PHOTO: Hungry Red Octopus Tries to Catch Crab at Linda Mar Beach

Pacifica resident Lincoln Allen snapped this photo of an “unexpected passenger” that attached itself to a crab cage of a kayaker crabbing off shore at Linda Mar Beach this week.

At first he couldn't tell what it was when he saw the cage with the octopus attached to it, the kayaker told a crowd forming on the beach. But when he realized it was an octopus, he reached down and pulled it to the surface and into his kayak.

“He said in his many years of crabbing here that this was only the second time he had surfaced an octopus,” said Allen.

Octopuses are mollusks without shells. A red octopus’s normal color is red or reddish brown, but like other octopuses it can change quickly — in a fraction of a second — to yellow, brown, white, red or a variety of mottled colors, according to information on the Monterey Bay Aquarium website.

An octopus usually forages at night, collecting several specimens — most commonly crabs, clams, and other mussels — before retreating to its den, where it eats at leisure. But since crabs are an octopus’s favorite food, according to the Monterey Bay Aquarium, perhaps this one couldn’t resist trying for a bite during the day. The octopus kills its prey with venom secreted from its salivary glands, then cracks the shell with its sharp beak.

Researchers consider octopuses to be the most intelligent invertebrates — maybe as intelligent as a house cat. The Monterey Bay Aquarium recommends not touching red octopuses since they have sharp beaks and are inclined to bite and then spit venom on the wound. Healing from an octopus bite might take three weeks.

The kayaker released the octopus back into the ocean after a few minutes of marveling at such a rare find.