Mob Cap appears to be increased

What I expected to happen was...:
about 15 bats in a single player setting

about 15 aquatic mobs in a river in a single player setting

70 hostile mobs in a single player setting

What actually happened was...:
f3 screen shows an excessive number of entities

kill command confirms 170-180 bats

70+ squid

125+ salmon

switching from normal mode to peaceful, the entity count drops from 6-800 down to about 475

Steps to Reproduce:

Load up a world

using the f3 screen, see the number of mobs.