Clown Triggerfish (Balistoides conspicillum)

To reproduce, these adorable fish dig a hole in the sand, lay eggs, and take turns guarding their nesting territory. Both the mom and dad will aggressively defend an inverted cone-shaped area above the eggs by chasing, biting, and generally attacking anything that swims too close.

Honeycomb Cowfish (Acanthostracion polygonia)

Like most members of the Ostraciidae family (also including boxfish and trunkfish), the honeycomb cowfish will secret a toxic mucus when it’s caught and handled. This can cause irritation if it comes into contact with the eyes and sensitive skin, or even kill all of the nearby fish in a net or aquarium.

Image Credit: Tim Dyes

A trunkfish can eat by spraying a jet of water through its mouth and snatching up any exposed invertebrates on the seafloor. They are omnivorous bottom feeders which eat a variety of mollusks, algae, sea cucumbers, marine plants, sponges, and small crustaceans.

Spotted Trunkfish (Lactophrys bicaudalis)

Trunkfish have a triangular, bony outer layer that serves as a sort of body armor and protects them from predators. Their shape and rigidity makes it awkward to swim, so they usually amble around in a slow hover by using the smaller fins for locomotion. (The tail fin kicks in when something requires a high speed getaway.)

Lionfish love to gorge themselves. Their bellies can expand up to 30x the original size, so there’s not much to stop a voracious appetite from devouring everything in its path. The fish has become an invasive species in the Atlantic, forcing Bermuda to adopt a spear-on-site policy to try and control the population. This cute little guy managed to survive his spearing and now lives domestically in our lab aquarium. (His name is Larry.)

Contrary to popular belief, moray eels are generally shy and NOT aggressive. They would rather hide in their burrows and sit and wait for some curious prey to stop by. Once a shadow appears in front of the hole, the eel will lunge out and snap-clamp its jaws onto it. They must rely on an acute sense of smell to make up for some pretty bad eyesight, so it’s hard for them to distinguish between a sliver of fish and a human finger.

Image Credit: Richard Ling