That Reptile Blog – Reptile, Amphibian and Exotic Pet Care and Information

Spotted salamanders produce toxic skin secretions but are none-the-less consumed by garter snakes and hog-nosed snakes. Introduced trout, bass, goldfish and other fishes prey upon the larvae and can decimate a population in a single season.

Reproduction
Adults migrate from terrestrial burrows to temporary ponds (vernal pools, swamps, ditches, sluggish streams) in the early spring. The migration is triggered by snow-melt or warm rains, with adults sometimes crossing snow to reach their breeding sites. Males arrive at the ponds 1-6 days before females. I have observed them breeding in Westchester County, NY in mid March, when the water is quite cold. Despite this, I found that food for the larvae, in the form of aquatic insects and fairy shrimp, was abundant.

Large mixed-sex groups form at the pond bottom during courtship. Males deposit a spermatophore (a sperm-filled, jelly-coated capsule) on the pond bottom. The females take this into their cloaca (reproductive opening) and fertilization occurs internally.

The eggs are laid in compact, jelly-covered masses that are attached to twigs, plants or sunken logs. Each mass contains 50-160 eggs. The sight of 20 or more large, brilliantly marked salamanders writhing together in as they vie for breeding rights is really something to see – please write in if you’d like information as to how you might observe this for yourself.

A species of green algae, Oophila amblystomatis, frequently colonizes the egg mass, apparently supplying oxygen to the embryos and utilizing the carbon dioxide that they produce. Larvae from algae-colonized egg masses hatch earlier and exhibit less mortality than do those from algae-free masses.

The adults return to their burrows after breeding. The terrestrial habitat may be 75 – 1,000 feet from the breeding pond.

The larvae hatch in 8-60 days, depending upon water temperature, and have external gills. Transformation to the adult form takes place over a period ranging from 6 weeks to 18 months. In NY, the larvae typically leave the breeding ponds by late July or August, after which the ponds usually dry up.

Miscellaneous
Adult spotted salamanders have lungs but rely largely upon cutaneous respiration (the absorption of oxygen through the skin). The skin must remain moist if this form of respiration is to be effective – they are therefore, limited to damp habitats and rarely appear above ground except after heavy rains. They and other salamanders depend upon protective tree cover, leaf litter and fallen logs to retain soil moisture, and rapidly disappear from degraded habitats.

You can read more about spotted salamander natural history and conservation at:
http://www.globalamphibians.org/
Of course, you can also order my salamander book from That Pet Place (see above) – Thanks!

In contrast to frogs, salamanders reach their greatest diversity in temperate habitats – more species are found in the eastern USA than anywhere else on earth. Today I would like to take a look at the natural history of the spotted salamander – a large, local beauty that makes both an excellent “first salamander” and a fine addition to advanced collections. Next week I’ll cover their care in captivity.

Physical Description
Varies in length from 4 ¾ to 9 ¾ inches. Stoutly built, with a black or slate- colored body marked by irregular rows of brilliant yellow (occasionally orange) spots. Larvae are usually a uniform olive or brown in color with bushy red external gills.

Range and Habitat
Eastern and central North America – from Nova Scotia and central Ontario, Canada south to Georgia and west to eastern Iowa and eastern Texas. They are absent from southern NJ and the Delmarva Peninsula. Isolated populations are still to be found within NYC, on Staten Island and in Queens and the north Bronx.

Spotted salamanders favor deciduous lowland forests and meadows near forest edges and sometimes inhabit woodland patches within suburban areas. Adults require soil into which they can burrow and the fish-less bodies of water for breeding (the larvae are relatively defenseless against fish). Certain populations breed where fishes are present, but only if dense aquatic plant cover is available.

Spotted salamanders are members of the family Ambystomatidae – the mole salamanders. True to this name, the terrestrial adults spend most of their lives below logs or underground in self-excavated burrows or in those dug by mammals such as moles, shrews and field mice. They have been found at depths of 4 feet below ground, and generally forage on the surface only on damp or rainy nights. Spotted salamanders are sensitive to soil pH and avoid acidic soil.

Status in the Wild
Common in some parts of the range and drastically declining in others due to habitat loss – the removal of trees causes the soil to dry, and results in loss of the protective leaf-litter cover needed by this species. The introduction of trout and other game fish to breeding ponds quickly causes local extinctions.

Spotted salamanders typically breed in vernal (temporary) ponds, which are often small in size and only a few inches deep (these lack fish – see above). Unfortunately, such “puddles” are rarely recognized as worthy of protection, and hence are destroyed at a greater rate than are other habitats.

They are also threatened by acid rain and road-salting, both of which change soil and breeding pond pH, killing the larvae and driving off the adults. Protected by several states but not nationally, and not listed by CITES.

Another amphibian that breeds in early spring is the strikingly marked spotted salamander, A. maculatum. Reaching 9 ¾ inches in length, these stout animals are jet black with yellow spots, and have been observed crossing snow during breeding migrations (I find them in ponds in southern NY in mid-March).

Amazingly, a species of green algae, Oophila amblystomatis, colonizes the spotted salamander’s globular egg masses. The algae most likely utilizes carbon dioxide and ammonia produced by the developing salamander embryos, and may in turn provide the embryos with oxygen (although the amount released is quite low). There is speculation that the algae may produce a growth factor that benefits the embryos, but more research is needed. In any event, experiments have shown that egg masses with this algae hatch faster, and with a higher survivorship, than do those lacking the algae. Conversely, algae growth slows markedly if the embryos are removed from the egg mass upon which it is established.

Spotted salamanders make interesting pets, and, while adapted to a burrowing lifestyle, adjust well to life above ground. Properly cared for, they can live for over 25 years. I will discuss them further in a future article.

More detailed information on this unique relationship is available at:
http://jeb.biologists.org/cgi/reprint/197/1/17.pdf