S. Florida to S. Brasil, Caribbean; arrived by rafting on floating algae or debris in British Isles, Ireland, Netherlands, Mediterranean; Singapore… The species seems to be able to survive in relatively cold waters (western Ireland, southern North Sea), as well as in hypersaline environments (Rio Grande do Norte, among osyter bead for example).
 
Filter feeder in the infralittoral, attached on and under rocks, or in crevices, on piers, in sessile bivalve colonies… Original taxon: Perna bicolor. A synonym is semiaurita (Linnaeus, 1764) sensu Dall & Simpson, 1901 (“The Mollusca of Porto Rico”, Bulletin of the United States Fish Commission vol. 20(1), Washington 1900, p.463).

The shell can be contorted to subquadrate; the outside, yellowish near the core and becoming darker towards the ventral margin, bears irregular scales arranged more or less concentrically in the first stages of growth; on the dark ventral extensions, these scales can bear a kind of radiating pattern, especially on old specimens; the inside has a nacreous core, markedly recessed, white to yellow, or with some blue hue; the ventral extensions are of the same colour than the external surface; each valve bears a more or less pronounced abductor muscle scar. Above: a specimen from E. Panama. 55mm.

The dispersion of bicolor throughout the Atlantic Ocean includes many different kinds of vectors, such as relocation of oil or gas platforms, Sargassaceae or plastic boxes travelling on the Gulf Stream, etc. Regarding the Mediterranean, « the northward shift of the 15°C February isotherm divide, providing a warmer corridor which directly connects the Strait of Gibraltar with the eastern Mediterranean (Bianchi et al., 2012), allows tropical taxa to bypass most of the western Mediterranean Sea (Di Silvestro et al., 2010), rapidly reaching the most favourable Levantine Basin throughout the Mid-Mediterranean Jet Current. » Hence the presence of well established communities in the eastern part of the Mediterranean, while the colder western basin is, for the moment (2010-2030), free of bicolor. – Stená Cove, Kaloí Liménes, Phaistós dímos, S. Crete. 31mm.