Spotfin frogfish

Lore & Background

The spotfin frogfish was first formally described as Chironectes nummifer by the French zoologist Georges Cuvier, with its type locality being unknown. The 5th edition of Fishes of the World classifies the genus Abantennarius in the family Antennariidae within the suborder Antennarioidei within the order Lophiiformes, the anglerfishes. The genus name Abantennarius prefixes ab, meaning 'away from', onto antennarius, a fish of the family Antennariidae, alluding to the gill opening being positioned away from the base of the pectoral fin. The specific name nummifer is a compound of nummis, meaning 'coin', and fero, meaning 'to bear', referring to the large brown spot on the second dorsal fin.

The spotfin frogfish has three dorsal spines and a second dorsal fin containing 12 or 13 soft rays, while the anal fin contains 7 or 8 soft rays. The iliicium is about the same length as the second dorsal spine and bears an esca that is bulb-shaped with filaments, resembling a fat shrimp. It has a caudal peduncle, and the rear of the dorsal and anal fins are connected to the outer rays of the caudal fin by a membrane. The skin has no scales but is densely covered with forked spinules. The pectoral fins are prehensile, have an elbow-like joint, and have the gill opening on or near their base. Overall colour may be yellow, rusty, pink, or red with a brown or reddish brown head, fading to brown or greenish brown on the body and fins, with a scattering of irregular greenish white blotches. The base of the second dorsal fin almost always has a dark spot surrounded by an indistinct greenish ring.

The spotfin frogfish is associated with reefs and is found as deep as 293 m (961 ft), though typically at depths of less than 20 m (66 ft), with Atlantic populations in deeper waters than those in the Pacific. It can be found in the intertidal zone on reefs in lagoons and on seaward reefs.

Reader's Guide

The spotfin frogfish is notable for its wide distribution across the eastern Atlantic, Indian, and western Pacific Oceans, recorded from locations such as the Azores, Madeira, the Canary Islands, Saint Helena, the Red Sea, South Africa, Madagascar, the Mascarenes, Seychelles, Maldives, the Persian Gulf, the Society Islands, Hawaiian Islands, Australia, northern New Zealand, and Japan. Its taxonomy places it within the family Antennariidae, order Lophiiformes, as classified in the 5th edition of Fishes of the World. The species is oviparous, with females laying egg masses within ribbons of gelatinous mucus known as 'egg rafts' or 'veils'; one captive-laid raft was estimated to hold 48,000 eggs. The larvae are planktonic and settle onto the reef after one or two months. It is piscivorous, attracting prey with its shrimp-like esca. The species reaches a maximum total length of 13 cm (5.1 in).

Did You Know?

• The spotfin frogfish is also known as the coin-bearing frogfish due to the large brown spot on its second dorsal fin.
• Its esca (lure) is bulb-shaped with filaments and resembles a fat shrimp.
• The species has been recorded at depths up to 293 m (961 ft), though typically found shallower than 20 m (66 ft).
• A single egg raft laid in captivity was estimated to contain 48,000 eggs.