The study specifically of fish is called Ichthyology. A person who works in that field would be an Ichthyologist.
Botanists are people who study plants and nature.
a person who studys biographics
A fishery bioligist studys fish out of water to see what there type is.
someone who studys insects PS i would like to be one
A selenographer studys maps of the moon.
Geology.
a cryologist
a botanist
Astronomer
Geology.
Oceanographers o
A person who studies flying saucers is called a Ufologist.