A rare sighting of a stomatopod (aka mantis shrimp) occurred in Elkhorn Slough. Dr. Rikke Jeppesen, an estuarine ecologist for the Elkhorn Slough National Estuarine Research Reserve (ESNERR), found this rare animal while inspecting crab traps on February 10, 2016.
This species occurs south of Point Conception near Santa Barbara and extends down to Mexico and as far south as the Galapagos Islands. It is rarely seen in southern California, so it might be yet another example of a species that headed north during the years dominated by the “Blob” in 2014-15.
The species is Pseudosquillopsis marmorata, and according to Light’s Manual (4th Edition), its dactylus is designed for “spearing” rather than a “smashing” prey. Stomatopods have appendages (dactyls) that are modified in one of two forms: a thin spear that is used to stab prey versus a thick, heavily armored dactyl that is used to smash prey (like clams, snails, crabs). This specimen was about 150 mm in total length, which is an adult and therefore arrived prior to 2016. Larvae of several species from Mexico and further south have been recruiting to central California in the last couple of years.
Light’s Manual reports a juvenile being collected off Monastery Beach and a 124 mm adult female collected in Tomales Bay (both prior to 2007). Elkhorn Slough Education Coordinator Kenton Parker had earlier collected this species at a nearby site (Whistlestop Lagoon, also in Elkhorn Slough) in February 2011.