Cryptic diversity of the widespread scorched mussel Brachidontes pharaonis-variabilis species complex

Abstract

The phenomenon of bioinvasions, when species spread beyond their native ranges, is widely studied in terms of biological and ecological characteristics of the species involved. However, some cases need taxonomic deepening due to misidentifications which often occur. The Brachidontes pharaonis-variabilis species complex, a mussel group, exemplifies these challenges. Originally from the Indo-Pacific region, the species Brachidontes pharaonis has successfully invaded the Mediterranean Sea. The true boundaries of its Indo-Pacific range are poorly understood, partly due to confusion with a similar species, B. variabilis. This morphological overlap complicates accurate distribution mapping. This paper emphasizes the need for integrative analyses and reports morphometric and genetic variability within the complex.