How to Identify Kelp Greenling

To identify Kelp Greenling (Hexagrammos decagrammus), look at these key features.

Physical Characteristics

Body shape

elongated

Coloration

Highly variable and sexually dimorphic. Males typically exhibit mottled brown, olive, or bluish-gray bodies with bright blue spots edged in reddish-brown on the head and anterior body. Females are generally more uniformly mottled brown, tan, or reddish-brown with small, dark spots or speckles. The ventral surface is usually lighter. Coloration is cryptic, adapting to the surrounding environment.

Scale type

ctenoid

Mouth position

terminal

Distinctive features

Five lateral lines on each side of the body (a key family characteristic, though not always easily visible in the field)., A single, deeply notched dorsal fin with 23-26 spines and 21-24 soft rays., Large, fan-like pectoral fins., A fleshy cirrus (small, fleshy flap) above each eye and another smaller one on the nape., Males possess distinct blue spots with reddish-brown margins on the head and forebody.

Dorsal fin

Single, long, deeply notched dorsal fin with 23-26 strong spines anteriorly and 21-24 soft rays posteriorly.

Tail fin

Truncate to slightly emarginate caudal fin.

Pectoral fin

Large, rounded, fan-like pectoral fins with 18-20 rays.

Distinctive fins

Pelvic fins are thoracic, located beneath the pectoral fins, with one spine and five soft rays. Anal fin has 23-25 soft rays, lacking spines.

Identification Tips

1. 1

   Lateral Lines

   Count the five lateral lines on each side. While sometimes faint, this is a definitive family characteristic for Hexagrammidae.

2. 2

   Coloration and Spots

   Observe the body coloration and presence of blue spots. Males have prominent blue spots with reddish-brown borders on the head and anterior body, which are absent in females. Females are generally more uniformly mottled brown/tan.

3. 3

   Fleshy Cirri

   Look for the fleshy cirrus above each eye and a smaller one on the nape. These are characteristic features.

4. 4

   Dorsal Fin

   Note the single, long, deeply notched dorsal fin, which is typical for greenlings.

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