Morphology Data of Oncorhynchus nerka
Identification keys
Abnormalities
Main Ref. Hart, J.L., 1973
Appearance refers to
Bones in OsteoBase

Sex attributes

Specialized organs
Different appearance
Different colors
Remarks

Descriptive characteristics of juvenile and adult

Striking features none
Body shape lateral fusiform / normal
Cross section compressed
Dorsal head profile clearly convex
Type of eyes more or less normal
Type of mouth/snout more or less normal
Position of mouth terminal
Type of scales
Diagnosis

Both the sockeye and the kokanee are distinguished by the long, fine, serrated, closely spaced gill rakers on the first arch that number between 30 and 40, and by its lack of definite spot on the back and tail (Ref. 27547). Body fusiform, streamlined, laterally compressed, body depth moderate, slightly deeper in breeding males (Ref. 6885). Head bluntly pointed, conical, eye rather small, position variable with sex and condition; snout rather pointed (Ref. 6885). Lateral line straight (Ref. 27547). Pelvic fins with axillary process; caudal emarginate (Ref. 27547). Pre-spawning fish are dark steel blue to greenish blue on the head and back, silvery on the sides and white to silvery on the belly; no definite spots on the back, although some individuals may have dark speckling and irregular marks on the dorsal fin (Ref. 27547). At spawning, the head of the males becomes bright to olive green, with black on the snout and upper jaw; the adipose and anal fins turn red and the paired fins and tail generally become grayish to green or dark; females are generally less brilliantly colored than males (Ref. 27547). Various populations may show less brilliant colors, and a few turn dull green to yellowish, with little if any red (Ref. 27547).

Ease of Identification

Meristic characteristics of Oncorhynchus nerka

Lateral Lines Interrupted: No
Scales on lateral line
Pored lateral line scales 120 - 150
Scales in lateral series
Scale rows above lateral line
Scale rows below lateral line
Scales around caudal peduncle
Barbels 0
Gill clefts (sharks/rays only)
Gill rakers
on lower limb
on upper limb
total 28 - 40
Vertebrae
preanal
total 56 - 67

Fins

Dorsal fin(s)

Attributes no striking attributes
Fins number 1
Finlets No. Dorsal   0 - 0
Ventral  0 - 0
Spines total 0 - 0
Soft-rays total 11 - 16
Adipose fin present

Caudal fin

Attributes other (see remark); more or less normal

Anal fin(s)

Fins number 1
Spines total 0 - 0
Soft-rays total 13 - 18

Paired fins

Pectoral Attributes  more or less normal
Spines     0
Soft-rays   11 - 21
Pelvics Attributes  more or less normal
Position    abdominal  behind origin of D1
Spines     0
Soft-rays   9 - 11
Main Ref. (e.g. 9948)
Glossary ( e.g. cephalopods )
Entered by Garilao, Cristina V.
Modified by Garilao, Cristina V.
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