Northward spread of tropical affinity fishes: Caranx crysos (teleostea: Carangidae), a case study from the Mediterranean sea

Abstract

The blue runner Caranx crysos is a thermophilic species poorly investigated in the Mediterranean Sea. Although considered a typical inhabitant of the southern regions, it has recently established in northwest Sicily and, according to the data presented in this study, is now regularly caught in the central-southern Tyrrhenian Sea up to the Gulf of Naples. Some occurrences of the species were also documented in the Gulf of Taranto (Ionian Sea) and in more northerly localities of the Tyrrhenian Sea, such as Gaeta and Civitavecchia. These recent distributional records are in contrast with historical literature and museum collections which depict this species as very rare in the Italian seas and only sporadically occurring above the Strait of Sicily. In this paper, literature and museum collections were thoroughly investigated in order to obtain a satisfactory understanding of the species distribution in the Mediterranean. In addition, the hypothesis of a recent displacement of the northern limit of this species distributional range in the Mediterranean is discussed. © 2011 Unione Zoologica Italiana.