Peanut Rock Shrimp

Sicyonia penicillata

The peanut rock shrimp, a member of the family Sicyoniidae, is a benthic crustacean found primarily in the Eastern Central Pacific, specifically off the coasts of Mexico and Costa Rica. Divers may encounter this species on sandy and muddy bottoms, typically at depths ranging from 26 to 139 meters. However, most recorded sightings occur at shallower depths, with 73% of observations at less than 40 meters and 90% at less than 70 meters. The peanut rock shrimp is part of the order Decapoda, which is primarily composed of gonochoric species, meaning individuals are distinctly male or female. Their mating behavior often involves a precopulatory courtship ritual, utilizing olfactory and tactile cues, with sperm transfer generally being indirect. Divers can expect to find this species in tropical waters, where it contributes to the benthic ecosystem.