Blue-spotted salamander
Blue Cross dental stains Newt ( Ambystoma laterale)
Called The Blue stain - toothed cross- Newt ( Ambystoma laterale), also Blaupunkt cross tooth scraper, a common salamander in eastern North America from the family of transverse tooth newts is ( Ambystomatidae ). Within the family and genus, it is the most northerly occurring species.
Features
Adult animals reach a total length of 8-14 centimeters. The males remain slightly smaller than the females and have a slightly longer tail in relation to the hull. The rather broad-headed and elongate salamanders have the segmented by 12 to 14 ribs furrows hull in blue- blackish ground color on a color pattern from blue and white spots ( upper side ) and corresponding points on the flanks. The belly is pale and contrasted so with the dark top.
Distribution, habitat, life style
The blue stain - cross pig tooth comes in the northeastern states of the United States ( around the Great Lakes, New England, etc.) and southeastern Canada in the provinces of Ontario and Quebec before. Mainly, the populations are north of the so-called Wisconsin Glaziallinie ( Vergletscherungsgrenze the last ice age ).
As terrestrial habitats moist deciduous forests and swampy bushland are preferred; but there are also deposits in coniferous forests. During the day the animals hide under dead wood, fallen leaves or rocks to go at dusk and at night foraging for insects, worms, snails and spiders. Overwintering takes place on land in frost shelters. As reproductive waters serve temporarily water-bearing small bodies of water such as ponds and ditches within forests that do not dry out too early, to ensure the larval development.
Reproduction and individual development
In the mating season in spring blue stain - toothed cross newts migrate to their spawning grounds. In the southern areas of distribution, this is the end of March / beginning of April the case further north later, sometimes up into June. Within a few days then finds the spawning events take place ( " explosive spawning "; see for example grass frog). A female produces an average of about 200 to 250 gallertumhüllte eggs per season. After fertilization by the male (compare: Cross Dental newts ) attaches the female spawning individually or in small tight clumps of two to 15 eggs on water plants.
After three to four weeks, the larvae hatch and are now entering a aquatile life. They feed mainly on small crustaceans and insect larvae. Two to three months after hatching occurs the metamorphosis; the further life takes place on land. After two years, the animals are finally mature - males are about 42 to 45 millimeters long at this time, females 51 to 52 millimeters - and participate in their part in reproduction.
Hybridization, gynogenesis
Blue Cross dental stains newts get along with other Ambystoma species (including the Jefferson - tooth cross- newt and the Eastern Tiger Salamander ) regularly produce hybrids. About 70 percent of all stocks should be associated with such hybrids.
As a zoological peculiarity occasionally occur also unisexual, all-female populations, these females have clonally - triploid chromosome sets. Using the sperm of males of different species Ambystoma only to stimulate egg laying, but without the need for their genetic information ( chromosomes) and to serve. This phenomenon discovered in transverse tooth newts in the 1960s is also known as gynogenesis.
Endangering
The total population of this species is not currently considered threatened. In the Red List of the World Conservation Union, the Blue Cross dental stains pig is therefore considered " not at risk " out ( least concern ). In some States, however, the species is listed as endangered or even critically endangered. Reasons include the loss of natural forests and forest waters, clear-cutting in forests and acid rain which lowers the pH in the larval habitats below a critical limit ( about pH 4.5 to 5 ). The competition with unisexual populations ( see above) could inhibit its spread local " normal stocks ."