Salamanders of the family Plethodontidae are a unique species as they are part of a group of amphibians that lack lungs. They survive because Plethodontid salamanders, commonly known as lungless salamanders, breathe entirely through their skin and the tissue lining in their mouths. Their skin and mouths must keep moist in order to respire, so they are only found in damp areas.
Another distinctive feature of lungless salamanders is the presence of the nasolabial groove - a slit extending from the naris (nasal opening) to the upper lip. The groove is lined with glands and enhances the salamander's chemoreception (ability to detect chemicals in area). Outside of these interesting features, these salamanders are like any other family of salamanders with four limbs and 4-5 digits on the forelimbs and hindlimbs. For many salamander species eggs are laid on land, and the young hatch already possessing an adult body form.
Lungless Salamanders of Indiana
There are several lungless salamanders found in Indiana, mostly in the southern region in a variety of habitats including forests, streams and caves. They are likely found beneath logs or underneath rocks, and will only venture out of their hiding places in humid weather.
Common lungless salamanders in southern Indiana include:
- Eastern red-backed - distinguished by the red to red-orange stripe running from the head to tail; sides are dark, often with gray-blue spots.
- Long-tailed salamander - tail accounts for nearly two-thirds of salamander's length; usually yellow but ranges from reddish brown to orange with a series of small black spots over its body; able to regenerate its own tail.
- Northern dusky - yellowish brown to dark brown in color with gray - light brown underside; stout in stature
- Northern slimy - named for the fact that it releases a slimy, sticky substance when handled; is black with scattered flecks of white over its body.
- Northern zigzag - known for its red, orange or yellow stripe broadly zig-zagged over back; orange marks are found around the base of its front legs.
- Southern two-lined - small, slender, vary in color (bright yellow to rusty orange) with two long black stripes that run down head to tail.
Less common lungless salamanders in Indiana are:
- Cave salamander - grows to about 7 inches long; range from yellowish orange to bright red with dark irregular spots covering its body; underbelly is yellowish and without spots; incredible climber.
- Four-toed salamander - (a species of special concern in Indiana) - one of Indiana's smallest salamanders growing to about 3 inches long; has only four toes on its hind legs.
Unfortunately for them, it is man who is responsible for polluting and destroying their wet habitats. Filling in ponds, pesticide-use, and rerouting water for our own water needs has caused declines in many salamander populations. The Nature Conservancy, as well as other local and federal agencies, is committed to conserving remaining habitats for species, such as these salamanders, who need clean water to survive.