Common Name
Atlantic Assfish
Year Described
Günther, 1887
Identification
Dorsal Fin: 122-128
Anal Fin: 100-109
Pelvic Fin: 1
Pectoral Fin: 25-27
Caudal Fin: 8
Gill Rakers: 15-20 (long rakers on first arch)
Vertebrae: 12-14 (precaudal), 67-73 (total)
Oblique Scales: 15-20
Body elongate, compressed, and tapering strongly post-anus. Body depth 6-10% SL. Head large (HL 15-19.5% SL). Mouth inferior. Anterior nostril on snout, posterior between front nostril and eye. Eye small. Mouth large, extending well past orbit. Rear of maxilla expanded. Tooth patches present on dentary, vomer, and palatine. Basibranchial patch present. Teeth tiny and conical. Preopercle lacks spines. Opercular spine weak. Dorsal and anal fins continuous with tail. Dorsal fin origin between preopercle and pectoral base (predorsal length 13-19% SL). Anal fin base averages under the 24th dorsal fin ray. Dorsal fin slightly higher anteriorly. Caudal fin present but small. Pectoral fin moderate, at eye level, and fan-like. Pelvic fin origin anterior to preopercle and reaching anus. Body flabby and weakly muscled. Cycloid scales relatively large and cover head and body but are absent on jaw. Lateral line absent.
Color
Body light brown with a darker head and gut region.
Size
Maximum size to 242mm SL.
Habitat
Known from deep slope to abyssal depths over soft bottoms (1783-5605m).
Range
Known from the Bahamas and off NE South America. Also off W. Africa.
References
Nielsen J.G. & N.R. Merrett. 2000. Revision of the cosmopolitan deepsea genus Bassozetus (Pisces: Ophidiidae) with two new species. Galathea Rep 18:7–56, 1 pl.
Tomiyama, S., M. Takami, and A. Fukui. 2018. A new deepwater assfish, Bassozetus nielseni sp. nov.(Ophidiiformes: Ophidiidae), from the North Atlantic and West Indian oceans. Ichthyological Research, 65, 353-362.
Other Notes
Material from the Bahamas is slightly different in morphology and also caught at a much shallower depth than open Atlantic material (Nielsen & Merrett, 2000).