Picasso triggerfish

Lore & Background

The Picasso triggerfish lives in the reefs and sandy areas of coral reefs, where it eats just about anything that comes along, mostly invertebrates and reef algae. It is always restlessly swimming and vigorously protects its territory against intruders, including divers, especially when guarding eggs. Its relatively small size makes it less dangerous than the larger titan triggerfish. The fish moves through the water using waving motions in its dorsal and anal fins, allowing precise forward, backward, or hovering movement above the reef. This enables it to back out of crevices more easily than other unidirectional fish. Both sexes guard territories, some maintaining a territory for eight years or longer, with males holding territories significantly longer than females. A typical male territory may overlap with one to five female territories, and the mating system is described as haremic, though not much is known about it. Pair-spawning occurs around sunrise, with egg masses attached to sand, coral rubble, or algae. Mothers guard and care for the eggs for about 12–14 hours, fanning them with pectoral fins and chasing away intruders. Maternal care is effective in preventing predation, and experimental removal of mothers reduced survival to almost nothing.

Reader's Guide

The Picasso triggerfish is a notable member of the reef ecosystem due to its territorial behavior and role as a generalist feeder, consuming invertebrates and algae. Its ability to move precisely in any direction using dorsal and anal fin waving motions allows it to navigate crevices and defend its territory effectively. In reproduction, maternal care is critical: mothers guard eggs for 12–14 hours, fanning them for aeration and removing predators, while males do not provide care due to the cost of lost mating opportunities in their haremic system. The species has been studied for its vision, possessing single cones sensitive at 413 nm and double cones with opsins peaking at 480 nm and 530 nm. Behavioral research suggests the double cone members act as independent color channels, giving the fish trichromatic vision similar to humans.

Did You Know?

• The Picasso triggerfish can move forwards, backwards, or hover using its dorsal and anal fins.
• Experimental removal of mothers reduced egg survival to almost nothing.
• The species has trichromatic vision, with double cone members acting as independent color channels.