The California spiny lobster is a large ten-legged crustacean that is reddish orange in color. Spines cover their hard outer shell, known as the exoskeleton. This shell does not grow with the lobster, so as the crustacean gets larger, the shell must be shed periodically. This process of shedding is known as molting. After a spiny lobster molts, it usually remains hidden for a few days so as to allow the new shell to harden for protection. Unlike the American lobster, spiny lobster do not have large claws. Instead, this species of lobster has two long antennae, that are covered with sensory hairs, extending from the front of their body. The lifespan of spiny lobsters can be difficult to determine because the species molts. It is thought that they can live for as long as 30 years, but as a species that is highly targeted by fishermen, most California spiny lobsters usually do not live longer than five to seven years. They have been known to achieve lengths of over three feet and can weigh upwards of 16 pounds.
Spawning occurs once a year during late spring through the summer. Male lobsters attach a sperm packet (called a spermatophore) onto the underside of the female lobster’s carapace. Females produce 50,000 to 800,000 eggs depending on their size and the eggs are carried on the underside of her tail. The eggs are fertilized when the female opens up the spermatophore using a small claw located at the end of each last pair of walking legs. Fertilized eggs remain attached to the female’s tail until they hatch around 10 weeks later.
Once a lobster hatches, it passes through 11 larval stages known as phyllosoma, which have small, transparent, flattened bodies and spider-like legs. Phyllosoma drift along with the currents, feeding on other planktonic animals. This stage can last for up to 10 months and phyllosoma have been found at the surface of the ocean to depths of over 400 feet. In its final stage, the larvae develop into what looks like a transparent, miniature adult lobster with very long antennae. After spending much of its early existence drifting offshore, these late stage larvae which can now swim head towards coastal shallow waters. They settle in rocky, plant-dominated habitats along the coast where they will spend the rest of their lives.
Spiny lobsters are omnivores. Adults primarily eat crustaceans, mollusks, algae, and vegetal material. As predators, lobsters can play an important role in maintaining the diversity of both intertidal and subtidal communities. Predation on kelp-eating species such as sea urchins helps to maintain a balance in kelp forest ecosystems, providing a more stable habitat for other species that rely on the kelp for food and shelter. Lobster are prey for a variety of species including fish, octopus, eels, and sharks.