Classification of the Neotropical Otter

When men of science first started naming the animals of central and south America, they found a lot of similar otters differing in rhinarium form, and rather less in size, colouring and claw development.

These excellent drawings by J.A. Davies (in Proceedings of the First Working Meeting of the Otter Specialist Group, 1977) show the range of variation in the otters that would eventually all become Lontra longicaudis.
1818	Olfers named a medium sized river otter from southern Brazil Lutra longicaudis
1823	Cuvier identified a species of river otter from the coasts of eastern Venezuela through Trinidad down the east coast of Brazil as Lutra enudris, splitting it into three subspecies: L. e. enudris, L. e. insularis, and Thomas added L. e. mitis.
1838	Lutra longicaudis renamed (or re-discovered) Lutra platensis by Waterhouse.
1897	Major identified a species ranging from Mexico to northern Ecuador and called it Lutra annectans.  This was subsequently split into five subspecies: L. a. annectens, L. a. colombiana, L. a. latidens, L. a. paralina, L. a. repanda.
1908	Thomas named the otter of the Peruvian coast Lutra incarum.
1924	Cabrera identified the otter of Costa Rica as Lutra mesopetes.

By the 1930s, there were six species of Central and South American medium-sized river otters, with eight further subspecies divisions.  People began to suspect that there was something wrong with this scenario.  Some people, such as J.A. Davies, who had immense experience in working with the American river otters, felt that L. canadensis, longicaudis, provocax and felina were subspecies of a single species.

Van Zyll de Jong did much work reviewing the classification of the New World Otters based on morphology and anatomy, and came to the conclusion that the River Otters of the New World were not so closely related to the Old World ones, and proposed the generic name Lontra for them. He further suggested that all apart from L. canadensis (the North American River Otter) and L. felina (the Marine Otter or Sea Cat) were all one species, with a variable rhinarium shape (Van Zyll de Jong 1972, 1987, 1991); he gave it the oldest valid name for the whole lot, Lontra longicaudis. Koepfli & Wayne's 1998 work on cytochrome b variations between different species of otters supported this, and in their 2003 paper, five other genetic markers agreed that the three similar Lontra species, L. canadensis, L. longicaudis and L. felina form a fairly tight monophyletic group. They suggest that the Neotropical and Marine Otters are the least different from each other of any otter species, and diverged about 1.7 mya, possibly as L. canadensis radiated through Central and South America after the formation of the Panamanian landbridge 203 mya.

So now we have one, highly variable species, the Neotropical Otter, Lontra longicaudis (the Long-Tailed Otter).  Of course, the Neotropical Otter is currently split into three subspecies . . .

Other Names for the Neotropical Otter