Precociality and altriciality
classification of birds based on the condition of the young after hatching / From Wikipedia, the free encyclopedia
In the study of biology of birds and mammals, some babies are born needing a lot of care because they can't move much. These babies are called altricial. Others are ready to move and do things on their own soon after they are born. These babies are called precocial. Precocial babies are often ready to leave their home (like a nest) very soon after they are born or hatched.
In fish, the difference is about if a baby fish is born with a stomach ready to digest food. Precocial fish babies have a stomach from the start, but altricial fish babies do not.[1]