Hexigrammus Decagrammus

By Peter Mieras
Rendezvous Dive Adventures

One of the most often observed fish species is the kelp greenling (Hexagrammos decagrammus). The species is easily identified and even the difference between male and female are obvious. The male has a body colour between brown and purple with bluish spots bordered by doted dark lines. The female steals the show with her silver body with yellow fins and orange spots. She is often a favourite subject for underwater photographers. Their habitat ranges from rocky shores with sandy areas to reef pinnacles with boulders. In general you won’t find this fish deeper than 20 meters.

This fish can be observed all year round with there only being a few dives during which this fish is not seen. This abundance of observations make some divers reluctant to spend any time observing it. This is too bad as they are both curious and timid at the same time. Especially in the autumn and winter month this fish is especially worth paying some attention to. In late October/ early November a patient diver can see the courting behaviour between the males and the females. When they meet and decide to have offspring they perform what seems to be a courtship dance. The female undulates her body like a Lambada dancer to attract the male. It looks a bit like she is trying to swim but the movement does not advance her forward. The male(s) react to this invitation by first deciding who has the right to mate.

Males are frequently seen chasing each other away from where the female hangs out. After that the male joins the female in the dance and comes along side the female, swims away, and come back. It turn more into a tango experience of attraction and retreat. How a Canadian West Coast fish can be so “latino”.

After the courtship the female finds a suitable spot to lay her eggs. This usually happens from late November into January. The eggs are small and look like pearls with their mauve or bluish colour. Eggmasses are found in empty shells of the giant acorn barnacle, in the holdfasts of kelp or even in manmade structures such as wrecks, anchor chain, and anything that provides shelter and a good hold. The male subsequently fertilizes the eggs and guards them.

In the summer the now hatched juveniles can often already be distinguished into male and female. The juvenile female looks like a miniature version of the female but is entirely dark yellow. The juvenile male is red and already there are some small white spots present.

So next time you encounter this fish give it a little more time.

Acknowledgements: Jackie Hildering for suggestions and corrections.

Animal Facts:

Family:
Hexigrammus

Scientific Name:
Hexigrammus Decagrammus
 
Common name:
Kelp greenling

Description:
The female usually is silver with yellow/dark orange colours whilst the male is an even brown with bluish spots enclosed by a dark spotted border

Range:
Alaska to California

Size:
Up to 60 cm(24” long)

Hangouts/Habitat:
Mostly shallow areas with rocks and sand

Depth:
Intertidal to 27 meter

Behaviour:
Curious about divers and usually does not flee. In the mating season the males chase each other fiercely out of territories. The female solicits the male with a courting dance.

Reproduction:
Eggs fertilized and guarded by the male in winter

Biggest Enemy:
Other fish when they are in juvenile stage. Sea lions and seals in adult stage.

ID Clues:
Thread like projections on the head of the female behind the eyes.

Video at: www.youtube.com/watch?v=41BVMpcU53k