Sally Lightfoot Crab or Rock CrabGrapsus albolineatus

Category
  • Rocky Shores
Tags
  • Crustaceans
  • Crab

Description

G. albolineatus is similar to its cousin Grapsus tenuicrustatus. Both are members of the Grapsidae family, which are crabs marked with a steep wide front and males having an abdomen occupying the full length of their underside. The front of G. albolineatus is not as noticeably wide. The crab has a depressed carapace and an indistinct and rough brancho-cardiac groove. [1] G. albolineatus has a carapace width of 40 millimeters and 35 millimeters in length. It is differentiated from Grapsus tenuicrustatus by its fingers of chelae which are dark red or brown.

 

[1] ETI BioInformatics. n.d. "Marine Species Identification Portal." Crabs of Japan Grapsus albolineatus. Accessed July 2018. http://species-identification.org/species.php?species_group=crabs_of_japan&id=1653.

Habitat and ecology

G. albolineatus is present throughout the Indo-Pacific region. It can be observed on the rocky shores throughout Mauritius, or occasionally on reef flats near rocky shores. It is active at night and rarely seen during daytime. It is a very shy and fearful crab which will disappear in crevices and will blend in with its surroundings at the sight of potential danger. [1] Like others in the Grapsidae family, it is a grazer and feeds on microscopic algae found on the rocks[2].

 

Conservation and management

The species is not currently listed in the IUCN Red List of Threatened Species. It is common throughout its range. Habitat modification by humans may affect local populations and this invertebrate may be affected by ocean acidification as the effects of climate change become increasingly felt.

 

[1] Wild Singapore Fact Sheets. 2016. Sally-light-foot crab Grapsus albolineatus. Accessed April 2018. http://www.wildsingapore.com/wildfacts/crustacea/crab/grapsidae/albolineatus.htm

[2] Richmond, Matthew (ed.). 2011. A fieldguide to the seashores of Eastern Africa and the Western Indian Ocean islands. Sida/WIOMSA.

 

Did you know?

The type locality of G. albolineatus – the geographic location where the species was originally found – is Mauritius.

References:

ETI BioInformatics. n.d. "Marine Species Identification Portal." Crabs of Japan Grapsus albolineatus. http://species-identification.org/species.php?species_group=crabs_of_japan&id=1653.

 

Wild Singapore Fact Sheets. 2016. Sally-light-foot crab Grapsus albolineatus. http://www.wildsingapore.com/wildfacts/crustacea/crab/grapsidae/albolineatus.htm

 

Richmond, Matthew (ed.). 2011. A fieldguide to the seashores of Eastern Africa and the Western Indian Ocean islands. Sida/WIOMSA.

Other Ecosystems