Chaunacidae

Introduction

The chaunacids are one of the more recognizable lophiiforms families, with large globose heads and 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 s short illicium, with a terminal esca comprised of a dense cluster of short cirri. The family contains two genera and 15 species. Chanaucids 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 tapers to 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, or 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, and postcephalic dorsal-fin spines absent; soft dorsal find 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 joins conspicuous canals on head and extends 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 Lophidae (les Pectorales P?dicul?es, Cuv.) discovered in Madeira. Trans. Zool. Soc. Lond. 3:339-344.