DISCOVERIES OF NEW SPECIES

by Whit Gibbons

October 23, 2005

Of the scientific advancements in zoology that have occurred in the past year, two are particularly intriguing: identification of a salamander and a rodent hitherto unknown to scientists. The discovery of the salamander extends the geographic range of the group to another continent and provides a fresh perspective on the historical patterns of geographic distribution. The rodent is so distinctive from those found anywhere else in the world that it has been placed in a family of its own.

The salamander discovery was reported in the scientific journal “Nature” by M. S. Min of Seoul National University and several colleagues, including Ron Brandon of Southern Illinois University from whom I took herpetology at the University of Alabama several decades ago. Another participant in the identification of the new salamander was David Wake of the University of California, Berkeley. Dave is internationally known for his research on the evolution and ecology of salamanders.

These scientists and others were involved in the report because identifying it was a challenge. It was the first salamander in that particular family (Plethodontidae) ever reported from Asia. The Plethodontidae has more species than all the other families of salamanders combined, 377 of the 550 species of the world's salamander species. But with the exception of a half dozen species from the Mediterranean region, all species in the family were formerly known only from the Western Hemisphere. Most are in Central and South America. The southeastern states have more than 70 species in the family.

The new Asian salamander differs from others in the family genetically, and the bone structures of the feet and skull are different, something only experts could determine. But it is similar to the American forms in having no lungs. The species has presumably been separated from the North American members of the family for more than 65 million years, which gives insight into the ancient evolution and global distribution patterns of salamanders.

Experts were also needed to assess the proper taxonomic placement of a newly identified species of mammal from Southeast Asia. Paulina D. Jenkins of the British Museum of Natural History, London, and colleagues conducted DNA analyses to confirm the genetic individuality of the species, now called the Laotian rock rat. In the Khammouan Province of Lao Peoples Democratic Republic (Laos), where the first specimen known to science was found, the creature is called kha-nyou (my bet is that this means rock rat in Laotian). Interestingly, the specimen was found in an outdoor market; apparently the species is well-known to natives of the region who consider kha-nyou a food item.

The rodent is not simply a new species; it represents a new genus and new family of mammals, the first to be described in more than 30 years. The closest relatives of the new species are rodents from Africa and South America, not Asia. As with the Asian salamander, scientists are intrigued by how it got where it is when similar species did not. The Laotian rock rat, which reaches about a foot in length, has been described as looking like a cross between a rat and a squirrel or like a guinea pig with a long tail.

Although not new, an extraordinarily large specimen of a species was washed ashore in Tasmania in July. Most scientists agree that the giant squid is the largest invertebrate in the world, reaching enormous weights and lengths. But because they live deep in the ocean little is known of their habits. Even sightings of live specimens in their native habitat are rare, thus giant squid that are washed ashore dead or captured incidentally by fishermen are considered valuable for scientific observations. The Tasmanian specimen weighed more than 500 pounds and was estimated to be about 50 feet long. The largest squid ever found weighed nearly a ton.

The importance of studying a giant squid in Tasmania or identifying species in Asia previously unknown to scientists transcends the individual achievements. Such scientific accomplishments underscore the importance of scientists who can recognize new life forms when they find them, the value of experts who can properly classify such animals, and the marvel of life’s many mysteries that still await our full understanding.



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