top of page

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)

-True Crabs (Infraorder Brachyura)​​

-Eubrachyuran Crabs (Zoosection Eubrachyura)

-Thoracotrematan Crabs (Zoosubsection Thoracotremata)

-Land, Shore, and Marsh Crabs (Superfamily Grapsoidea)

-Shore Crabs (Family Grapsidae)

-Genus Grapsus

-Sally Lightfoot Crab (Grapsus grapsus)


The Sally Lightfoot Crab, Grapsus grapsus, is one of several crabs that are commonly referred to as “Sally Lightfoots.” They are members of the Grapsidae Family and known in Mexico as abuente negro. They inhabit all coastal rock formations and have a unique ability to hang on the rocks when bombarded by large crashing waves. Sally Lightfoots feed on algae, dead fish, dead birds, and dead seals, and they have limited value other than they are a premiere fresh cut bait for which they are highly esteemed by local surf fishermen.

Sally Lightfoot Crab

Grapsus grapsus

Diet

  • Primarily algae, including green and red algae growing on intertidal rocks.

  • Also feeds on seaweed, detritus, dead fish, barnacles, molluscs, small crustaceans, and other marine invertebrates.

  • An opportunistic scavenger that helps keep rocky shorelines clean by consuming decaying organic matter.

Range

  • Found along the tropical eastern Pacific, from the Gulf of California and the Pacific coast of Mexico south through Central America, Colombia, Ecuador, and Peru.

  • Occurs along the Pacific coast of Mexico, including the Zihuatanejo region.

Habitat

  • Inhabits wave-swept rocky shores, tide pools, lava rocks, cliffs, and jetties in the intertidal zone.

  • Usually found on exposed rocks just above or within the splash zone, where it can move rapidly over wet, slippery surfaces.

  • Shelters in rock crevices and beneath boulders during high tide or when threatened.

Size

  • Carapace width: 5–8 cm (2.0–3.1 in)

  • Leg span: Up to 20 cm (8 in)

  • Weight: Typically 100–250 g

bottom of page