Short-headed Ambistoma (Ambystoma Texanum)

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Short-headed Ambistoma (Ambystoma Texanum)
Short-headed Ambistoma (Ambystoma Texanum)

Video: Short-headed Ambistoma (Ambystoma Texanum)

Video: Short-headed Ambistoma (Ambystoma Texanum)
Video: Small Mouthed Salamander - Ambystoma texanum 2023, November
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The Texas salamander, or short-headed ambistoma, lives in North America. They prefer wet places - river floodplains, fallen and decaying trees near water bodies and marshes, or fallen leaves. Uses burrows dug by other animals. In response to an attack by a predator, adult amphibians assume a defensive position. Leads a nocturnal lifestyle, hiding in shelters during the day. It eats various invertebrates. Reproduction takes place under water. Oviparous.

Area

North America - from the northeastern west of Ohio to Missouri and eastern Nebraska. The north of the range is southeastern Michigan; the south of the range passes through western Kentucky and Tennessee to the Gulf of Mexico.

Short-headed ambistoma (Ambystoma texanum), photo photograph tailed amphibians
Short-headed ambistoma (Ambystoma texanum), photo photograph tailed amphibians

Appearance

The body of the Texas ambistoma is large, stocky; the tail is long, rounded in cross section; the mouth is small, 2-3 rows of palatine teeth are located transversely - one behind the other; the head is small, wide with a blunt short muzzle; the lower jaw protrudes slightly forward. The eyes are small with movable eyelids. The limbs are thin. The front legs have four short toes, the hind legs have five. Costal grooves 14-16.

The skin is smooth. The diploid number of chromosomes is 28. Males are smaller in size than females, their tails are more compressed from the sides.

Color

Coloring from black or pale gray with light (gray or silver) spots on the back and sides, the belly is dark. During the breeding season, ambistomas become faded.

The larvae have light stripes on an olive green or dark brown background. Before metamorphosis, light stripes are replaced by dark spots. In general, the coloration of short-headed ambistas strongly depends on their habitats.

The size

Grow up to 10-18 cm.

Short-headed ambistoma (Ambystoma texanum), photo photography amphibians
Short-headed ambistoma (Ambystoma texanum), photo photography amphibians

Habitat

Ambistomas prefer wet places - river floodplains, fallen and decaying trees near water bodies and swamps or fallen leaves, agricultural land (near water), as well as meadows and prairies (near water bodies). Adult amphibians can sometimes be spotted on rocky slopes.

They use holes dug by other animals, incl. crayfish and small mammals. Evening rain sometimes prompts them to come to the surface.

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Enemies

Predatory aquatic insects, tiger salamander larvae, garters (Thamnophis) and American water snakes (Nerodia).

Food / nutrition

Adult short-headed ambistomas eat insects, slugs, millipedes, earthworms, butterflies and spiders. The larvae are versatile predators, they eat small aquatic invertebrates, including daphnia, isopods, crustaceans, as well as larvae of other amphibians and their own species.

In response to the attack of a predator, adult amphibians take a defensive position: they lower their heads, wriggle their bodies, raise and wave their tail (there are several glands on the tail that secrete a caustic substance).

Behavior

The Texas salamander is nocturnal, hiding in shelters during the day. During the breeding season, amphibians may congregate in small groups around water bodies. Adults in burrows wait out the hottest months of the year.

Social structure

Amphibians lead a secluded and secretive lifestyle, not territorial.

Reproduction

Short-headed ambistomas are oviparous, fertilization is internal. Eggs in separate bags are deposited by the female in stagnant or slowly flowing water bodies (temporary forest water bodies, roadside ditches, flooded areas, river swamps, etc.). The larvae are aquatic, in proportions and constitution, they are similar to adults.

Adult salamanders migrate to water bodies (without fish) in the dark or in rainy weather, where they lay eggs. Adolescents undergo post-metamorphic migrations.

Reproduction takes place under water. Males push females, rub against them, and then deposit spermatophores in the water (on branches or foliage). One male can deposit up to 128 spermatophores! Females take spermatophores into themselves (up to 26 spermatophores from different males), and then lay eggs in shallow water and usually attach them to branches and vegetation underwater. There is no amplexus.

Females lay eggs singly or in groups. In a year, one female can produce up to 300-700 eggs (1.6-2.5 mm in diameter), which she lays in small gelatinous masses of 3-30 eggs.

Season / period of breeding

Falls from January-February to April-March.

Puberty: short-headed ambistomas reach sexual maturity at a height of 6-7 cm (presumably in the second year of life).

Short-headed ambistoma (Ambystoma texanum), photo photograph tailed amphibians
Short-headed ambistoma (Ambystoma texanum), photo photograph tailed amphibians

Incubation of eggs

Lasts 3-8 weeks (depending on water temperature).

Offspring

Newborn Texas salamander larvae are 7-14 mm long. The larvae have thick gills, dark brown spots on the back, a slightly noticeable strip stretches along the sides.

Young larvae feed on cladocerans, ostracods, insects and their larvae, having matured a little, the larvae move on to isopods and gastropods. The larvae feed every day (day and night). They stick to the surface of the water (under floating debris) or at the bottom of the reservoir.

Metamorphosis begins at the age of 2-3 months. at a size of 40-48 mm (from late May to July). Within a few weeks after metamorphosis, young short-headed ambistomas migrate to wet places. Adolescents are more likely to hide in fallen leaves than adults.

Benefit / harm to humans

Texas salamanders eat various pests of forests and agricultural plantations - slugs and worms. Serve as food for blue jays and other animals.

Population / conservation status

Short-headed ambistomas are numerous throughout the range. This is due to the fact that these amphibians are found in quite a variety of habitats. The main threat to the species is the loss of moist areas that are needed for reproduction.

On salamanders, many protozoa and helminths parasitize. Short-headed ambistomas can interbreed with other Ambystoma species.

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