Male kelp greenling. Normal colouration. © 2006 Jackie Hildering

While diving this morning, I came across a kelp greenling couple while they were courting (Hexagrammos decagrammus).

In addition to being fascinated by the courtship behaviour, I was struck by the intense colouration, especially of the courting male.

Mature male and female kelp greenlings look very different but I had never fully realized how the males’ gender specific colour intensifies during courtship. Their bodies become much paler while the heads remain dark blue.

Courting male on left (note how much lighter the body is than the head); female on the right. © 2013 Jackie Hildering

Courting male on left (note how much lighter the body is than the head); female on the right. © 2013 Jackie Hildering

This 1.5 minute video shows the courtship behaviour. See below for an image of eyed kelp greenling eggs.

Kelp greenling eggs in a giant barnacle shell. See the eyes?! © 2013 Jackie Hildering

Kelp greenling eggs in a giant barnacle shell. See the eyes?! © 2013 Jackie Hildering