• At a time when amphibians are under threat worldwide, the marbled newt (Triturus marmoratus) is faring better than many. They are found commonly throughout the Iberian Peninsula in Spain and Portugal and in southern, western, and central France, though they are locally endangered in some areas of central France. They are also found sporadically in northern France where they share habitat with the northern crested newt. The two species can crossbreed when in the same body of water, creating hybrids.

    Like all amphibians, marbled newts require water for part of their life cycle. They are usually found in ponds, pools, and streams with extensive vegetation because females attach their eggs to aquatic plants. They favor woodlands, though they can also be found in heather and fields. They can live at altitudes from sea level to up 2,100 meters (6,800 feet) in elevation.

    These large newts have a distinctive appearance. Their skin has a green-and-black marbled pattern, and they have a dark line through their eye. During their aquatic phase, the males also develop a green-and-black-striped crest on both their upper body and near their tail. The females and young have a bright orange stripe along their spine.

    The interesting appearance of the marbled newt has led to them being collected and sold as pets, even though they are protected in Spain, Portugal, and France. Like other amphibians, they are also threatened by habitat destruction, water pollution, and disease. Arable land is encroaching on their habitat, although they can sometimes survive in the modified environment of traditional farmland. Non-native species, particularly some kinds of fish and crayfish, can also be a problem for the newts. They can bring disease that the newts are not equipped to fight off, and some are new predators that will eat the newts. Though the marbled newt is not yet considered vulnerable through most of its range, protections are in place and populations are being monitored to ensure that the species remains stable.

    1. What are some characteristics of amphibians like the marbled newt? 

      Amphibians are cold-blooded and undergo metamorphosis, most spending part of their life cycle on land and part in water. In their larval stage, they have gills, but in the adult stage, they exchange gases directly through their skin or through lungs. As adults, they absorb water through their permeable skin, which can dry out quickly out of the water. They lay eggs that do not have a shell.

    2. The marbled newt can crossbreed with the northern crested newt when they are in the same body of water. What does this mean, and how might it affect these species?

      Crossbreeding is when one species breeds with a different species. Crossbreeding leads to the birth of hybrids. Hybrids are often less viable than the offspring of the individual species, so they can affect the populations of both species. Hybrids can also have an appearance and other characteristics that are different from the parent species. 

       

    3. The marbled newt is not considered threatened throughout most of its range. Why are there still protections for these animals?

      Protections are in place to ensure that these animals do not become endangered. They are designed to monitor the newts and to protect against known threats to keep the population levels healthy.

  • Term Part of Speech Definition Encyclopedic Entry
    amphibian Noun

    an animal able to live both on land and in water.

    aquatic Adjective

    having to do with water.

    arable Adjective

    land used for, or capable of, producing crops or raising livestock.

    crest Noun

    decorative tuft on the head of a bird or animal.

    crossbreed Verb

    to produce or influence the production of an organism from organisms of two different breeds or varieties of the same species.

    heather Noun

    evergreen plant that occurs in northern or alpine regions.

    hybrid Noun

    the end result of two different sources of input.

    sporadic Adjective

    occasional and happening in isolated instances.

    vegetation Noun

    all the plant life of a specific place.

    vulnerable species Noun

    level of conservation between "near threatened" and "endangered." Vulnerable is the lowest of the "threatened" categories.