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Crustaceans of Zihuatanejo

SUBPHYLUM CRUSTACEA

-Animals (Kingdom Animalia)

-Arthropods (Phylum Arthropoda)

-Crustaceans (Subphylum Crustacea)

-Typical Crustaceans (Superclass Multicrustacea)

-Malacostracans (Class Malacostraca)

-Decapods, Isopods, and Allies (Subclass Eumalacostraca)

-Decapods and Krill (Superorder Eucarida)

-Decapods (Order Decapoda)

-Crabs, Lobsters, Shrimps, and Allies (Suborder Pleocyemata)

-Anomurans (Infraorder Anomura)

-Hermit Crabs (Superfamily Paguroidea)

-Left-handed Hermit Crabs (Family Diogenidae)

-Genus Calcinus

-Red-leg Hermit Crab (Calcinus californiensis)


The Red-leg Hermit Crab (Calcinus californiensis) has bright scarlet red legs. The two claws are dark greenish-grey with red seams along each joint and around the claws. The eye stalks are also dark greenish-grey with white rims around the edge if its black eyes. The Red-leg Hermit Crabs are found in groups in the low intertidal and shallow sub-tidal zones over rock and coral structures at depths up to 20 feet from the central Sea of Cortez south to Acapulco along the coast of the Mexican mainland.

Red-leg Hermit Crab

Calcinus californiensis

Diet

  • Omnivorous scavenger that feeds on filamentous algae, detritus, decaying plant and animal matter, carrion, and small invertebrates.

  • Also grazes on biofilms and microorganisms growing on rocks and coral.

  • Plays an important role in keeping reef and rocky-bottom habitats clean by recycling organic material.

Range

  • Found in the eastern Pacific Ocean, from the Gulf of California south along the Pacific coast of Mexico to El Salvador.

  • In Mexico, it occurs from Puerto Peñasco, Sonora, south through the Pacific states, including Guerrero and the Zihuatanejo region, to Huatulco, Oaxaca.

Habitat

  • Inhabits the lower intertidal zone and shallow subtidal waters to depths of approximately 15–25 m (50–82 ft).

  • Common on rocky reefs, coral communities (especially Pocillopora coral), tide pools, and rocky substrates where empty gastropod shells are abundant.

  • May occur in large aggregations on suitable reefs and rocky shorelines.

Size

  • Shield length: 4–10 mm (0.16–0.39 in)

  • Overall body length: Approximately 2–4 cm (0.8–1.6 in), depending on the shell occupied.

  • Weight: Typically 2–10 g, depending on shell size.


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