Potamon fluviatile crabs' unusual size, up to , and longevity (up to 15 years) are also interpreted as evidence of a long-established population, by analogy with island gigantism. On the island of Malta, "Potamon fluviatile" is rare and restricted to a few locations in the west of the island. On Gozo, there is a single population which inhabits a stretch of river only long. In the Balkan Peninsula, "Potamon fluviatile" is known to occur in Croatia, Montenegro, the Republic of Macedonia, Albania and Greece. There are four species of "Potamon" in the Balkans, and "P. fluviatile" is replaced by "Potamon ibericum" in
Blechnum fluviatile associates in the mixed broadleaf/podocarp forests of Rakiura include "Blechnum blechnoides" and "Blechnum durum". It was collected by William Colenso in December 1841, at the precise locality of woods near Poverty Bay in the North Island. Blechnum fluviatile Blechnum fluviatile is a fern known in the Māori language as kiwikiwi. A herbaceous plant, "B. fluviatile" is a "hard fern" of the genus "Blechnum" in the family Blechnaceae. It was identified by Patrick Brownsey in 1979. Other common names are star fern, creek fern, kawakawa and kiwakiwa. Ladderlike fronds of "B. fluviatile" measure up to long. Growing in a distinctive ground-hugging