Target Rock Shrimp, Sicyonia penicillata

Target Rock Shrimp, Sicyonia penicillata. Shrimp provided by the commercial fishermen of the greater Los Cabos area, Baja California Sur, October 2009. Size: 8.0 cm (3.1 inches).

Phylogeny:  The Target Rock Shrimp, Sicyonia penicillata (Lockington, 1879), is a member of  the  Sicyoniidae Family of Rock Shrimp. The genus Sicyonia is the only genus in this family, and the are fifty-one species in this genus. Target Rock Shrimp are also known as Japanese Shrimp and Peanut Rock Shrimp and in Mexico  as camarón rojo sin manchas and camarón cacahuate. Rock Shrimp derive their name from their very hard exoskeletons.

Morphology:  Target Rock Shrimp are tan to light gray in color with gray, brown, or black mottling. They have a robust carapace with a well developed rostrum that has one tooth with a pronounced raised carina and biramous antennules. Both sides of the carapace are marked with an eye-spot that appears like a target, giving them their common name. The spot may be reddish-brown or purplish brown, and sometimes has a yellow center. They have a maximum body length of 8.0 cm (3.1 inches), though some sources extend that to 10.4 cm (4.2 inches).

Habitat and Distribution:  Target Rock Shrimp reside over sand and mud in the intertidal zone to depths up to 103 m (338 feet).  In Mexican waters  Target Rock Shrimp are found in all waters of the Pacific Ocean, including the entire Gulf of California. They are the commonest member of the Sicyonia Genus.

Diet:  The diet of Target Rock Shrimp has not been formally documented. Other members of this genus eat bivalves and crustaceans.

Predators:  Target Rock Shrimp are preyed upon by fish, fur seals, and sharks, such as the Pacific Angel Shark, Squatina californica.

Reproduction: Target Rock Shrimp are gonochoric (male or female for life). Reproduction is sexual with fertilization occurring externally. The eggs hatch into planktonic larva.

Ecosystem Interactions:  Ecosystem interactions specific to Target Rock Shrimp has not been formally documented.

Human Interactions:  In the 1930’s and 1940’s Target Rock Shrimp were targeted by Japanese commercial fishermen. Because of the hard shells, this species was slow to catch on with other consumers and they were generally considered bycatch. In recent years they have become an increasingly important commercial fishery in Mexico. From a conservation perspective they have not been formally evaluated however they are  common, with a relatively wide distribution, and should be consider to be of Least Concern.

Synonym:   Eusicyonia penicillata.