Which animal has the highest level of testosterone than any other animal on earth?

Disagree with this answer. There was a guy I knew at school...

Delan1947, well, they are. Animals is just an umbrella term encompassing mammals, reptiles, amphibians, insects etc. They're all animals. Same as they're all "creatures"

Player Freewoman, Actually, they're able to swim up rivers too and aren't solely adapted to sea water.

Delan1947, yes they are. they are aquatic animals.

RedSeaDiver, An acquaintance, who happens to be a blackwater(?) diver (zero visibility) told me that Bull Sharks roam a goodly distance up the St. John’s River in Florida (fresh water). Image bumping into one of these guys while diving for relics in the St. John’s?

Player #1086786, I got it right without too much bnb thought!!

spoonyd81, you’re wring about that.

very interesting