California spiny lobster

The California spiny lobster (Panulirus interruptus) is a species of spiny lobster found in the eastern Pacific Ocean from Monterey Bay, California to the Gulf of Tehuantepec, Mexico. It typically grows to a length of 30 cm (12 in) and is a reddish-brown color with stripes along the legs, and has a pair of enlarged antennae but no claws. The interrupted grooves across the tail are characteristic for the species. Females can carry up to 680,000 eggs, which hatch after 10 weeks into flat phyllosoma larvae. These feed on plankton before the metamorphosis into the juvenile state. Adults are nocturnal and migratory, living among rocks at depths of up to 65 m (213 ft), and feeding on sea urchins, clams, mussels and worms. The spiny lobster is eaten by various fish, octopuses and sea otters, but can defend itself with a loud noise produced by its antennae. The California spiny lobster is the subject of both commercial and recreational fishery in both Mexico and the United States, with sport fishermen using hoop nets and commercial fishermen using lobster traps. In common with all spiny lobsters, the California spiny lobster has two large, spiny antennae, but no large claws on its legs. The California spiny lobster is one of the largest spiny lobster species, and grows up to 60 centimeters (24 in) long, but does not usually exceed 30 cm (12 in). Males can weigh up to 7.4 kilograms (16 lb)., with the record being a 16 lbs., 1 oz. male caught off Catalina island in 1968. The upper side of the animal is brownish red, without the paler bands or spots seen in some other spiny lobsters. The legs are a similar color, but with one or more lighter streaks running along their length. Males and females of all ages can be distinguished by the position of the two round genital openings or gonopores. In females, they are at the bases of the third pair of pereiopods, while in males they are at the base of the fifth (last) pereiopods, furthest from the head and the closest to the abdomen. Mature females have a small claw on the fifth pereiopod, and enlarged pleopods. The California spiny lobster is found in parts of the Gulf of California, and along the Pacific coast of the length of the Baja California peninsula, extending as far north as San Luis Obispo Bay, California. There are occasional records from Monterey Bay, but the water there is too cold for the California spiny lobster to breed, and it is thought that any adult found in Central California arrived as a larva during El Niño years. California spiny lobsters live on rocky substrates, at depths of up to 65 meters (213 ft). Although adults can be found in shallow water, including tide pools, they are more frequent in deeper waters. Juveniles generally inhabit rocky habitats at a depth of 0–4 m (0–13 ft) with dense plant cover, especially the surf grass Phyllospadix torreyi. California spiny lobsters are nocturnal, hiding in crevices during the day, with only the tips of their long antennae showing, as a means of avoiding predators. Towards dawn, the spiny lobsters form aggregations, which they maintain until dusk. At night, they emerge and feed on sea urchins, clams, mussels and worms. This activity is important in limiting sea urchin populations, and so maintaining healthy seabed communities. Natural predators of the California spiny lobster include bony fish such as the California sheephead, giant sea bass and cabezone, sharks including the horn shark and leopard shark, octopuses and sea otters. In response to an approaching predator, spiny lobsters including the California spiny lobster can produce a loud noise using the stick-slip phenomenon, akin to a bowed instrument. The bases of the antennae act as a plectrum, which is rubbed over a file on the edge of the antennular plate. If a predator is very close, spiny lobsters will flex their muscular tail in order to escape the predator, backwards.