards,and raw shark meat(cooked if death by fire),2 shark fins and a bowl,will make shark fins soup,sharks destroy wooden boats if a mob it kills is on it,and shark have multiple skins,and those skins are based off great white,tiger,making,black/white tip reef,lemon,hammer head,goblin,frilled,blunt nose six gilled,and bull sharks.

3.squids:
Squids are passive mobs with 8 health,are capable to spawn in every biome,in elevations from sea level,to 28 blocks below that,they will kill fish,reef fish,shrimp,and crabs,and the mobs that will kill squids are sharks,dolphins,orcas,certain large fish,guardians,barracudas,and a few other mobs,when they die,will drop ink sacks,and raw calamari(Cooked if death by fire),when attacked they will swim away really fast,while they spray ink particles at the things that attacked it,and the ink particles will but the blindness potion effect for 6 seconds,and come in 2 skins,squids and octopus.

4.stingrays:
they're neutral mobs with 4 health,spawn in ocean,reef,beach,and tropical biomes,and they will bury in dirt,clay,sand,gravel,mud,and pepple blocks(like stingray AI on Survival Craft),and when it buries in the sand,If an entity walks on it will give then 1 heart of damage,and the poison effect for 4 seconds,they will kill shrimp and crabs,while sharks,dolphins,certain large fish,orcas,and barracudas will kill stingrays,when killed drop bone shards,and raw shark meat(cooked if death by fire),and spawn with different skins.

5.dolphins:
dolphins are neutral mobs with 10 health,give of 1.5 hearts of damage each time it attacks you,spawns in ocean,beach,reef,and tropical biomes,jumps out water occasionally,make dolphin sounds,are a bluish-gray in color, (like whales,and orcas,will drown if not surfacing in 10 minutes,when they do surface they will make water spray particles just in front of their dorsal fins(like orca and bauluga whale AI on Survival Craft),like wolves,they will attack in packs,they spawn in groups of 10-28,sharks,orcas,guardians,and barracudas will kill dolphins,and dolphins will kill fish,reef fish,large fish,stingrays,sqiud,shrimp,crabs,and flashlight fish,but when attacked,will kill guardians,sharks,orcas,anglerfish,and barracudas,when they die,they drop bone-shards and raw fish(it's what the dolphin ate),and not sure if i'll be cruel enough to suggest raw dolphin meat,or cooked if it died by fire,and dolphins can be ridden on with a saddle.

6.Orcas:
these are hostile mobs with 22 health,they give you 3 hearts of damage each time it attacks you,spawns in Ocean biomes,and more often in oceans nearby cold biomes,spawns in groups of 4-8,make whale sounds,orcas will kill almost every animal in the game,sharks,dolphins,and guardians will kill orcas,and when killed,will drop bone shards,4-10 raw fish,and raw whale(cooked if death by fire),and will destroy wooden boats if a mob it kills is on it.

7.barracudas:
A hostile mob with 10 health,and give of 2 hearts of damage each time it attacks,they will kill all fish,squids,crabs,stingrays,sea turtles,sea gulls,and dolphins,and sharks,dolphins,orcas,and guardians will kill barracudas,when killed,will drop bone shards,and raw fish,spawn in ocean,and reef biomes,and their skin will be based off of the great barracuda species.

8.Whales:
these are passive gentle giant type mobs,with 80 health,make whale sounds,sometimes breach out of the water,only kill shrimp,but however,sharks,and Orcas will kill whales,when whales die,will drop bone shards,and raw whale(cooked if death by fire),spawn in ocean,beach,and reef biomes,and have multiple skins,which are based of of blue,humpback,right,and fin whales.

9.jelly fish:
Has 6 health,spawn in groups of 6,they float at the surface,slowly moving in one direction for 2.5 world chunks (or until hits a block),then moving to another direction for the same distance,and repeat that processes again and again,when any entity except other jelly fish,man-o-war fish,or sea turtles,touches a jelly fish will get effected by poison effect for 6 seconds,when killed drop slime balls,spawns in ocean,beach,reef,and tropical biomes,if you use a glass bottle on them,you will get a potion of poison,and have skins with different colors.

10.piranha:
A neutral mob,with 6 health,that attacks in packs,spawns in groups of 6-10,gives of 1 heart of damage each time it attacks you,spawns in jungle,and tropical biomes,will kill small land animals,fish,reef fish,ocelots,and dolphins,and ocelots,crocodiles,and dolphins will kill piranhas,when killed,drop bone shards,and raw piranha(cooked if death by fire),and will have multiple skins,red belly piranha,and other more peaceful species(such as marbled piranha).

11.crocodiles:
they are hostile mobs with 16 health that give of 2.5 hearts of damage,spawns not to often in swamp,slightly less commonly in jungle,and rare in tropical biomes,will kill almost every animal in the game,and ocelots,and dolphins will kill crocodiles,when killed drop bone shards,scales,and raw fish,makes crocodile sounds,and will spawn with different skins.

12.seals:
they are passive mobs with 10 health,Spawns in beach biomes(especially in stone beaches,and beaches next to colder,and tropical biomes),kills fish,squid,reef fish,stingrays,shrimp,and crabs,while sharks,barracudas,bears,crocodiles and Orcas will kill seals,makes seal sounds,when killed drop bone shards,fur,and raw seal(cooked if death by fire),and will spawn with different skins.

13.frogs:
they will spawn in warmer biomes,makes frog croaking sounds,kill worms,beetles,and silverfish,and vultures,coyotes,wolves,bass,and crocodiles kill frogs,when killed drop bone shards,and raw frog legs(cooked if death by fire)and raw frog legs can make you sick so you have to cook it!,they will jump around,climb walls,or swim around,can be feed/breed with worms,beetles,and silverfish,and spawn with multiple skins.

14.seagulls:
these passive mobs,with 4 health,have almost the same AI as birds,and drop the same stuff,but seagulls can also drop raw fish to,they spawn on beaches and tropical biomes,kill fish,reef fish,shrimp,squid,and crab,and all of bird's predators,along with sharks,orcas,and barracudas will kill seagulls,make seagull squawking sounds,and spawn with different skins.

There's more but this is enough of this forum post right now,so see you in the next forum! :D