Elijah is an active hiker, tennis player, and cross-country runner. He also plays the piano and the trombone. Because he likes "discovering new things," Elijah would like to pursue a career in science. Elijah's father is his mentor: "My father, who is a scientist, has always asked himself interesting scientific questions. He has inspired me to be like him in these ways."
Elijah keeps live-bearing freshwater fish. He noticed that the behavior of the offspring changed as soon as he moved them away from the adult fish. He thought this might be an escape behavior.
Elijah bought pregnant guppies and platys. He set up a small nursery tank and marked swimming levels of 3 cm (bottom of the tank) up to 15 cm (top of the tank). He immediately moved newborn fish into the nursery tank and recorded how many swam at each level. He repeated the experiment with an adult fish in the tank. He found that newborn fish alone swim at all depths, but in the presence of an adult fish, all newborns surfaced. This response was most pronounced when the fish were three days old. Fish older than a week no longer responded to the adult. He concluded that baby fish are born with strong survival instincts.
