Potamon fluviatile icon in Malta following its legal protection in 1993, although not all scientists recognise the taxon. Potamon fluviatile Potamon fluviatile is a freshwater crab found in or near wooded streams, rivers and lakes in Southern Europe. It is an omnivore with broad ecological tolerances, and adults typically reach in size during their 10–12 year lifespan. They inhabit burrows and are aggressive, apparently outcompeting native crayfish. "P. fluviatile" has been harvested for food since classical antiquity, and is now threatened by overexploitation. Many of the island populations are particularly vulnerable, and the Maltese subspecies has become a conservation icon. A population
Potamon fluviatile six "nationes", or "tribes". Natio "fluviatilis" was found in northern Italy, natio "tarantium" in southern Italy, and nationes "thessalonis", "kühnelti" and "laconis" were found in parts of Greece. The geographical distribution of natio "leucosis" was not reported, and it was suggested that a further (undescribed) tribe inhabited the Greek island of Andros. Despite this wealth of infraspecific taxa, they are rarely used by scientists, and some have questioned directly the value of defining infraspecific taxa within "P. fluviatile". In 1990, the population on Malta was described as a separate subspecies, "Potamon fluviatile lanfrancoi", and that taxon has become a conservation