This rockhead camouflages well with the rock on the right.
“Chances are you’re not going to see one of these unless you’re really looking.”
That’s what Bryan Kent, senior biologist at the Vancouver Aquarium, says about the rockhead (Bothragonus swanii), a small fish that can be very hard to find. Yet, there are two behind the scenes currently – they were found during a recent collecting trip in the Ucluelet area of west Vancouver Island (rockheads can be found from Alaska to California).
The rockhead has a pit, or indentation, on the top of its head. It’s not known what it’s for, although the pit makes the fish’s head look somewhat like a barnacle shell, perhaps helping this small fish camouflage in rocky tidepools. The pink on this particular one also allows it to hide well since it looks like the coralline algae growing on the rock beside it. Not all rockheads are this colour though; others can be mostly white or bright orange.
Rockheads are a type of fish belonging to the poacher family called Agonidae. Fishes in this family tend to have rigid bodies and are more likely to crawl than swim. They live on the bottom of the ocean and don’t have swim bladders.
As with all the animals at the Aquarium, the two rockheads will be kept behind the scenes during their quarantine period. After that, the plan is to move them into one of the smaller exhibits in the Treasures of the B.C. Coast gallery. Then, it will be up to you to use those peepers to find them… if you can.
Written by Karen Horak, writer-editor, content and digital experience at the Vancouver Aquarium.