Find the word definition

Wikipedia
Triacanthidae

Triacanthidae, commonly known as triplespines or tripodfishes, is a family of Indo-Pacific fishes. It is classified in the order Tetraodontiformes, along with the pufferfishes and the ocean sunfish. The family consists of seven species in four genera, in addition to one extinct genus that only is known from fossils.

Much like their relatives the triggerfish and the filefish, the triplespines's first ray of the dorsal fin is formed to a spine. Further, they have two spines in place of their ventral fins. They have sharp and heavy teeth, which they use to eat hard-shelled molluscs and crustaceans. They also have the unique ability to see ultraviolet light. Their ability to see ultraviolet light is similar to the vision of Goldfish.

Not much is known about how the fish live. They are essentially offshore fish that only come close to land occasionally. They range from in length.