Snorkeling in Galapagos is quite an experience. Almost every day you have the opportunity to do it, as we are moving from island to island. We don't have coral reefs, but a great variety of tropical fishes, like this polarized school of black-striped salema shown in the picture. Many fish congregate in groups commonly called schools. The three primary reasons for this behavior are predator protection, cooperative hunting and breeding purposes. It is theorized that when schooling fish pack together and move in unison, predators have a difficult time picking out a single target, and in the confusion of numbers, all members of the school may survive the attack.
There are several types of congregations. One of these is a polarized school in which all fish swim together in the same direction, at the same speed, keeping the same relative distance between one another.
