Blue-spotted salamanders have a long tail and slim body. Their feet have relatively long toes (Conant and Collins 1998). They are given their name for the bluish-white spots and flecks on the sides of the body and tail and also sometimes on the back. Their skin is bluish-black (Conant and Collins 1998). The spots are also on their limbs and belly (Harding 1997). The belly may be either black or a lighter shade than the dorsum, but the vent is usually black (Harding 1997). There is some size difference between the males and the females. The males tend to be smaller than the females; the males also have a longer more flattened tail (Harding 1997).
When the larvae are small and young they have tail fins and external gills for living in the water (Collicutt 1999). But once they have developed all four legs they appear to be dark brown, olive or gray in color.
Blue-spotted salamanders are found from eastern central North America and stretch in a broad band across to the Atlantic Provinces and northern New England. They are found around the Great Lakes and west as far as central Manitoba. They reach as far north as James Bay, Ontario (Collicutt 1999).
Blue-spotted salamanders are found mostly in moist woodlands with sandy soil. They differ from other salamanders in that they are found above ground throughout the warmer months (Harding 1997). During the day they stay out of the direct sunlight. They spend the summer and fall in damp forests, searching for food at night (Nova Scotia 1999).
The life span of a blue-spotted salamander is unknown. Both male and females become adults at about 2 years of age. The salamander breeds in woodland ponds and ditches. They breed in April in small ponds. The female lays as many as 500 eggs attached to underwater sticks, plants or rocks. The eggs take about 1 month to hatch. The young salamander larvae have gills, and a large tail fin. At two weeks old, the front legs form and at 3 weeks the hind limbs are formed. Between 3-5 cm in length they transform into the adult form and leave the pond. When they transform in the late summer, they loose their external gills and tail fins and develop their blue spots. (Collicutt, 1999; Conant and Collins, 1998; Minton, 1972)
Blue-spotted salamanders are nocturnal and hunt out earthworms and small insects from underneath rotting logs. After a warm rain, they can be found hunting on the forest floor free from cover. The small size of the body enables the salamander to hide well, and the blue spots help to break up the outline of the body. Glands on the tail produce a milky toxic liquid that is secreted when it is threatened. The blue-spotted salamander holds the tail up and curved over the body when it is frightened. If the predator attacks the tail, it gets the sticky secretion in its mouth. (Collicutt, 1999)
The Blue-spotted salamander is a carnivore. The adult eats worms, snails, slugs, insects, centipedes, spiders and other invertebrates. The larvae eat small aquatic invertebrates such as water fleas (cladocerans), copepods, insects and insect larvae, especially mosquito larvae (Harding 1997). The diet suggests that the feeding ground is beneath leaf litter in forests (Collicut 1999). In captivity, blue-spotted salamanders survive on 1 worm a week (Collicut 1999).
Blue-spotted salamanders consume many mosquitoes each year (Harding 1997).
Due to the loss of wetlands and the destruction of forests, the salamanders are threatened in many states. Michigan is one of the only states where blue-spotted salamanders are still very common.
The blue-spotted salamander can breed with the spotted salamander, the Jefferson salamander, and the tiger salamander, creating hybrids.
David Armitage (editor), Animal Diversity Web.
Melissa Donato (author), Michigan State University, James Harding (editor), Michigan State University.
"The Canada Centre for Inland Waters (CCIW)" (On-line). Accessed November 6, 1999 at http://www.cciw.ca/ecowatch/dapcan/tour/glossary/bss/bss2.htm.
Collicutt, D. 1999. "Nature North Zone" (On-line). Accessed November 6, 1999 at www.pangea.ca/nnz/spring/creature/bluespot/Fblspot.html.
Conant, R., J. Collins. 1998. Reptiles and Amphibians in the Eastern/Central North America. New York: Houghton Mifflin Company.
Harding, J. 1997. Amphibians and Reptiles of the Great Lakes Region. Michigan: The University of Michigan Press.
Minton, S. 1972. Amphibians and Reptiles of Indiana. Indiana: The Indiana Academy of Science.
Spolsky, C., C. Phillips, T. Uzzell. 1992. Gynogenetic Reproduction in Hybrid Mole Salamanders. Evolution, 46(6): 1935-1943.