The European otter (Lutra lutra), also known as the Eurasian otter, Eurasian river otter, common otter and Old World otter, is a European and Asian member of the Lutrinae or otter subfamily, and is typical of freshwater otters. The European otter is a typical species of the otter subfamily. Brown above and cream below, these long, slender creatures are well-equipped for their aquatic habits. This otter differs from the North American river otter by its shorter neck, broader visage, the greater space between the ears and its longer tail. However, the European otter is the only otter in its range, so it cannot be confused for any other animal. Normally, this species is 57 to 95 cm (23-37 in) long, not counting a tail of 35-45 cm (14-18 in). The female is shorter than the male.  The otter's average body weight is 7 to 12 kg (15.4-26.4 lbs), although occasionally a large old male may reach up to 17 kg (37 lbs). The record-sized specimen, reported by a reliable source but not verified, weighed over 24 kg (53 lbs).
The European otter is the most widely distributed otter species, its range including parts of Asia and Africa, as well as being spread across Europe. Though currently believed to be extinct in Liechtenstein, and Switzerland, they are now very common in Latvia, along the coast of Norway and across Great Britain, especially Shetland, where 12% of the UK breeding population exist. Ireland has the highest density of Eurasian otters in Europe. In Italy, they can be found in the Calore River area. These creatures live in South Korea, and are endangered. In general, their varied and adaptable diets mean they may inhabit any unpolluted body of fresh water, including lakes, streams, rivers, and ponds, as long as the food supply is adequate. European otters may also live along the coast, in salt water, but require regular access to fresh water to clean their fur. When living in the sea, individuals of this species are sometimes referred to as "sea otters", but they should not be confused with the true sea otter, a North American species much more strongly adapted to a marine existence.
spotted in the Vila Nova de Gaia Biological Park,very well cared and the place is beautiful