Dive Dry with Dr. Bill

014: California Spiny Lobster

Tis the season... no, Santa Claus isn't on his way yet with lots of toys and goodies. The season I'm referring to is lobster season. The sport season began September 28th and the commercial season October 2nd.

The California spiny lobster lacks the tasty claws of its distant Maine relative. Our species is found from San Luis Obispo to Rosalia Bay, Baja California. It is nocturnal and comes out to forage at night on sea urchins, clams, mussels, worms and scavenge on dead animals. During the day they are generally seen hidden in rocky crevices with their long antennae sticking out. These antennae are used to fend off potential predators like octopus, sheephead, lingcod, cabezon, kelp bass, and moray eels, although they are probably not very effective against horn sharks, leopard sharks, giant sea bass, sea lions and divers. Lobster also use a quick flipping of the tail to propel themselves away from potential predators including divers. The scientific name (Panulirus interruptus) translates roughly as "sporadic backward tail."

The lobster's eyes are located on stalks and are protected by two sharp spines. The eyes are compound, like those of honey bees, and allow the lobster to more easily detect motion. Two smaller antenna-like structures in front known as antennules are used to detect motion as well as odors. The mouthparts consist of six pairs of structures with specialized functions. There are five pairs of walking legs and many pairs of small swimmerets along the underside of the tail.

Like other arthropods lobster have an external calcareous skeleton which must be shed or molted once or twice a year as the lobster grows. It takes five to six years for a lobster to reach legal size. The largest spiny lobster weighed more than 26 pounds and was 3 feet long, although such giants are rarely seen today. Spiny lobsters are said to live as long as 50 to 100 years, although most probably live no more than eight years.

Lobster mate in spring and summer. The male transfers a packet of sperm to the female, placing it between the last pair of legs. The sperm pack is said to resemble old chewing gum (Wrigley's off Catalina I'm sure!). The eggs are extruded by the female and are attached to hairs on the swimmerets under the tail. A female carrying eggs is said to be "in berry." Here as many as 75,000 eggs may be protected until they hatch into larvae known as phyllosomes. In the female the last pair of legs have claw-like structures that are used to tend the eggs.

The larvae may drift in the plankton for as long as 22 months and be dispersed significant distances. The larvae eventually settle out of the plankton and begin their life on the bottom. Although adult California spiny lobster may remain in one area for most of their lives, they have been found nearly 90 miles away from previously recorded positions. Smaller scale movements between shallow and deeper water are more common.

Now, I haven't taken a "bug" myself since about 1975 but as long as they're taken properly I have no problems with others doing so! To be taken legally by divers with a sport fishing license, lobster must be taken by hand (spears are not permitted). The lobster must have a carapace at least 3.25" long. No female lobster in berry may be taken. The commercial harvest of lobster in California is about 900,000 pounds. I wonder how much butter that requires?

© 2003 Dr. Bill Bushing. Watch the "Dive Dry with Dr. Bill" underwater videos on Catalina Cable TV channel 49, 10:00 AM and 5:00 PM weekdays.

Image caption: California spiny lobster in the Casino Dive Park and Lover's Cove

This document maintained by Dr. Bill Bushing.
Material © 2003 Star Thrower Educational Multimedia