California Spiny Lobster, Panulirus interruptus
California Spiny Lobster, Panulirus interruptus. Lobster courtesy of the commercial fishermen of the greater Los Cabos area, Baja California Sur, December 2012. Size: 30 cm (11.8 inches).
Phylogeny: The California Spiny Lobster, Panulirus interruptus (Randall, 1840), is a member of the Palinuridae Family of Spiny Lobsters. The Panulirus Genus is one of twelve genera in the Palinuridae Family, and there are twenty-two species in the Panulirus Genus. The genus name Panulirus is New Latin term that comes from an anagram of the name Palinurus. Palinurus was a helmsman in Roman mythology. This refers to the habit of lobsters in this genus migrating back and forth between the coast and deeper water. The species name interruptus is Latin, meaning “broken off”. This refers to the interrupted grooves on the abdominal segments. They are known in Mexico as Langosta Californiana and Langosta Colorada.
Morphology: California Spiny Lobsters are reddish-brown in color with a lighter stripe running the length of each leg. The carapace has two dark eyespots at the front. They have a pair of enlarged spiny antennae and interrupted grooves across the tail which are unique to this species. They lack claws but have very strong mandibles that are used for crushing shells. The spines of the California Spiny Lobster are not as sharp as those of more tropical species, but their spines and horns over the eyes are easily capable of puncturing human skin. California Spiny Lobsters can reach 70 cm (2 feet 4 inches) in length and 12 kg (26 lbs.) in weight, but are normally half that size. They are sexually dimorphic with males being larger than females. Males can be distinguished from females by the position of two round genital openings (gonopores); in females the gonopores are at the base of the third pair of pereiopods and in males they are at the base of the fifth pair.
Habitat and Distribution: California Spiny Lobsters shelter in rocky reefs during daylight hours. They’re often found in groups of a dozen, or more, individuals. They are found from the lower intertidal zone to depths up to 76 m (250 feet). They undergo an annual migration to shallow water in the spring and return to deeper waters in the winter. California Spiny Lobsters are a subtropical to tropical Eastern Pacific species with a limited limited distribution in Mexican waters of the Pacific Ocean found from Magdalena Bay, Baja California Sur, nortward along the central and northwest coasts of the Baja Peninsula. There are also found in small pockets in the extreme southern Sea of Cortez, including the Los Frailes and Cabo San Lucas regions of Baja California Sur.
Diet: The California Spiny Lobster is omnivorous and emerges at night to feed on algae, clams, detritus, mussels, urchins, and worms.
Predators: California Spiny Lobsters are preyed upon by California Sheephead, Cabezon, Calico Bass, Giant Sea Bass, Horn Sharks, Leopard Sharks, various moray eels and rockfishes as-well-as Octopuses and Sea Otters. They utilize their ability to make a loud rasping sound with their antennae and their ability to quickly retreat backwards as defense mechanisms
Reproduction: The California Spiny Lobster is gonochoric (male or female for life) and reproduce sexually with external fertilization. Males attach a spermatophore onto the sternum of the female. Then, the female moves into shallow water and extrudes approximately 50,000 to 80,000 eggs, which are then fertilized by sperm from the spermatophore. Masses of these fertilized eggs attach to the pleopods of the females. The eggs hatch into a planktonic phyllosoma larvae. This larvae will molt ten times over the next seven months before settling to the bottom. California Spiny Lobsters grow by periodically molting their exoskeleton, and lost appendages can be replaced at this time. They reach maturity at about five years of age and they have life spans of between thirty and fifty years.
Ecosystem Interactions: The California Spiny Lobster plays an important role in the ecosystem limiting sea urchin populations, thus protecting kelp forests. They are known to host various bacteria, viruses, and protozoans as endoparasites. They host, barnacles, hydroids, nemerteans, sponges, and serpulid worms as ectobionts.
Human Interactions: The California Spiny Lobster is fished extensively by commercial fishermen as they are considered to be an excellent human food. At present they are the most economically important lobster on the West Coast with about half the catch being made by recreational sportfishermen (250,000 kg or 560,000 lbs. per year) with hoop nets and the other half made by commercial fishermen with lobster traps. They are heavily regulated in both California and Mexico with restrictions on gear employed, fishing seasons, and size and bag limits. They represent the fifth most valuable fishery in Mexico with sales at a level of $18,000,000 (800 tons) annually. From a conservation perspective, the California Spiny Lobster is considered a species of Least Concern.
Synonym: Palinurus interruptus.