Chaunacidae

Introduction

The chaunacids are one of the more recognizable lophiiform families, with large globose heads, a conspicuous network of open sensory canals, and a single open lateral–line canal extending posteriorly along a moderately compressed trunk and tail. The angling apparatus consists of a short illicium with a terminal esca comprised of a dense cluster of short cirri. The family contains two genera and 15 species. Chaunacids live a benthic lifestyle at depths ranging from 90 to over 2000 m. Researchers at the College of Charleston recently captured a red-eyed gaper (Chaunax stigmaeus) on video sitting on the seafloor off South Carolina, U.S.A.

Chaunacids are occasionally caught as bycatch in commercial fishery operations; however, with the exception of some regions in eastern Asia, chaunacids are not marketed for human consumption.

Characteristics

Body rounded and very slightly compressed, with very loose, flaccid skin; body tapering to a small rounded tail. Head very large and globose, roughly cuboid and bearing especially prominent open lateral-line canals; eyes dorsolateral and covered with a clear ‘window’ of skin; mouth large, oblique to nearly vertical, with relatively small, sharp slender teeth. Illicium short, located just behind snout in front of an ovoid, scaleless patch of skin, or within a depression into which it can be retracted; esca mop-like, a dense cluster of numerous, short, thread-like cirri; two additional cephalic dorsal-fin spines present as embedded vestiges, postcephalic dorsal-fin spines absent; soft dorsal fin with 10 to 12 rays, anal fin with 5 to 7 rays, pectoral fins narrow and paddle-like, with 10 to 15 soft rays. Skin densely covered with small to minute spine-like scales that are somewhat similar both in shape and feel to placoid scales of some sharks. Single open lateral-line canal on body joining conspicuous canals on head and extending posteriorly to proximal portion of caudal fin; lateral line proper with 17 to 42 neuromasts (Caruso, 1989a, b).

Color generally pink, reddish, orange, or rose-colored; some species with pale diffuse spots of yellow or olive green.

Key to the Genera of the Chaunacidae

1A. Anal-fin rays 5 or 6 (usually 6); greatest distance between anterolateral angles of sphenotic bones (prominent bumps beneath skin behind eyes) 22 to 27% of standard length; 9 neuromasts in supraorbital row (A-B), 1 neuromast in upper preopercular row (B-C), 2 in lower preopercular row (C-D), 3 in pectoral row (D-E), 17 to 21 in lateral line (B-F) (Bathychaunax Caruso, 1989b)

1B. Anal-fin rays 6 or 7 (usually 7); greatest distance between anterolateral angles of sphenotic bones (prominent bumps beneath skin behind eyes) 15 to 23% of standard length; 10 to 13 neuromasts (usually 11) in supraorbital row (A-B), 2 to 4 neuromast in upper preopercular row (B-C), 3 to 5 in lower preopercular row (C-D), 10 to 13 in pectoral row (D-E), 29 to 42 in lateral line(E-F) (Chaunax Lowe, 1849)

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© 2005

References

Caruso, J. H. 1989a. Systematics and distribution of the Atlantic chaunacid anglerfishes (Pisces: Lophiiformes). Copeia, 1989(1):153-165.

Caruso, J. H. 1989b. A review of the Indo-Pacific members of the deep-water chaunacid anglerfish genus Bathychaunax, with the description of a new species from the eastern Indian Ocean (Pisces: Lophiiformes). Bull. Mar. Sci., 45(3):574-579.

Lowe, R. R. 1849. On a new genus of the family Lophiidae (les Pectorales P?dicul?es, Cuv.) discovered in Madeira. Trans. Zool. Soc. Lond., 3:339-344.