Fowlerichthys radiosus
A Western Atlantic frogfish with a single large ocellus.
**Fowlerichthys radiosus**, also called the singlespot frogfish or big-eyed frogfish, is a marine ray-finned fish in the family Antennariidae. It lives in the Western Atlantic Ocean.
The species was first described in 1869 by American zoologist Samuel Garman as *Antennarius radiosus*, with the type location off Key West, Florida. In 1941, Thomas Barbour described a new species, *Fowlerichthys floridanus*, from off Palm Beach, Florida, placing it in a new genus, *Fowlerichthys*, and making it the type species. Today, *F. floridanus* is considered a junior synonym of *Antennarius radiosus*. The 5th edition of *Fishes of the World* places the genus *Fowlerichthys* in the family Antennariidae, suborder Antennarioidei, order Lophiiformes (the anglerfishes).
The genus name *Fowlerichthys* honors American ichthyologist Henry Weed Fowler, who gave Barbour the type specimen of *F. floridanus*, combined with *ichthys* (Greek for fish). The specific name *radiosus* means "rayed," referring to the illicium (first dorsal spine) being twice as long as that of the presumed relative *Antennarius tigris*.
The body is somewhat compressed and globose, with large eyes on the sides of the head and a large, upward-pointing mouth lined with many small teeth. The small gill openings sit behind and below the base of the pectoral fin, which is limb-like with an elbow-like joint and a broad connection to the body. There are three dorsal spines; the first (the illicium) is about as long as the second and topped with a small, folded oval esca. The second dorsal spine is not very curved and is connected to the head skin by a membrane. The third dorsal spine is movable and not connected to the head skin. The dorsal fin has 13 soft rays, and the anal fin has 9 soft rays. There is a caudal peduncle, and the rear edges of the dorsal and anal fins are not connected to the caudal fin. The skin is densely covered with bifurcated spicules. Coloration ranges from brown to beige, with the anal, caudal, and dorsal fins sometimes barred. The illicium usually has pale bands. A single large ocellus appears on the upper body and the base of the dorsal fin, and short dark lines radiate from the eye. FishBase gives the maximum published standard length as 9.4 cm (3.7 in), while the Smithsonian Tropical Research Institute reports a maximum length of 25 cm (9.8 in).
Quick Facts
- Taxon
- Fowlerichthys radiosus
Facts from the source article.
Lore & Background
Fowlerichthys radiosus was first formally described as Antennarius radiosus in 1869 by American zoologist Samuel Garman, with its type locality given as off Key West, Florida. In 1941, Thomas Barbour described a new species, Fowlerichthys floridanus, from off Palm Beach, Florida, placing it in a new genus Fowlerichthys and designating F. floridanus as its type species. F. floridanus is now considered a junior synonym of Antennarius radiosus. The 5th edition of Fishes of the World classifies the genus Fowlerichthys in the family Antennariidae within the suborder Antennarioidei of the order Lophiiformes, the anglerfishes.
The species has a somewhat compressed, globose body with large eyes on the sides of the head and a large upwardly pointing mouth with many small teeth. The first dorsal spine (illicium) is roughly equal in length to the second dorsal spine and topped with a small folded oval esca. The skin is densely covered with bifurcated spicules. Its color is brown to beige, with the anal, caudal, and dorsal fins sometimes barred; the illicium is normally marked with pale bands. A single large ocellus appears on the upper body and base of the dorsal fin, and short dark lines radiate from the eye.
Reader's Guide
Fowlerichthys radiosus is an aggressive, piscivorous predator that is otherwise rather sedentary when not hunting. Its reproductive biology includes ovaries resembling tightly wound double scrolls, and eggs are laid encased in a gelatinous mass that floats. The prejuveniles pass through a developmental stage called the 'scutatus stage,' in which bony plates extend backward from the cranium past the level of the opercular bones. The species is found in the Western Atlantic from Long Island, New York, south to Cuba and the Gulf of Mexico, and along the northern South American coast between Colombia and Surinam, with a reported occurrence from Madeira in the eastern Atlantic. It inhabits depths between 20 and 275 m on offshore banks and the deeper waters of the continental shelf. The genus name Fowlerichthys honors American ichthyologist Henry Weed Fowler, who gave Barbour the type specimen of the type species, F. floridanus; the specific name radiosus means 'rayed,' referring to the illicium being twice as long as that of its presumed congener Antennarius tigris.
Did You Know?
- The species was first described as Antennarius radiosus by Samuel Garman in 1869.
- Its type locality is off Key West, Florida.
- The maximum length is given as 9.4 cm by Fishbase and 25 cm by the Smithsonian Tropical Research Institute.
- Prejuveniles go through a 'scutatus stage' with bony plates extending backward from the cranium.
Frequently Asked Questions
Who is Fowlerichthys radiosus?
Fowlerichthys radiosus is a small marine ray-finned fish in the frogfish family Antennariidae, commonly known as the singlespot or big-eyed frogfish. It is native to the Western Atlantic Ocean and is easily recognized by its single prominent eye-spot marking.
What are Fowlerichthys radiosus's powers or role in its habitat?
As a frogfish, it relies on its single large ocellus as a key visual feature in its underwater surroundings. It inhabits a broad depth range of roughly 20 to 275 meters in the Western Atlantic, giving it flexibility across different water-column zones.
Why is Fowlerichthys radiosus important to fish taxonomy?
It was formally described in 1869 by American zoologist Samuel Garman based on a type specimen collected off Key West, Florida, making it one of the earlier-recognized frogfish species. Its later taxonomic history also shaped how the now-invalid genus Fowlerichthys was resolved.
What are Fowlerichthys radiosus's key physical traits and size?
The species has 13 soft dorsal rays, and its maximum standard length is recorded at about 9.4 cm in FishBase, while the Smithsonian Tropical Research Institute reports a maximum of 25 cm. Its most distinctive feature is the single large ocellus that gives it both the 'singlespot' and 'big-eyed' common names.
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