Bottomfish
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Bottomfish Identification: Rockfish

Splitnose Rockfish
Sebastes diploproa

Occasionally caught off the Washington coast by commercial harvesters using otter-trawls and longline gear.  Recreational harvest within Puget Sound has been closed.  See the Sportfishing Regulation Pamphlet.

Description: Splitnose rockfish are a deep-bodied, relatively small species with many sharp head spines and large eyes.  The upper jaw is split with a toothed knob on either side.  Underwater, adults are pale pink, light orange or white with darker pink, orange or red patches or bars on the dorsal surface, head and fins. After capture dorsal and side colors change to a uniform red or dark pink, while the belly remains pale.  The dorsal fin spines may have white tips and the membranes between each spine may be dark fringed.  Adult splitnose resemble the aurora and chameleon rockfishes but splitnose have a distinct, deep notch between the upper jaws (i.e., on their nose) and large eyes.

Maximum Size: To 46 cm (18.4 in) in length, and 180 g (0.4 lbs) in weight.

Maximum Age: At least 86 years old.

Range/Habitat: Splitnose rockfish range from the Alaska Peninsula and Prince William Sound, Alaska, to Cedros Island, Baja California. Adults are found at water depths from 91 to 795 m (299-2,622 ft).  They are most common at depths from 215 to 350 m (705-1,155 ft).  Pelagic juveniles up to 1 year old have been found among drifting vegetation in Puget Sound.  Adults are benthic and commonly occur on low-relief mud fields of the continental shelf and upper slope.  They have been found in the Hood Canal on mud and gravely deep sea mounds. While solitary animals are often seen resting on the seafloor, this species also forms schools off the bottom.

Sources:

  • Love, M. S., M. Yoklavich, and L. Thorsteinson, 2002. The rockfishes of the northeast Pacific. University of California Press.
  • Washington Division of Geology and Earth Resources. Open File Report 2012-01, Nov. 2012.
  • http://www.fishbase.us/summary/Sebastes-diploproa.html

Photo:  WDFW and A. Hennings