Description
Sebastes borealis
(Shortraker Rockfish)
(Other common names: Buoy Keg, Grouper)
Figure 32.3
DescriptionLength: 91-108 cm.
Mouth: large, terminal, directed upwards; lower jaw projecting; upper jaw extends beyond mid-orbit; large pores on lower jaw (Kramer and O'Connell, 1995).
Body: head spines moderate to weakly developed (coronal may be absent); spine on lower gill cover edge; flat interobital space; preopercular spines close together; caudal fin indented; single lateral line that slopes ventrally at the point above the anal opening, then is straight to the caudal peduncle; one or more spines on lower gill cover.
Color: pink with vertical red bands; fins red; pelvics and pectorals may be ridged with black; mouth and gill cavity red with black blotches (occasionally reversed); silver to grey peritoneum.
Depth: up to 305 m (possibly as deep as 875 m).
Habitat: large individuals are probably solitary and live on silt or cobble bottoms near boulders.
Season: ovoviparious; mating occurs in the fall with birthing in April.
Diet: crustaceans (e.g., euphasiids, shrimps); forage fish (e.g., herring).
Predators: not determined.
Distribution: northern California to Kamchatka.
Scale DescriptionRelative Scale Size: large.
Position of Scales on Body: 36 to 46 diagonal rows below lateral line canal (Hart, 1973).
Overall Shape: square to slightly rectangular with the anteriolateral corners somewhat protruding past the anterior field.
Focus and Circuli: the focus abuts the edge of the posterior field, along the edge of ctenii growth and is approximately one-fifth the total scale length from the outside edge of the posterior margin. The circuli are continuous between the lateral and anterior fields (except broken by radii). The circuli are tightly compact.
Radii: numbers are variable and not diagnostic. Present in the anterior field only. The outer edge of the anterior field is generally straight (the odd scale is slightly convex) and is slightly to moderately scalloped.
