An ichthyologist
A person who fishes is called an angler. It begins with the letter a.
fisher
A person who fishes as a hobby is commonly referred to as an angler or a fisherman.
a person that studies gems is called a gemologist.
The Person Who studies about mamals , he is called mamalogist....
A person who studies animals is called a zoologist.
A person who studies physics is called a physicist, a person who studies chemistry is called a chemist, and a person who studies biology is called a biologist.
A person who studies the mind and behavior is called a psychologist.
A person who studies or writes history is called a historian.
Alligators of reptiles, so one who studies them is called a herpetologist.
A person who studies optometry is called an optometry student or an optometry student.
A person who studies a lot is often called a "bookworm" or a "knowledge enthusiast."