Salamanders in Frederick County
In damp forested areas of Frederick County, especially under leaf litter, logs or rocks, you will likely find a salamander, often a Yellow Spotted Salamander (Ambystoma maculatum), or one of a half dozen other salamander species, including Northern Two-Lined Salamander (Eurycea bislineata) and the Jefferson Salamander (Ambystoma jeffersonianum ). Of over 600 species of salamanders world-wide, a third are native to the habitat of the Appalachian mountain region. Ponds and wet areas, especially vernal (seasonal wetland) pools are natural breeding areas for salamanders. Vernal pools contribute the most to species survival of salamanders and other amphibians, due to the absence of fish, major aquatic predators of salamander eggs.
A Northern Two-lined Salamander commonly found in Frederick County
Spotted salamanders are approximately 5 to 8 inches in length as adults, with dark, bodies, having yellow spots. Northern Two-Lined Salamanders are small, typically about 4 to 5 inches in length, with brownish bodies having yellow streaks along the back and sides. Jefferson salamanders are about 5 to 7 inches long, with dark bodies often with blue or silver spots along the side. The eggs of these and most other salamanders in our area are deposited in gelatinous-like clumps on underwater plants or twigs in the early spring. The eggs hatch in less than a month to 2 months, depending on species, with the larvae maturing in 2 to 4 months. The gelatinous-like protective layer over the eggs not only helps keep the eggs moist, but also contributes to development of the embryos. A symbiotic relationship has been found between the yellow spotted salamander and a green algae called chlamydomonad algae (Oophilia amblystomatis), with the the translation of the Latin name meaning “loves salamander eggs.” The algae grows in the egg capsule metabolizing carbon dioxide and creating oxygen through photosynthesis for embryo development.
Larvae are hatched with gills, and for most species, loose these gills as lungs develop over a 2 to 4 month period while growing to adult form. Salamanders breed at approximately 2 years, and generally return to the same vernal pools from which they hatched. It's not hard to understand that draining wetland areas and vernal pools can disrupt the lifecycle of many amphibian species. Salamanders survive the winter by burrowing underground below the frost layer.
Salamander skin feels wet and sticky. Mucus glands in the skin help protect the animals from bacteria and molds, help make salamanders harder to catch by predators, such as birds, snakes and small mammals, and also help to regulate body temperature. Other glands on the head, back and tail secrete toxins that range from being bad tasting to potent irritants. The yellow spotted salamander, for example, exudes a whitish liquid when handled that irritates predators. Salamanders are nocturnal, feeding on small invertebrates including insects, worms, and slugs.
Like frogs, salamanders lack ear drums but have an inner ear that can detect low frequency sounds and vibrations, that can be picked up from the ground and and communicated through its limbs. They are found to detect sound in the range of about 500 Hertz which can provide warning of an approaching predator.
A salamanders eyes are mainly adapted for night vision. An enhanced sense of smell helps to compensate for weaknesses in other senses. A salamander's ability to smell typically includes not only the nose, but cell structure around the mouth. Science indicates the extended olfactory areas of smell not only help identify prey, but also help salamanders recognize other salamanders during courtship.
Salamanders are leaders in the animal world in the ability to regenerate limbs, when lost from injury. Salamanders can regenerate tails, limbs and feet fairly routinely. They have even been found to regenerate parts of internal organs. Special cells just beneath the skin have the ability to develop into any kind of cell. Stem cell research in mammals has in part focused on finding and applying similar cell regenerative capabilities in higher organisms and humans.
Article by Tom Anderson, FCFCDB member
Nature Note for 6/15/14