Species of the Month

Halloween is just around the corner. Traditionally, we examine a spooky critter with a connection to Halloween for the Species of the Month. This year let’s try something different. There’s nothing scary about a ghost crab, but its name fits the season. 

Ghost crab (Science Magazine)

Scientific name: Ocypode quadrata 

Kingdom: Animalia (animals)

Class: Malacostraca (soft-shelled crustaceans)

Order: Decapoda (ten-footed crustaceans)

Range: Rhode Island to Brazil 

Habitat: Ocean or estuary beaches, from the tide line to the dunes 

Lifespan: 3 years 

Diet: Bean clams, mole crabs, sea turtle eggs and hatchlings, organic detritus 

Predators: Shore birds, gulls, raccoons 

Conservation status: No special protection

Other info: Ghost crabs are small, nocturnal crustaceans. They grow to about a two inch carapace (back shell) with long legs and eye stalks, and their claws are uneven sizes. Ghost crabs hatch from an egg in the ocean and go through six larval stages before developing into adult crabs. Unlike other crabs that can only mate when the female is molting, ghost crabs can and do mate at anytime after reaching maturity which is usually after a year old.  

Juvenile ghost crab (NPS)

Ghost crabs live in burrows in the sand. They plug the holes during the day and emerge at night for feeding and mating. Mating occurs near the male’s burrow. They travel several feet per night and may not return to the same burrow. Occasionally they will go into the water to wet their gills; they are also capable of absorbing water from the sand into their gills. 

Ghost crabs can be used as an indicator species to monitor the health of their habitat. Populations can be easily estimated by counting burrows. Knowing the status of the crab population can tell what kind of impact human activities are having on the ecosystem overall. Off road vehicles and coastal development are the biggest challenges we give them. 

A pair of ghost crabs (NPS)

Once again this week's information comes from the Animal Diversity Web at University of Michigan. Next week is a rerun. We'll have fresh content after Halloween. Stay tuned!