Potamon fluviatile 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 in Rome may have been brought there before the founding of the Roman Empire. Adult "Potamon
Blechnum fluviatile a short trunk central to a surrounding colony. The hardy "B. fluviatile" requires moist, shaded conditions for optimal growth. A small ground fern, the "B. fluviatile" is native to New Zealand and southeast Australia, a syntype common throughout the country in damp, shady areas in acidic, moist and boggy soil, beside streams in forest areas. This fern species occurs throughout much of New Zealand's forests, including much of the forested area of North Island; west, north and south coasts of South Island; and Stewart Island/Rakiura; moreover, it occurs in parts of the coastal forests of southeast Australia. Example understory flora