Newt - biology.
Publié le 06/12/2021
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Newt - biology.
Newt, common name applied generally to certain members of a family of relatively small salamanders, most of which spend at least part of their lives in water. The
many species are widely distributed throughout the temperate regions of the northern hemisphere. Newts often are brightly colored and active, and most are about 8
to 14 cm (about 3 to 5.5 in) long.
One of the most familiar species is the common red-spotted newt of the eastern and central United States. The adult is olive or tannish-green, spotted on the sides with
red surrounded by black; the belly is yellow with small black dots. This salamander lives in thickly vegetated ponds and streams and feeds on aquatic snails and insects.
The female attaches its sticky eggs to aquatic plants; the eggs are deposited singly. The newly hatched larvae are equipped with gills that become rudimentary when
the larvae are about 2.5 cm (about 1 in) long. At this point, the larvae, which are known as red efts because they are bright reddish-orange with black spots, leave the
water and spend the next few years on land in damp, wooded regions. They eventually return to the water, develop the adult coloration, and remain in an aquatic
habitat.
Another common American species is the California newt, which grows to more than 15 cm (6 in). Common European species include the smooth newt; the crested
newt, the male of which develops a crest during the breeding season; and the palmate newt.
Predators avoid many species of newts because glands in the newts' skins produce toxic secretions. However, some populations of garter snakes in western North
America have evolved the ability to feed on species of newts that are lethal to much larger predators.
Scientific classification: Newts belong to the family Salamandridae. The common red-spotted newt is classified as Notophthalmus viridescens, the California newt as
Taricha torosa, the smooth newt as Triturus vulgaris, the crested newt as Triturus cristatus, and the palmate newt as Triturus helveticus.
Microsoft ® Encarta ® 2009. © 1993-2008 Microsoft Corporation. All rights reserved.
Newt - biology.
Newt, common name applied generally to certain members of a family of relatively small salamanders, most of which spend at least part of their lives in water. The
many species are widely distributed throughout the temperate regions of the northern hemisphere. Newts often are brightly colored and active, and most are about 8
to 14 cm (about 3 to 5.5 in) long.
One of the most familiar species is the common red-spotted newt of the eastern and central United States. The adult is olive or tannish-green, spotted on the sides with
red surrounded by black; the belly is yellow with small black dots. This salamander lives in thickly vegetated ponds and streams and feeds on aquatic snails and insects.
The female attaches its sticky eggs to aquatic plants; the eggs are deposited singly. The newly hatched larvae are equipped with gills that become rudimentary when
the larvae are about 2.5 cm (about 1 in) long. At this point, the larvae, which are known as red efts because they are bright reddish-orange with black spots, leave the
water and spend the next few years on land in damp, wooded regions. They eventually return to the water, develop the adult coloration, and remain in an aquatic
habitat.
Another common American species is the California newt, which grows to more than 15 cm (6 in). Common European species include the smooth newt; the crested
newt, the male of which develops a crest during the breeding season; and the palmate newt.
Predators avoid many species of newts because glands in the newts' skins produce toxic secretions. However, some populations of garter snakes in western North
America have evolved the ability to feed on species of newts that are lethal to much larger predators.
Scientific classification: Newts belong to the family Salamandridae. The common red-spotted newt is classified as Notophthalmus viridescens, the California newt as
Taricha torosa, the smooth newt as Triturus vulgaris, the crested newt as Triturus cristatus, and the palmate newt as Triturus helveticus.
Microsoft ® Encarta ® 2009. © 1993-2008 Microsoft Corporation. All rights reserved.
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