Sailfish

Common Name: Sailfish (Indo pacific) Scientific Name: Istiophorus platypterus

As can be seen from the over large eye this fish spends alot of its time in deep water, feeding mainly on squid.
Gets its name from its dorminant dorsal fin, which can and is often raised as you see in the picture.

There are no external features to distinguish the sexes and, while it is generally believed that males and females reach equivalent weights, the larger fish are usually female. Sailfish may grow to 100kg with an average size of between 25 and 40kg. Males are not mature until at least 20-25kg, females closer to 30-35kg. Presumed spawning activity is associated with fish generally in excess of 40kg. Little is known of their age and growth except evidence from a tagged and recaptured Atlantic sailfish estimated to be at least 15 years old.

There is a great tendency amongst sailfish to form feeding aggregations. Cooperative feeding activity can be up to 30-40 fish. Their diet appears to be considerably broader than for other billfish, which may reflect their year-round predominance in coastal waters.