David Hall / Giant dendronotid nudibranch (Dendronotus iris, left) approaching its prey, a Tube-dwelling anemone (Pachycerianthus fimbriatus, right) which emerges from its tube at night, Staples Island, Queen Char...

David Hall / Giant dendronotid nudibranch (Dendronotus iris, left) rearing up, preparing to pounce on its prey, a Tube-dwelling anemone (Pachycerianthus fimbriatus, right) which emerges from its tube at night, Sta...

David Hall / Giant dendronotid nudibranch (Dendronotus iris, left) lunging at its prey, a Tube-dwelling anemone (Pachycerianthus fimbriatus, right) which emerges from its tube at night, Staples Island, Queen Charl...

David Hall / Giant dendronotid nudibranch (Dendronotus iris, left) latching on to its prey, a Tube-dwelling anemone (Pachycerianthus fimbriatus, right) which has withdrawn into its buried tube, pulling the nudibra...

David Hall / Giant Pacific octopus (Enteroctopus dofleini) close up of eye and arm curled, Vernon Rock, Queen Charlotte Strait, British Columbia, Canada. September.

David Hall / Giant Pacific octopus (Enteroctopus dofleini) showing arms and suckers, Vernon Rock, Queen Charlotte Strait, British Columbia, Canada. September.

David Hall / Giant Pacific octopus (Enteroctopus dofleini) emerging from its den, siphon open, Browning Pass, Queen Charlotte Strait, British Columbia, Canada. September.

David Hall / Giant Pacific octopus (Enteroctopus dofleini) emerging from its den inside a rocky crevice. Sandford Reef, Barkley Sound, Vancouver Island, British Columbia, September.

David Hall / Giant Pacific octopus (Enteroctopus dolfeini) using its ability to change color and shape to blend in with its surroundings amongst red urchins and other echinoderms, Fantasy Island, Walker Group, Que...

David Hall / A Giant rock scallop (Crassadoma gigantea) encrusted with and surrounded by several other invertebrates, including White anemones (Metridium sp.), White mushroom ascidians (Distaplia sp.), Red soft co...

David Hall / Subtidal organisms found in the extreme tidal current that occur at Nakwakto Rapids, including Gooseneck barnacles (Pollicipes polymerus), mussels, kelp, red algae, coralline algae and calcareus tubew...

David Hall / Gooseneck barnacles (Pollicipes polymerus) found only at Nakwakto Rapids, which has one of the strongest tidal currents in the world. Also seen are Vancouver featherduster worms (Eudistylia vancouveri...