Triggerfish

The ocean is a non-stop wonder of color, life and a continuous playground to discover some of the most beautiful creatures mother earth has to show. 

Triggerfish easily find themselves among these wonders, boasting bright, vibrant colors, distinct lines and spots, and a uniquely ill temper that keeps SCUBA divers and snorkelers at a distance.

Forming part of the Balistidae family, the approximate 40 species of triggerfish have unique mating habits, impressive adaptability, and an anger problem that can be triggered at any moment.

Let’s explore these grumpy ocean fish together.

Taxonomy

• Domain: Eukaryota
• Kingdom: Animalia
• Phylum: Chordata
• Class: Actinopterygii
• Order: Tetraodontiformes
• Family: Balistidae

Appearance and Anatomy

Triggerfish have a narrow, oval-shaped body, giving them a compressed, somewhat flat appearance.

Depending on the species, triggerfish grow between 8-20 inches (20-50 cm) on average, but some species, such as the titan triggerfish and the stone triggerfish (the largest triggerfish species), can reach up to a meter.

They have large heads with small yet powerful teeth-filled mouths for breaking shells. 

One of the most striking aspects of triggerfish is their vibrant colors.

With scales colored with hues of blue, yellow, orange, green, and reddish tones and an array of colorful spots and stripes forming unique patterns, triggerfish are easy to identify and a treat to gaze upon.

Did you know that triggerfish can change their color?

Apart from their boastful color arry, triggerfish are most noted for their sharp, movable dorsal spine above the eyes.

This hinged spine can be erected into an upright position, or folded back into a groove to assist in smooth swimming.

It is also from this trigger-like fin that the triggerfish gets its name.

Habitat and Distribution

Triggerfish are remarkably adaptable and can be found in the Pacific Ocean, the Caribbean, the east coast of Africa, and most abundantly in the Indo-pacific region.

Furthermore, some species, such as the Gray triggerfish, can be found distributed along the western Atlantic coast from Nova Scotia to Bermuda and the Gulf of Mexico.

Most triggerfish can be found inhabiting shallow coastal waters, often spending their time in coral reefs that provide boulders and crevices in which they can hide.

That said, although most species of triggers reside in coastal regions, there are pelagic species, one of which is the oceanic triggerfish.

Feeding and Behavior

Triggerfish are omnivores and opportunistic feeders, meaning they have a wide variety of prey, and tend to forage on whatever becomes available.

Their sharp teeth and powerful jaws allow them to consume a wide range of prey, including small fish, crustaceans such as crabs, mollusks, and sea urchins, as well as plant material like plankton.

Triggers have a variety of foraging techniques, but perhaps one of the most notable is the creation of “foraging pits.” 

Using their large heads and powerful jaws, triggers move sand and rocks to uncover the prey that’s hidden beneath.

Not only does this allow triggerfish greater access to food, but it benefits the larger ecosystem by mixing and aerating the soil and revealing buried organisms.

Reproduction and Lifecycle

Triggerfish have an interesting courtship pattern and, similarly to clownfish, engage in biparental egg protection.

Spawning is usually timed in relation to the moon’s cycle and the changeover of the tides, but before this occurs, some interesting pre-spawning behaviors occur.

Male and female triggerfish will come together, touching each other and blowing on the sandy seabed.

Doing this simultaneously in the same spot creates a suitable nesting spot.

During this precourtship ritual, the male and female will touch each other’s abdomens together, as if spawning; however, actually spawning only takes place after this courtship.

Eggs are laid on the sandy bottom and protected by both parents.

The female will perform a task known as “tending,” where she will roll, fan, and blow air onto the eggs to provide them with oxygen.

Males don’t typically perform tending but will instead remain at a further distance, protecting their territory from intruders, which include other triggerfish, predators, and SCUBA divers alike.

The territory of triggerfish is cone-shaped and extends from the ocean floor, expanding as it reaches the ocean’s surface.

This means that if you find yourself in a triggerfish territory, by swimming up you may end yourself deeper in their territory.

Instead, the best way to remove yourself is by swimming out in a straight line.

Threats and Defense 

Triggerfish, along with many marine species, face several threats to their survival, some of which come from their natural predators but others from poor human interaction with the ocean and its resources.

Habitat destruction due to pollution and coastal development, climate change, overfishing, and illegal triggerfish trade for aquariums are a few examples of how human interaction threatens the triggerfish population.

As far as natural predators go, larger fish such as groupers, jacks, tuna, marlin, and sharks are their biggest threats.

To defend themselves from these predators, triggerfish have developed various strategies, the most notable being their trigger spine.

When threatened, triggerfish wedge themselves into tight spaces and lock themselves in by locking the movable fin on their head.

They are also known to use these fins to display aggression when protecting their territories.

Apart from their spine, triggerfish can change their color, and expand their size by inflating themselves with water and producing warning grunting sounds.

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