Presentation on theme: "Silvery Salamander Presented By: Ellen Klocker Common Name: Scientific name:"— Presentation transcript:
Silvery Salamander Presented By: Ellen Klocker Common Name: Scientific name:
NAME: Silvery Salamander ALIASES: Ambystroma platineum SEX: All female species LENGTH: 17 cm long BUILD: Long, dark, slender body. COMPLEXSION: Blue lichenlike flecks over head and body. DISTINGUIDHING FEATURES: Lower jaw does not protrude beyond upper jaw. PLACE OF BIRTH: Vermilion County LAST RESIDENCE: Shallow vernal ponds in mesic oak-sugar maple-beech forest. FAMILY MEMBERS: Blue-spotted salamander, slimy salamander, & the smallmouth salamander. STATUS: Only one natural population remaining. JEFFERSON SALAMANDER IMPOSTER !WARNING! ENDAGERED IN ILLINOIS
Silvery Salamander was Last Seen… The Silvery Salamander was last seen in Illinois in a state park in Vermilion County. This is the last known natural population of this species. The Silvery Salamander is known to live in deciduous forests that are near swamps and ponds.
Environmental Regions The Silvery Salamander did not originate in Illinois, but rather migrated from the east. It can be found in areas as far north as Nova Scotia, and in areas as far east as New York. In fact, the Silvery Salamander is actually a mixture or combination of two separate species, the Blue spotted salamander and the Jefferson salamander.
Problems Normally, when salamanders reproduce, the mother contributes 14 chromosomes, and the father the other half. However, the Silvery salamander is a hybrid organism that is the result of backcrossing and the hybridization of the Blue Spotted salamander and the Jefferson salamander species. The Silvery salamander is the result of both hybridization and backcrossing, which in turn resulted in a TRIPLOID organism. The Silvery salamander is the result of a fertilization mutation, where the egg of a Jefferson salamander did not divide, and instead joined its 28 chromosomes with a haploid sperm to produce a triploid salamander. (3n = 42)
The silvery salamander reproduces by laying masses of 15 eggs and attaching each to slender twigs underwater in breeding ponds. In this unique process of fertilization, the sperm of a similar salamander specie only stimulates the egg of the Silvery salamander. The males genes do not transfer, and therefore the Silvery salamanders are always observed as females. The Single Sex Lineage **NOTE** Nature normally selects against single sexed organisms, but the Silvery salamander has survived for 4 million years.
Threatened By Extinction The mortality rate for developing Silvery salamander embryos is nearly 80%. The breeding pond in which they lay their eggs occasionally dries out. They are composed solely of females, and therefore they are dependent on other species for their survival. The Silvery salamanders have very low genetic variability because there is not sexual fertilization.
Solutions In an attempt to save the species, advocates for the Silver salamander have tried to stabilize their breeding environment by monitoring the breeding ponds. The well-being of the other species in which the Silvery salamander is dependent upon has been taken into consideration. It is very difficult to breed these organisms in captivity because they are not sexually fertilized but rather stimulated to reproduce, and these factors are extremely difficult to duplicate in the laboratory. There are no plans to overcome the lack of genetic variability. No major organizations are taking drastic steps to preserve this specie because it is of abundance in other states.
Bibliography “Reptiles and Amphibians: Jefferson Salamander.” “Triploid evolution.” “Ambystoma platineum.” “Amphibians.” “Unisexual Ambystoma.”