Migrant, migrator: an organism that migrates.

Migrate, migrating: the process of migration.

Migration: periodical movement of organisms between alternative habitats. In the marine environment many organisms exhibit dual vertical migration resulting in a shallow occurrence during night and a deeper distribution during daytime. There are also ontogenetic migrations: organisms that migrate from one habitat to another during development form one life stage to another. For instance many juvenile fish have a shallow occurrence, but deepen their distribution when maturing.

Migratory: of, or relating to, or characterized by migration.

Alternative forms for migrant : migrate, migrating, migration, migrator, migratory.