Swimming on the edge of a mesmerizing bait ball

This school of horse-eye jacks form what is known as a bait ball. This technique allows the fish to confuse large predators and evade capture. These jacks can grow to a length of 101cm (almost 3.5 feet). and a weight of 13.5kg (almost 30 lbs). They prey on smaller fish and crustaceans. They also provide a source of food for larger fish such as sharks.
Bait balls form when fish are in the open with no structure to hide behind. This formation makes it difficult for predators to isolate and chase individual fish. Large fish have developed sophisticated means of ambushing or attacking the bait balls, making it possible to overcome the defensive advantages.
For a scuba diver encountering a bait ball is often a fascinating experience. The vast numbers of fish congregated together make a beautiful sight. This school of jacks was found in the Galapagos Islands.