Percnon gibbesi explained

Percnon gibbesi is a species of crab.^[1] It is one of at least two species commonly called Sally Lightfoot (the other being the semi-terrestrial Grapsus grapsus from the Pacific coast of the Americas), and is also referred to as the nimble spray crab or urchin crab.^[2] It has been described as "the most invasive decapod species to enter the Mediterranean".^[1]

Description

Adults have a carapace wide, and legs with yellow rings at the joints.^[3] Each of the five pairs of walking legs has a row of spines along the leading edge.^[3] Females carrying eggs have been caught off West Africa between February and April and August; the larvae which hatch from them are planktonic and long-lived, which may contribute to the species' invasiveness.^[3]

Taxonomy

The genus Percnon is currently placed in the family Percnidae, although it has also been placed in Plagusiidae.^[4]

Distribution

P. gibbesi is one of the most widespread grapsid crabs, being found on both sides of the Atlantic Ocean and on the Pacific coast of North America. There, its range extends from California to Chile, while in the Atlantic, it occurs natively from Florida to Brazil and from Madeira to the Gulf of Guinea.^[3] It has recently invaded the Mediterranean Sea, having first been discovered at Linosa, Sicily in 1999.^[5] It has subsequently been found on the Balearic Islands, in Greece, in Libya in Malta and in Israel.^[6]

Ecology

Unusually among temperate crabs, P. gibbesi is strictly herbivorous.^[7] In the Caribbean Sea, P. gibbesi is associated with the sea urchin Diadema antillarum.^[8] In the Mediterranean Sea, P. gibbesi lives almost exclusively among boulders, and is out-competed by the native species Pachygrapsus marmoratus.^[9] P. gibbesi is preyed upon by fish and invertebrates.^[3]

Notes and References

1. JMBA2 Biodiversity Records . Racing across the Mediterranean — first record of Percnon gibbesi (Crustacea: Decapoda: Grapsidae) in Greece . S. Cannicci . L. Garcia . B. S. Galil . amp . 2006 . dead . https://web.archive.org/web/20110721043706/http://www.mba.ac.uk/jmba/pdf/5300.pdf . 2011-07-21 .
2. Web site: Percnon gibbesi . Florent's Guide To The Tropical Reefs . Florent Charpin . January 9, 2010.
3. Web site: Percnon gibbesi . Delivering Alien Invasive Species Inventories for Europe . January 9, 2010 . B. S. Galil . November 6, 2006 . https://web.archive.org/web/20121017151844/http://www.europe-aliens.org/speciesFactsheet.do?speciesId=100708 . October 17, 2012 . dead .
4. . 2008 . 17 . 1–286 . Systema Brachyurorum: Part I. An annotated checklist of extant Brachyuran crabs of the world . Peter K. L. . Ng . Danièle Guinot . Peter J. F. Davie . amp .
5. The exotic crab Percnon gibbesi (H. Milne Edwards, 1853) (Decapoda, Grapsidae) in the Central Mediterranean . . 64 . 3 . 337–340 . Marco Relini . Lidia Orsi . Valentina Puccio . Ernesto Azzurro . 2000 . 10.3989/scimar.2000.64n3337. free .
6. . 2008 . 3 . 2 . 243–245 . 10.3391/ai.2008.3.2.16 . The first record of Percnon gibbesi (H. Milne Edwards, 1853) (Crustacea: Decapoda: Plagusiidae) from the southern rim of the Mediterranean . Housameddin M. Elkrwe . Hasan M. Elhawaj . Bella S. Galil . Abdallah ben Abdallah . dead . https://web.archive.org/web/20110721010808/http://www.aquaticinvasions.ru/2008/AI_2008_3_2_Elkrwe_etal.pdf . 2011-07-21 . free .
7. Feeding habits of Percnon gibbesi (H. Milne Edwards, 1853) in the Sicily Strait . . 557 . 1 . 2006 . 10.1007/s10750-005-1310-2 . 79–84 . V. Puccio . M. Relini . E. Azzurro . L. Orsi Relini . 5970848 .
8. Web site: Frequency of Percnon gibbesi in relation to Diadema antillarum at Rodney's Rock . Rickey Wallace . 2007 . .
9. Biology and interspecific interactions of the alien crab Percnon gibbesi in the Maltese Islands . Marija Sciberras . Patrick J. Schembri . amp . 10.1080/17451000801964923 . . 4 . 5 . 2008 . 321–332. free .