Macropinna microstoma Chapman, 1939
Barreleye
Macropinna microstoma
photo by MBARI

Family:  Opisthoproctidae (Barreleyes or spookfishes)
Max. size:  15 cm TL (male/unsexed)
Environment:  bathypelagic; marine; depth range 16 - 1267 m
Distribution:  North Pacific: Bering Sea to Japan, and Baja California, Mexico.
Diagnosis:  Dorsal spines (total): 0-0; Dorsal soft rays (total): 11-11; Anal spines: 0-0; Anal soft rays: 14-14. This species' most striking feature is the transparent, cowl-like shield that covers the top of the head, and its prominent tubular eyes within. The shield is a tough, flexible integument that attaches to the dorsal and medial scales behind the head, and to the broad, transparent subocular bones that protect the eyes laterally. The fluid-field chamber found beneath the shield surrounds and protects the eyes with vivid green lenses. The tubular eyes of this fish can look forward as well as upward (with maximum arc of rotation observed about 75 degrees). The morphology of the eyes apparently allow at least two feeding modes: (1) with body horizontal and with eyes directed upward, it can spot food against lighted waters above, it pivots its body to bring the mouth up for ingestion while eyes are locked on target, rotating from dorsal to rostral relative to the body; and (2) with body horizontal, eyes rotate dorsal to rostral while tracking the path of descending food until it reaches the level of the mouth (Ref. 87379). Adipose at the base of the caudal peduncle (Ref. 6885). Adults dark brown (Ref. 6885).
Biology:  A solitary fish, occurring at lower mesopelagic depths beneath temperate and subarctic waters. Caught by midwater trawl nets in areas with bottom depths of 1600-3600 m. Stomach contents include cnidarian remains, however, its visceral anatomy suggests diets of mixed zooplankton, including both gelatinous and crustacean prey and siphonophore tentacles and nematocysts (Ref. 87379). Uncommon species (Ref. 6885). Oviparous, with planktonic larvae (Ref. 35626). A photo of a 15 cm long fish shown at http://www.newscientist.com/gallery/new-species/9.
IUCN Red List Status: Not Evaluated (N.E.) Ref. (130435)
Threat to humans:  harmless


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