California sea cucumber

The California sea cucumber (Apostichopus californicus), sometimes called the giant California sea cucumber, ranges from the Gulf of Alaska down to Baja California. It lives from the low intertidal zone down to 250 meters (820 feet) deep, and is most common where currents are moderate and the seafloor is made of cobbles, boulders, or bedrock. People harvest it through small-scale artisanal fishing.

This sea cucumber can reach 50 centimeters (1 foot 8 inches) long and 5 centimeters (2 inches) wide. Its body is soft and cylindrical, covered in leathery skin that ranges from reddish-brown to yellowish. Just beneath the skin lies an endoskeleton.

The mouth and anus sit at opposite ends of the body. Around the mouth are twenty retractable tentacles used to gather food. Five rows of tube feet run from the mouth to the anus, and those on the underside help it cling to rocks.

It is a scavenger, feeding on organic matter by sifting through sediment with its tentacles or by positioning itself in a current to catch drifting food. It can live up to ten years.

A. californicus is solitary and active at night. When threatened, it may eviscerate—expelling its internal organs through the anus—or release sticky filaments to entangle or confuse predators.

The sexes are separate, and fertilization occurs externally. Spawning typically happens in August, with each female releasing thousands of eggs. After fertilization, a larva develops and metamorphoses into a sea cucumber within a few weeks.