most animals have to be 'trained' to 'trust' humans around babies. Like horses and dogs can learn to tolerate it, but most still display signs of nervousness when humans or other animals are around. I use the term 'trust' loosely, in that they can't trust, like human can trust. Its not a conscious decision.
"Oh I'll 'trust' this human not to smash or eat my eggs." A fish will never think that. But IMO other animals can learn to accept it, or tolerate humans, at different levels. One pony couldn't care less what you did with her foal, another tried to stomp you in the ground. My doberman didn't care what i did with her puppies, but let a stranger just come in the house, far from the puppies in the bedroom and she went for their throat.
Humans should never completely trust a protective mommy or daddy anything. Although a Betta probably couldn't inflict a mortal wound ^.^)
IMO by Me.