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
IS-IS of a single area. IS-IS also does not require Area 0 (Area Zero) to be the backbone area through which all inter-area traffic must pass. The logical view is that OSPF creates something of a spider web or star topology of many areas all attached directly to Area Zero and IS-IS by contrast creates a logical topology of a backbone of Level 2 routers with branches of Level 1–2 and Level 1 routers forming the individual areas. IS-IS also differs from OSPF in the methods by which it reliably floods topology and topology change information through the network. However, the