Caudata Ambystoma opacum -- Marbled Salamander
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Purple shade indicates vouchered specimens. Light blue (cyan)
shade indicates photographic records. Yellow shade indicates verified
sighting. Slanted hatch indicates pre-1980 records only
NOTE: Not all specimens upon which these maps are based have been verified.
Key Characters: Stocky, black or gray body with whitish crossbands on back and tail; belly black, sometimes with white flecks.
Similar Species: Adults not likely to be confused with any other salamander.
Description: Short (up to 12 cm TL), stocky salamander with grayish white (female) or bright white (male) crossbands on back and tail, sometimes incomplete, sometimes running together along sides. Before banded pattern develops on juveniles, the back is covered with scattered whitish or silvery frosting. Male has more protuberant cloacal region than female, especially during breeding season. Larva distinguished by uniform dark stippling on throat and sides of belly, and row of conspicuous clear spots on midsides.
Habitat: Mesic forests, dry hillsides, and moist floodplains. In autumn, adults migrate to wooded breeding areas, where they mate in dry pond basins or margins of ponds and swamps that will be flooded by autumn or winter rains.
Natural History: The largely subterranean adults are sometimes found under rocks and logs, especially during September-October, when they breed in dry pond basins. Each female lays 100-300 eggs in a loose cluster on land and curls protectively around them. The eggs hatch when covered with water from autumn rains. Larvae feed on microcrustaceans, insect larvae, snails, isopods, amphipods, and other aquatic invertebrates and transform the following April or May. Adults feed on beetles, centipedes, slugs, worms, and other invertebrates.
Status: Much suitable habitat remains in counties south of the Shelbyville Moraine, and some along the Vermilion River.