Next up are the most common and the rarest: Eurasian & Hairy-nosed Otters

Developing from the same lineage as the Sea Otter and Spotted-necked Otter are the Lutra-type otters of the Lutra and Aonyx sub-branches. The oldest sub-branching and the 2 oldest extant (extant= currently living) otters in this group are the Eurasian Otter (Lutra lutra) and the Hairy-nosed Otter (Lutra sumatrana).

 The Eurasian Otter (Lutra lutra) is found throughout Europe, Asia, and in parts of northern Africa. It is the only otter living through much of its range, so it is rarely confused for any other animal. Despite being, for otters, habitat generalists (meaning that they live in a very wide variety of habitats)  and inhabiting a large geographical range, their populations continue to decline and are listed as "Near Threatened" by IUCN RedList

They are a very adaptable otter in habit and diet; they use both fresh and salt water areas but require access to fresh water so they can clean their fur.

Eurasian otters get up to ~56" (1.4 meters) long and ~26 lbs (12kg). They tend to live alone, except when mating or raising pups.

Hairy-nosed ottera (Lutra sumatrana) are found in southeastern Asia: Cambodia, Vietnam, Thailand, Indonesia, Malaysia, and possibly Burma. The populations are isolated and very vulnerable, and considered to be in rapid decline so they are listed as "Endangered" by IUCN RedList.

 The Hairy-nosed otter is believed to be rarest of all of the otters. The photo above was taken in captivity, of one of only 2 hairy-nosed otters held in *zoo* captivity.
Hunting and habitat degradation are it's biggest threats.

Hairy-nosed otters are smaller than Eurasian otters, generally to ~52" (1.3 m) long and 17 lbs (8kg).
Very little is known about their social activities, but it is believed that they are more social than Lutra lutra (Eurasian otter).