[0]https://a-z-animals.com/articles/the-10-animals-with-the-hig...
[0]https://a-z-animals.com/articles/the-10-animals-with-the-hig...
While humans together with domestic animals exceed the mass of all other terrestrial animals, fish are estimated to exceed the mass of all terrestrial animals (for now, but they are decreasing).
Nonetheless, all animals together are much less than bacteria, which are less than plants.
[0] https://researcharchive.calacademy.org/research/ichthyology/...
If we say the fish is 2cm wide and 7.5cm long (average length according to wiki) That's 23cm^3 Assume the fish is neutrally bouyant so it's 1g/cm^3(I know deep sea pressures change density, but let's just go with this)
1 quadrillion*23g= 23 trillion kg
So like... 1/32 of that is still around 100x bigger than the trees.