Brown Mantis Shrimp, Parasquilla similis

Brown Mantis Shrimp, Parasquilla similis. Shrimp regurgitated by a 30 cm Goldspotted Sand Bass, Paralabrax auroguttatus, caught from coastal waters off Loreto, Baja California Sur, May 2024. Length: 10.4 cm (4.0 inches).

Phylogeny: The Brown Mantis Shrimp, Parasquilla similis (Manning, 1970), is a stomatopod  that is a member of the Parasquillidae Family of spearing mantis shrimps. The Genus Parasquilla is one of three Genera in this family, and consists of five species. They are a spearing mantis shrimps that are also known as “thumb splitters” because of their ability to cause injury if handled improperly. In Mexico, this species is known as estamatópodo café.

Morphology: The carapace of the Brown Mantis Shrimp covers the rear of the head, and the first four thoracic segments. Each thoracic and abdominal segment has small, regularly spaced, whitish blotches. The claws, including the spearing claw, bear teeth. Their compound eyes are located on stalks, with each eye capable of independent movement. Adult Brown Mantis Shrimps range in length from 10.4 cm (4.0 inches) to 21 cm (8.0 inches).

Habitat and Distribution:  Brown Mantis Shrimp reside in burrows in the sand. Because they spend almost all their time in burrows, they are seldom seen. Most observations of this species occur when individuals are brought up in deep water shrimp trawls, or when they are found in the stomachs of fish. Brown Mantis Shrimps are found at depths between 30 m (100 feet) and 125 m (410 feet).  In Mexican waters they are found from the central Sea of Cortez south and along the entire Pacific coast of the mainland. They are absent from the west coast of the Baja Peninsula.

Diet:  Brown Mantis Shrimp are ambush predators, feeding on small fish and other small soft-bodied invertebrates.

Predators:  Brown Mantis Shrimp are prey for larger, bottom-feeding fish.

Reproduction: Brown Mantis Shrimp reproduce sexually, with males assisting gravid females in co-parenting the eggs. Once the eggs hatch the hatchlings drift around as plankton before settling to begin their benthic life.

Ecosystems Interactions:  Reports of Brown Mantis Shrimps sharing their burrow with other species, or of other forms of commensalism have not been documented.

Human Interaction:  While many species of mantis shrimps are consumed as a human food substance, the Brown Mantis Shrimp is too rare and too difficult to catch to be targeted as a food species. They are caught as a bycatch by shrimp trawlers which may have some impact on local populations. From a conservation perspective they are currently considered to be of Least Concern with stable, widely distributed populations.