Striated frogfish

Lore & Background

The striated frogfish was first formally described in 1794 as Lophius striatus by the English biologist George Shaw, with its type locality given as Tahiti in the Society Islands. Within the genus Antennarius, this species belongs to the striatus species group. The genus name Antennarius alludes to its first dorsal spine being adapted into a tentacle on the snout used as a lure, while the specific name striatus refers to the numerous black streaks on its body.

This small fish grows up to 22 cm long. Its soft skin is covered with irregularly-arranged dermal spinules resembling hairs, and its large mouth is forwardly extensible, allowing it to swallow prey as large as itself. The coloring is extremely variable, ranging from yellow to brownish-orange, green, gray, brown, almost white, or completely black. Body and fins can be marked with roughly parallel dark stripes or elongated blotches. The first dorsal spine, the illicium, tips forward and has a worm-like esca (lure) that attracts prey. The illicium has the same length as the second dorsal spine and is often darkly banded. The pectoral fins are angled, and with the pelvic fins, allow the frogfish to 'walk' on the sea bottom.

The striated frogfish is found in tropical and subtropical waters from the Indian Ocean to the center of the Pacific Ocean, and in the Atlantic Ocean on the western coast of Africa and from the New Jersey coast to the southern Brazilian coast including the Gulf of Mexico and the Caribbean. It inhabits shallow, sandy areas or rocky and coral reefs to deep waters, often mimicking coral or sponges through cryptic coloration. Some researchers consider Antennarius striatus a species complex, and the putative synonym Antennarius scaber is apparently a distinct species.

Reader's Guide

The striated frogfish is a significant species within the family Antennariidae due to its distinctive hunting strategy and remarkable camouflage. As a voracious carnivore, it devours all right-sized prey that pass within reach, usually other fish, but sometimes even its own kind. It can swallow prey its own size. The fish uses its illicium and esca as a lure, waving it to attract unsuspecting prey, and can inhale its food in six thousandths of a second. It is one of the rare species of this family that exhibits a chemical attractant when fishing, mainly used at night.

The species has a benthic and solitary lifestyle, gathering only during mating. It uses a unique form of locomotion involving jet-like propulsion from water expelled through tube-like gill openings, as well as walking along the floor using its jointed pectoral and pelvic fins. Its defense mechanism includes swelling its body with water to make swallowing difficult. The frogfish also exhibits Batesian mimicry, mimicking dangerous species such as sea anemones or sea urchins to prevent predator attacks.

Rising ocean temperatures and acidification pose a threat to the frogfish's habitat, as coral bleaching reduces the environments it depends on for camouflage. The species can change coloration over a few weeks to adapt, but the loss of coral color may increase its vulnerability to predators.

Did You Know?

• The striated frogfish can swallow prey as large as itself.
• It can change coloration over a few weeks to match its environment.
• The esca (lure) is worm-like and is rolled up close to the body when not hunting.
• It is one of the rare frogfish species that uses a chemical attractant when fishing at night.

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