''Sicyonia ingentis'' is a species of

prawn Prawn is a common name for small aquatic crustaceans with an exoskeleton An exoskeleton () . is a skeleton that is on the exterior of an animal in the form of hardened integument, which both supports the body's shape and protects the intern ...

in the family Sicyoniidae known by the common name ridgeback prawn. It is native to the eastern

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five Borders of the oceans, oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is ...

, where it occurs along the coast of

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

and

Baja California Baja California, officially the Free and Sovereign State of Baja California, is a state in Mexico. It is the northwesternmost of the 32 federal entities of Mexico. Before becoming a state in 1952, the area was known as the North Territory of B ...

, its distribution extending from

Monterey Bay Monterey Bay is a bay of the Pacific Ocean located on the coast of the U.S. state of California, south of the San Francisco Bay Area. San Francisco itself is further north along the coast, by about 75 miles (120 km), accessible via California S ...

to Isla María Madre off

Nayarit Nayarit, officially the Free and Sovereign State of Nayarit, is one of the 31 states that, along with Mexico City, comprise the Political divisions of Mexico, Federal Entities of Mexico. It is divided in Municipalities of Nayarit, 20 municipalit ...

. It also lives in the

Gulf of California The Gulf of California (), also known as the Sea of Cortés (''Mar de Cortés'') or Sea of Cortez, or less commonly as the Vermilion Sea (''Mar Vermejo''), is a marginal sea of the Pacific Ocean that separates the Baja California peninsula from ...

. Other common names include Pacific rock shrimp and Japanese shrimp. In

Spanish Spanish might refer to: * Items from or related to Spain: **Spaniards are a nation and ethnic group indigenous to Spain **Spanish language, spoken in Spain and many countries in the Americas **Spanish cuisine **Spanish history **Spanish culture ...

it is called ' and '. This is a dominant

invertebrate Invertebrates are animals that neither develop nor retain a vertebral column (commonly known as a ''spine'' or ''backbone''), which evolved from the notochord. It is a paraphyletic grouping including all animals excluding the chordata, chordate s ...

in the ocean off

Southern California Southern California (commonly shortened to SoCal) is a geographic and Cultural area, cultural List of regions of California, region that generally comprises the southern portion of the U.S. state of California. Its densely populated coastal reg ...

, especially off

Los Angeles Los Angeles, often referred to by its initials L.A., is the List of municipalities in California, most populous city in the U.S. state of California, and the commercial, Financial District, Los Angeles, financial, and Culture of Los Angeles, ...

and

Orange Orange most often refers to: *Orange (fruit), the fruit of the tree species '' Citrus'' × ''sinensis'' ** Orange blossom, its fragrant flower ** Orange juice *Orange (colour), the color of an orange fruit, occurs between red and yellow in the vi ...

counties at depths of . There is a large population on the Palos Verdes Shelf.

Biology

Measured from the bases of the antennae to the

telson The telson () is the hindmost division of the body of an arthropod. Depending on the definition, the telson is either considered to be the final segment (biology), segment of the arthropod body, or an additional division that is not a true segm ...

, the male prawn reaches a maximum length around , and the female . It is the largest ''Sicyonia'' in the eastern Pacific. It is mostly reddish brown in color with more red on the underside. The legs are whitish with red patches. It often occurs with ''

Sicyonia disdorsalis ''Sicyonia'' is a genus of prawns, placed in its own family, Sicyoniidae. It differs from other prawns in that the last three pairs of its pleopods are uniramous, rather than biramous as seen in all other prawns. ''Sicyonia'' contains 52 extant ...

'', which it resembles, but it is larger and can be distinguished by the

seta In biology, setae (; seta ; ) are any of a number of different bristle- or hair-like structures on living organisms. Animal setae Protostomes Depending partly on their form and function, protostome setae may be called macrotrichia, chaetae, ...

e on its

carapace A carapace is a dorsal (upper) section of the exoskeleton or shell in a number of animal groups, including arthropods, such as crustaceans and arachnids, as well as vertebrates, such as turtles and tortoises. In turtles and tortoises, the unde ...

, the spines on its telson, the shape of the

genitalia A sex organ, also known as a reproductive organ, is a part of an organism that is involved in sexual reproduction. Sex organs constitute the primary sex characteristics of an organism. Sex organs are responsible for producing and transporting ...

, and other external characteristics. This prawn can be found on substrates of mud and shell debris, but it appears to prefer sand.

Spawning Spawn is the Egg cell, eggs and Spermatozoa, sperm released or deposited into water by aquatic animals. As a verb, ''to spawn'' refers to the process of freely releasing eggs and sperm into a body of water (fresh or marine); the physical act is ...

takes place in May through October, peaking in late summer. It occurs in water about deep. An

ovulating Ovulation is an important part of the menstrual cycle in female vertebrates where the egg cells are released from the ovaries as part of the ovarian cycle. In female humans ovulation typically occurs near the midpoint in the menstrual cycle and af ...

female begins to swim more than usual before releasing her eggs. One spawning yields an average of about 86,000 embryos. The prawn likely spawns multiple times during one season.

Molting In biology, moulting (British English), or molting (American English), also known as sloughing, shedding, or in many invertebrates, ecdysis, is a process by which an animal casts off parts of its body to serve some beneficial purpose, either at ...

occurs mostly in fall and winter, rarely during the summer breeding season.

Economics

There is a

commercial fishery Commercial fishing is the activity of catching fish and other seafood for commercial profit, mostly from wild fisheries. It provides a large quantity of food to many countries around the world, but those who practice it as an industry must often p ...

for this prawn in California, with most activity between Santa Barbara and Ventura, where it is abundant. It became a resource around 1966, when its economic potential was realized and

trawlers Trawler may refer to: Boats * Fishing trawler, used for commercial fishing * Naval trawler Naval trawlers are vessels built along the lines of a fishing trawler but fitted out for naval purposes; they were widely used during the World War I, Fir ...

began to target it. The industry grew slowly at first due to lack of demand for the animal. The fishery for this species and the California spot prawn (''Pandalus platyceros'') grew most during the 1970s. The spot prawn is larger and more valuable, but in 1982 the ridgeback prawn catch totalled 127,000,956 pounds, a haul worth $156,000,385.

References

{{Taxonbar, from=Q6493344 Dendrobranchiata Edible crustaceans Crustaceans of the eastern Pacific Ocean Crustaceans described in 1938