Marbled Salamander
Ambystoma opacum
Summary: A handful of records from Porter and LaPorte Counties, Indiana, the most recent in 1953. Extensive searches of wooded land in the vicinity of the Smith (LaPorte County) locality in 1999 failed to locate this species. All of the Chicago region historical localities are within the snowbelt southeast of and within a few miles of Lake Michigan, and are widely disjunct from the main body of the range, located more than 150 miles to the south.
Description: A small but robust salamander, 3.5 to 5.0 inches (9.0-12.7cm). Black above and below, with large and distinct light gray (females) or white (males) crossbands over the upper surfaces.
Distribution and Status: The marbled salamander is known from a few localities near the eastern limit of the region. All of the records are old, and it is uncertain whether marbled salamanders still survive here. The most recent report, in 1951, was near Tremont in Porter County, and there are also 1932 and 1947 records from the dunes area. Three LaPorte County specimens from the vicinity of Smith date to 1940; I have been able to identify the approximate collecting locality, but searched the area for several days in the fall of 1999 without success. There are also records from nearby Berrien and Allegan Counties, Michigan. All of these localities are in the snowbelt along the southeastern margin of Lake Michigan, where in winter precipitation is high and temperatures slightly moderated. The marbled salamander is a southeastern coastal plain species, and Chicago region populations are more than 150 miles disjunct from the main body of the range.
Habitat: Elsewhere in the range, marbled salamanders inhabit a variety of upland and bottomland forest. In the Missouri Ozarks, mature floodplain forest supports the largest populations.
The Porter County locality is within seasonally inundated red maple forest. The LaPorte County locality is a mosaic of beech-maple forest and wet flatwoods. The Berrien County record is in floodplain forest.
Phenology: Marbled salamanders are unique among local Ambystoma because they breed on land in the fall. Adults migrate to dry pond basins with the first cooler temperatures and during or immediately after rainfall. Bishop (1941) described the courtship. Eggs are deposited under logs, leaf litter, or other debris, and the female usually guards the nest until the eggs are inundated by rising pond levels. South of Indianapolis we found numerous females guarding eggs in late September; further southwest in the Ozarks males were just arriving at ponds in early October. Presumably breeding begins on average by mid-September in our more northern location, but considerable annual variation depending on weather must occur.
Eggs hatch shortly after inundation. Because of the fall breeding season, larvae have a growth advantage over spring breeding Ambystoma in the same pond, and marbled salamander larvae frequently prey on the other larvae. In exceptionally cold winters ponds may freeze, killing all overwintering larvae.
No local information is available on time of metamorphosis, but in New York it occurs in May and June (Bishop, 1941).
Literature Cited
Bishop, S. C. 1941. Salamanders of New York. New York State Museum Bulletin 324:1-365.
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| Updated: October 9, 2007
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