Satellite images show that the sea surface temperature of the Caribbean is warm throughout the year, as would be expected of an area just above the equator. Gulf of Maine fish tend to be full-bodied and streamlined, built for swimming long distances in large schools. Or they may be adapted for living on the ocean floor. Coral reef fishes are often disc-shaped, flattened from side to side, so they can slip into crevices in the reef. Schools of cold water fishes range across broad expanses of ocean, while the city dwellers of the coral reef compete for cramped quarters.
Reef fishes occupy many different levels, like apartment dwellers in high-rise buildings.
Once an animal sets up housekeeping in one area, it rarely moves unless it is forcibly evicted by a new tenant. So many creatures crowd into the coral reef that they must maintain two different shifts to accommodate all the residents. The coral reef community pulses both day and night.