A new study by researchers at the University of Missouri shows that salamanders use migration as a response to environmental changes that occur when forests are clearcut. Not surprisingly, during the two year period of study, few salamanders migrated into the clearcut forest. The study does show that there is potential that salamanders that leave clearcut forests could return to repopulate the evacuated areas.

Image courtesy of Animal Tracks of Minnesota & Wisconsin

While at a cabin in Ladysmith, WI, I recently came across the book Animal Tracks of Minnesota & Wisconsin (Animal Tracks Guides). I didn't expect to find any information on tracks except mammal tracks. Surprisingly, the guide had an informative page on the tracks left by salamanders. The article states that salamanders leave a print of four toes from the fore foot and five toes on the hind foot print and often drag the belly and tail.

Three new salamander species were discovered in Costa Rica in the largest forest reserve in the Central America, La Amistad National Park. Discovered by a team led by Alex Monro of the Natural History Museum in London, all of the species found were small with the smallest, a member of the genus Nototriton, the size of a human fingernail. The other two species are members of the genus Bolitoglossa. None of the species have yet to be named.

In September of 2007 two new plethodontid species were found in the same area: Gomez’s Web-footed Salamander, Bolitoglossa gomezi and Brame’s Web-footed Salamander, Bolitoglossa bramei.

I had a phone call today from a fellow volunteer monitor. Out on a walk at a local nature center in Murfreesboro, Tennessee, she took the occasion to check for salamanders and first try, found a Slimy Salamander. I am not sure if this was an attempt to rub it in my face that while they are enjoying 75 degrees in Tennessee, temperatures are roughly 60 degrees colder here in Wisconsin/Minnesota. Any opportunity for finding a salamander is many months away for me.

I come across these three American researchers consistently as I review amphibian (particularly salamander) research and read of discoveries of new salamander species. I've based many of the posts in this blog on information from these researchers so some recognition was due.

My list of the top salamander researchers in the USA:

• Andrew Blaustein, Oregon State University
  An expert on amphibian declines, Dr. Blaustein is consistently interviewed magazines such as Nature and Discover.
  


• David Wake, University of California at Berkeley
  Every time I turn around he seems to be discovering a new species. He recently described two new species Costa Rican salamander species.
  


• James Petranka,The University of North Carolina at Asheville
  Dr. Petranka is the author of the Handbook of Salamanders, the massive handbook describing the plentiful salamanders species found in North America.
  

Back in February of 2007, multiple articles were published on the attempts to stimulate limb regrowth in humans by using extracellular matrix from pig bladders. A recent study has gone a step farther detailing the isolation of the entire TGF-beta 1 gene in Axolotls. The TGF-beta 1 gene stimulates the regrowth of lost limbs in Axolotls. Humans have this gene but our cells produce scars instead of inducing regeneration. While application of the extracellular matrix reduced scarring and infection, the isolation of the TGF-beta 1 gene provides the possibility that manipulation of this gene could result in limb regrowth in humans.

In May of 2005, I blogged about the discovery a new species of salamander Karsenia koreana. The discovery was important since most (98%) of the known species within the family Plethodontidae are found in North America. Karsenia koreana seemed out of place. A new study has investigated the genetic relationship of Karsenia koreana to 36 other salamanders in the family Plethodontidae. The study theorizes that Karsenia koreana is a descendant of North American plethodontid salamanders and may have moved across a Bering land bridge during a period of global warming. I doubt salamanders often make it into the NY Times but this news must be big since the NY Times has an article on it.

Updating a Jan. 6, 2006 post on salamanders losing the state amphibian race to frogs, I found out today that Senator Timothy Grendell from Ohio has introduced Senate Bill 240 to name the Spotted Salamander, Ambystoma maculatum, as the state amphibian.

The Toledo Blade reported on Oct. 22, 2007 that a Slimy salamander, Plethodon glutinosus, at the Toledo Zoo has laid 18 eggs in the first, and maybe only, time that they have been bred in captivity. The Toledo Zoo website had no other information on the event but did have information on Frogtown, the section of the zoo where the Slimy salamander is housed along with 9 other species of salamanders. The Toledo Zoo not only displays the salamanders and other amphibians to the public but participates in programs to protect and preserve amphibian species.

Two researchers, Benjamin M. Fitzpatrick and H. Bradley Shaffer, have reported in the September 20, 2007 issue of the Proceedings of the National Academy of Sciences(PNAS) on the discovery of inbreeding between California Tiger Salamanders and Barred Tiger Salamanders and the resulting hybrid which outcompetes the native California Tiger Salamander. The article "Hybrid vigor between native and introduced salamanders raises new challenges for conservation" looked at the composition of species surviving in California ponds and found that the hybrid species were more numerous than either of the other two species. The implications of the findings of this study present could be enormous. The California Tiger Salamander is endangered and been the focus of numerous lawsuits and government actions.

Slate Magazine has an interesting article on the relationship of genome size and the ability to fly. The genome size of different dinosaur species and the species that eventually evolved from those species were analyzed and the species that evolved with a smaller genome were the species that developed an ability to fly. The article mentions the large genome (all the genetic information found within an individual) of a salamander especially in relationship to a bird (the salamander genome is 90 times bigger). A large genome requires a large nucleus and thus larger cells. Larger cells lead to less transfer of gases in and out of the cells. Species that fly require a high metabolism and smaller cells that allow a much better transfer of gases. Thus a salamander crawls on the ground and a robin flies above it.
But why so large a genome in salamanders? No one knows. It is known that most of the DNA found in salamanders is classified as junk DNA as it doesn't code for a protein but what it does or does not do (maybe it was useful to the species in the past but isn't anymore?) is still being discovered. The Animal Genome Size Database collects data on genome sizes and produced the graph above clearly showing that the larger genome of salamanders. As far as rankings are concerned, salamanders are not number one, but do occupy the second and third place with the aquatic salamanders Necturus lewisi and N. punctatus followed by Necturus maculosus and Amphiuma.