Entities underwater launch the player (not other entities, as far as i can tell)

I used salmon, cod, and turtle spawn eggs for a fish tank. While using the eggs, i noticed that contact with any mob while underwater launched the player. (effect on items and other entities unknown)

What should have happened was minor entitycramming/entitycollision, the entities are pushed apart.

What happened was the player was launched by the entity (fish, drowned, turtles)

Steps to reproduce:

1. get a mob spawn egg
2. spawn it in water
3. contact the mob (affects creative, survival, and adventure)