(Randall, 1840)
Diagnosis:
Antennular plate with 4 large, widely separated spines arranged in a square. Exopodite of third maxilliped present, with flagellum. Transverse groove of abdominal somites with straight margins, not crenulated. Transverse grooves of abdominal somites wide, abruptly interrupted in middle.
Colour: body and abdomen dorsally rather uniformly brownish red, without light bands or spots. Legs brownish red with one or more pale longitudinal streaks.
Type:
Type locality: "from Upper California, where it is used as food by the natives". T. Nuttall, who collected the type material visited Monterey, Santa Barbara, San Pedro and San Diego in California (March - May 1836); he was most active in Santa Barbara and San Diego, and one of these two localities in all probability is the true type locality. Two dry syntypes in ANSP, No. 4188 (condition poor to reasonable).
Geographical Distribution:
Eastern Pacific region: California, USA (from San Luis Obispo Bay southwards; there is a doubtful record from Monterey), to Baja California, Mexico (entire west coast); the species is also reported from the Gulf of California.
Habitat and Biology:
From the littoral zone (tide pools) to depths of about 65 m, being more frequent in the deeper waters; on rocky substrates. The species is nocturnal; spawning takes place from May to August.
Size:
The maximum total body length reported is 60 cm, usually it does not exceed 30 cm. The legal size limit is a carapace length of 3.25 inch ( = 8 cm), corresponding to a total length of about 20 cm.
Interest to Fisheries:
Panulirus interruptus is the economically most important lobster of the American west coast. In California it is taken almost exclusively with traps, also trammel nets are used, and occasionally they are obtained by trawling The species is also taken by diving by sports fishermen; according to Frey (1971) "the sport catch... may equal 50 % of the commercial catch". The total catches in 1976 were about 135 tons. The major fishing area is the west coast of Baja California.
The demand for the lobster in California '"is so great that imports from Mexico average about twice the California catch" (Frey, 1971); of course the imported lobsters do not all need to be P. interruptus. Protective measures as to season, size, bag limit, etc. are at present in force. Sold fresh, cooked and frozen. Best known as gourmet food, sometimes used as bait.