CONTRIBUTION TO THE KNOWLEDGE OF PERCNON GIBBESI (DECAPODA, GRAPSIDAE), AN EXOTIC SPECIES SPREADING RAPIDLY IN SICILIAN WATERS

Abstract

[Percnon gibbesi, a subtropical crab recently recorded for the first time in the Mediterranean, has now been found at Pantelleria (Strait of Sicily) and on the coast of mainland Sicily. The main morphological traits of the collected specimens are presented. It seems that P. gibbesi is forming stable populations in Sicilian waters, where juveniles as well as ovigerous females have been found. A few hypotheses are suggested to explain the spread of this species into the western Mediterranean: (i) wide capability of adaptation, (ii) larval strategy, (iii) favourable environmental conditions, probably linked to recent climate change, and (iv) absence of competitors. Percnon gibbesi, un crabe subtropical, recemment observe pour la premiere fois en Mediterranee vient d'etre trouve a Pantelleria (detroit de Sicile) et sur la cote de Sicile meme. Les principaux caracteres morphologiques des echantillons recoltes sont presentes. Il semble que P. gibbesi de Sicile constitue des populations stables dans les eaux siciliennes ou ont ete trouves aussi bien des juveniles que des femelles ovigeres. Quelques hypotheses sont avancees afin de comprendre la distribution de l'espece en Mediterranee occidentale: (i) large capacite d'adaptation, (ii) strategie larvaire, (iii) conditions environnementales favorables, probablement liees au recent changement climatique et (iv) absence de competiteurs., Percnon gibbesi, a subtropical crab recently recorded for the first time in the Mediterranean, has now been found at Pantelleria (Strait of Sicily) and on the coast of mainland Sicily. The main morphological traits of the collected specimens are presented. It seems that P. gibbesi is forming stable populations in Sicilian waters, where juveniles as well as ovigerous females have been found. A few hypotheses are suggested to explain the spread of this species into the western Mediterranean: (i) wide capability of adaptation, (ii) larval strategy, (iii) favourable environmental conditions, probably linked to recent climate change, and (iv) absence of competitors. Percnon gibbesi, un crabe subtropical, recemment observe pour la premiere fois en Mediterranee vient d'etre trouve a Pantelleria (detroit de Sicile) et sur la cote de Sicile meme. Les principaux caracteres morphologiques des echantillons recoltes sont presentes. Il semble que P. gibbesi de Sicile constitue des populations stables dans les eaux siciliennes ou ont ete trouves aussi bien des juveniles que des femelles ovigeres. Quelques hypotheses sont avancees afin de comprendre la distribution de l'espece en Mediterranee occidentale: (i) large capacite d'adaptation, (ii) strategie larvaire, (iii) conditions environnementales favorables, probablement liees au recent changement climatique et (iv) absence de competiteurs.]