Elegant Hermit Crab, Aniculus elegans

Elegant Hermit Crab, Aniculus elegans. Provided by the commercial fishermen of the greater Los Cabos area, Baja California Sur, April 2012. Length: 17 cm (6.7 inches). The crab had taken over a 6 inch Black Murex, Hexaplex nigritus, Shell.

Elegant Hermit Crab, Aniculus elegans. Underwater photographs taken in Zihuatanejo Bay, Guerrero, February 2020. Photographs courtesy of Ron Woheau, Zihuatanejo. The crab had taken over a 6 inch Prince Murex, Hexaplex princpes, Shell

General information: The Elegant Hermit Crab, Aniculus elegans, is a decapod and member of the Diogenidae or Hermit Crab Family, which are also known as “left handed hermit crabs” because in contrast to most other hermit crabs they have left claws that are bigger than the right claw. In Mexico this crab is known as ermitaño elegante or cangrejo erminaño. Hermit crabs date to at least the Cretaceous period of 100 million years ago. The Hermit Crabs reside in discarded snail shells and have a soft back end that needs to be protected and thus they keep their abdomen tucked inside the shell. Should they feel threatened they pull their heads and legs inside their underwater mobile homes. Through their use and recycling of these gastropods shells, hermit crabs are important allogenic ecosystem engineers in marine habitats and found from the intertidal to the deep sea.

Identification: The Elegant Hermit Crab has pink legs and claws and is irregularly banded with red; the tips of the claws are bright red and grooved. The hairs on the body and appendages are tan, tipped with white. The Elegant Hermit Crabs are very common and one of the largest species of hermit crabs reaching a maximum size of 7.5 cm (3.0 inches).

Habitat and Range: The Elegant Hermit Crab is found in sand rubble and among rocks within the low intertidal or subtidal zone at depths up to 46 m (150 feet). They range from the southern half of the Sea of Cortez and along the coast of the mainland south to Guatemala and are the only American hermit crab distributed in the Indo-Pacific. They are normally found in large gastropod shells including Hexaplex, Malea, Murex, Pleuroploca and Strombus.

Diet:  Elegant Hermit Crabs are omnivorous, grazing the reef scraping off any algae they can get their claws on and even eating small invertebrates.

Conservation Status:  From a conservation perspective the Elegant Hermit Crab has not been formally evaluated. However, they are common and of limited interest to most and should be considered to be of Least Concern.

Synonym:  Aniculus longitarsis