Salmon

Salmon are common passive mobs found in oceans and rivers.

Java Edition
Salmon spawn in groups of 1–5 in cold or frozen oceans, as well as their deep variants. They also spawn in rivers and frozen rivers.

Bedrock
Salmon spawn underwater at 12–32 blocks away from the player. Salmon spawn in groups of 3–5 in lukewarm, cold, normal, frozen oceans, their deep variants and rivers (including frozen rivers). In addition, salmon spawn on the surface (i.e., there must not be a spawnable block above the spawn location with a non-solid block on top). Salmon spawn in small, normal, and large sizes. 31.5% spawn as small, 52.6% spawn as normal, and 15.7% spawn as large.

Drops
When killed, salmon drop:
 * when killed by a player or tamed wolf.
 * 1 (1  if killed while on fire.)
 * 1 (5% chance).
 * 1 s (25% chance) if salmon size is small or medium.
 * 1-2 s (25% chance) if salmon size is large.
 * 1 s (25% chance) if salmon size is small or medium.
 * 1-2 s (25% chance) if salmon size is large.

Behavior
Salmon tend to swim in schools (a maximum of seven salmon per school). Salmon are able to swim up approximately 4–5 blocks in waterfalls.

The player may collect salmon by a water bucket on it, which gives the player a bucket of salmon. Salmon placed with buckets do not despawn naturally. When that fish bucket is against a block, it empties the bucket, placing water with that fish swimming in it. $$, an empty bucket may be used as well.

Weaknesses
Salmon are unable to survive out of water. Outside of water, they flop around for a while until eventually they start to suffocate and die. Salmon flip around on their sides. $$, they rotate when flipping. Salmon also cannot swim or breathe in cauldron water.

$$, salmon have a weakness to weapons that have the Impaling enchantment, which also affects other fish and water/ocean mobs (including Drowned).

Entity data
Salmon have entity data associated with them that contain various properties of the mob.

Trivia

 * They appear to be influenced by real-life Sockeye salmon.
 * Salmon also spawn in rivers because in the real-world in Autumn, salmon travel upstream, returning from the ocean to the streams where they were born, to lay eggs.
 * The salmon's ability to swim up waterfalls is actually based off salmon leaping into and above waterfalls in the real-world so they can get to the streams they were born in.
 * The achievement "I am a Marine Biologist" is a reference to Seinfeld Season 5 Episode 14.