Presence of the invasive species Indo-Pacific Swimming Crab Charybdis hellerii A. Milne-Edwards, 1867 on the Mexican Pacific coast detected by molecular identification

Abstract

Crabs of the species Callinectes arcuatus Ordway, 1863 were caught in Cuyutlán Lagoon, Colima, Mexico (19°0′38.48″N, 104°14′50.65″W). Among them, 1 specimen of Charybdis hellerii A. Milne-Edwards, 1867 was caught. This specimen was molecularly identified by the forensic information nucleotide sequencing (FINS) procedure using a fragment of the 16S rRNA gene (518 bp). The 16S rRNA sequence of C. hellerii (GenBank accession number PQ800082) showed 83% identity with the C. arcuatus sequences in the GenBank database and those obtained here (GenBank accession numbers PQ800080 and PQ800081). Reports by citizen scientists on iNaturalist have indicated the presence of C. hellerii in the waters of Colima since 2019. However, this is the first time that molecular markers confirm its presence on the Mexican Pacific coast. Further research is needed to understand the extent of C. hellerii propagation along the Mexican Pacific coast, as its presence since 2019 could indicate an established population in this area. The presence of this species is concerning, as it could affect the populations of other commercially important native crab species.