Nudiantennarius subteres

Appearance

"Nudiantennarius" is distinguished from other frogfishes by the reduced number of spinules in the skin, the skin has only a partial covering of bifurcate dermal spinules, so few that the body has the appearance of being naked. The spinules are each no longer than the distance between their tips. The first dorsal spine, or illicium, has a distinct esca, or lure, and is naked without spinules. The illicium is around half the length of the second dorsal spine which is unusually long in comparison to other frogfishes, slender and is not connected to the skin of the head by a posterior membrane. The lobe of the pectoral fin is thin and is somewhat separated from the sides. This species has a caudal peduncle and the rear margins of the dorsal and anal fins are clearly attached to the just in front of the outer rays of the caudal fin. The dorsal fin has 12 soft rays while the anal fin has 7. There is typically at least one large ocellus on the base of the dorsal fin. The esca is small and round, has short filaments and fits in a thin groove beside the second dorsal spine. The deepwater frogfish has a maximum published standard length of 7.5 cm.

Naming

"Nudiantennarius" is a combination of "nudus", meaning "nude" or "naked", with the genus name "Antennarius", the type genus of the frogfish family, Antennariidae. This is a references to the seemingly naked skin, it only has a scattering of small denticles embedded in the skin on the head and body. The specific name, "subteres", prefixes "teres", which means "cylindrical" or "tapering", as in the English word terete, with "sub", meaning "less than". The authors did not explain what this was referring to but it is thought to be alluding to the shape of the body.

Distribution

"Nudiantennarius" is found in the Western Pacific Ocean in the Philippines and Indonesia, and off Japan. This species is usually encountered on substrates of brown or black sand, silt or mud, where there may be some soft coral, gorgonians and sponges but where there is very little hard coral. The deepwater frogfish has also been found on pier pilings and rarely among small patches of seaweed. Other records have come from areas dominated by leaf litter and refuse, particularly in areas near human habitation. Others have been recorded in habitats mainly made up of very coarse sand or fine coral rubble, with a few hard corals and gorgonians. In this habitat there were many small cephalopods, numerous decapods and other crustaceans, and a variety of fishes, largely juveniles such as small species of shark, burrowing snake eels, "Rhinopias eschmeyeri" and R. frondosa, as well as a number of other species of scorpionfishes and waspfishes. At another site this species and the striated frogfish.

Behavior

Nudiantennarius is most commonly observed on night dives off Bali. Dark coloured fishes are most numerous on coarse sand or gravel, frequently where there are patches of green algae, at depths between 4 and 20 m whereas the lighter and more colourful individuals are typically found in association with small sponges, similar in colour to the frogfish, at rather greater depths, between 12 and 30 m. This is an oviparous species.

Habitat

"Nudiantennarius" is found in the Western Pacific Ocean in the Philippines and Indonesia, and off Japan. This species is usually encountered on substrates of brown or black sand, silt or mud, where there may be some soft coral, gorgonians and sponges but where there is very little hard coral. The deepwater frogfish has also been found on pier pilings and rarely among small patches of seaweed. Other records have come from areas dominated by leaf litter and refuse, particularly in areas near human habitation. Others have been recorded in habitats mainly made up of very coarse sand or fine coral rubble, with a few hard corals and gorgonians. In this habitat there were many small cephalopods, numerous decapods and other crustaceans, and a variety of fishes, largely juveniles such as small species of shark, burrowing snake eels, "Rhinopias eschmeyeri" and R. frondosa, as well as a number of other species of scorpionfishes and waspfishes. At another site this species and the striated frogfish.