[Picture of San Marcos SALAMANDER]

Learn About The Threatened
SAN MARCOS SALAMANDER



SAN MARCOS SALAMANDER
SCIENTIFIC CLASSIFICATION


KINGDOM Animalia
PHYLUM Chordata
CLASS Amphibia
ORDER Caudata
FAMILY Plethodontidae
GENUS Eurycea
SPECIES nana
Common Name San Marcos salamander


SALAMANDER is the common name for about 320
species of Amphibians with tails. They include
all the members of the order Caudata, including the
newts (family Salamandridae).
Salamanders occur mainly in the temperate regions
of the Northern Hemisphere.
They do not occur in Australia or south of the
Sahara in Africa, and are rare in South America.

The name Salamander is derived from an old Arab\
Persian word meaning "lives in fire", stemming from
an old false belief, that the salamander could walk
through fire and remain unharmed.

As members of the Amphibians' class they are
"cold-blooded" vertebrate animals.
Amphibian means "two lives," a reference to the
metamorphosis they go through.
The tadpole, the larval stage of aa amphibian, is
usually an aquatic plant-eater with gills and a long,
finned tail.
The tadpole lacks legs and swims by moving in a
wave-like fashion like its fishlike ancestors.
During the transformation (metamorphosis) that leads
to the "second life," legs develop and the gills disappear.
The young tetrapod crawls onto shore and begins its
life as a terrestrial hunter.

Salamanders are a very old group that diverged early
from the other amphibian stocks.
Many scientists suggest that the ancestors of modern
salamanders are among the lepospondyls.
The order Caudata includes all the salamanders.

The most abundant family, containing about 200
known species of salamanders, is the Plethodontidae.
It evolved in the Appalachian Mountains of the United
Sates and has many species throughout North America.
It has a group of species that has invaded Central
America and radiated extensively, and two species in
Europe. This family contains burrowing, tree-living,
stream-dwelling, and terrestrial species.


GENERAL CHARACTERISTICS OF SALAMANDERS:
  • Salamanders range from the smallest at about
    5 cm (2 in) to the largest, the giant salamander,
    Andrias japonicus that may be up to 180 cm (70 in)
    in length and about 25 kg (55 lb) in weight.
  • Salamanders externally are characterized by
    having short bodies with long tails, 4 legs with
    clawless toes and well-developed heads, with large
    mouths and eyes.
  • The skin is usually smooth and moist and
    without scales or external ear openings.
  • They are brightly colored, often brown, black,
    yellow, or red, and usually have light or dark spots,
    bars, or stripes.
  • They are deaf to airborne sounds but hear or
    feel by sensing vibrations from the ground.
  • They have relatively good vision but have little
    or no voice production.
  • Salamanders have a keen sense of smell and
    taste largely attributed to their sensitive tounges,
    packed with various types of nerve endings.
  • Their mouths contain small teeth implanted on
    the margins of the upper and lower jaws and in
    some cases the roof of the mouth.
  • Their skin contains many glands, some
    secreting mucus to help maintain moisture and
    others secreting a toxic or irritating substance
    when the animal is frightened.
  • Salamanders molt their skin, from every few days
    to every few weeks, depending on the species and
    except in very cold weather, when it ceases
    completely.
  • They do not hibernate as they do not have the
    required mechanisms found in warm blooded animals
    to support the process.
  • They have the amazing ability to shed their
    tails and grow them back, as well as regenerate other
    damaged or severed parts of their body.
  • Salamanders swim like eels, using body muscle
    contraction to propel themselves through the water.
    They use their limbs very little in swimming.
  • On land, the limbs give considerable propulsion
    to the body. They walk one leg at a time in a diagonal
    pattern. The limbs are sprawled out from the body,
    and the middle of the trunk usually rests on the
    ground.
  • They have a three-chambered heart and its
    respiratory system involves gills in the larvae stage
    and lungs in the adults.
  • Oxygen intake can also occur through the skin
    and the mouth membranes.
  • Water is absorbed through the skin. Hence the
    need for a cool moist environment.
  • They may live permanently in freshwater(aquatic),
    part of the time in water (as larvae and to breed)
    (semi aquatic), or entirely on land(terrestial).
  • Most adults hide by day and feed at night, some
    emerge only when moisture and temperature levels
    are suitable.
  • They are nocturnal and carnivorous,feeding on
    insects, worms, and other similar small prey, and
    even other salamanders.
  • Salamanders can have a life span of from 1 to 60
    years depending on the species.


CHARACTERISTICS OF THE SAN MARCOS SALAMANDER:
  • The SAN MARCOS SALAMANDER is a
    member of the Plethodontidae family of lungless
    salamanders known as brook salamanders.
  • It is a neotenic species retaining its gills
    throughout its life.
  • This salamander sexually matures in the water.
  • Its name "nana" comes from the Greek "nanos" or
    Latin "nanus" meaning dwarf and referring to the
    small adult size of these salamanders.
  • The species was first collected for scientific
    purposes from San Marcos Springs on June 22, 1938
    by C.E. Mohr.
  • It was then described as "a small, slender,
    neotenic species uniformly light brown above with a
    dorso-lateral row of pale spots on either side of
    the mid-line; yellowish white below; with 16 to 17
    costal grooves".
  • The San Marcos salamander is light brown with
    small yellow spots arranged in a row down each side
    of the back.
  • Its size is from 1 1/2 to 2 inches.
  • It has a slender body and limbs.
  • Its eyes are small with dark rings around them.
  • They have light-colored external gills and finned tail.
  • They have four toes on the front feet and five
    toes on the hind feet.
  • They have from sixteen to seventeen costal grooves.
  • Its ventral surface is translucent, pale yellow.
  • This salamander is strictly aquatic. It may be seen
    among algae in the spring-fed pool at head of the
    San Marcos River.
  • They eat Tiny aquatic crustaceans, aquatic insects
    and snails.
  • It occurs only in Spring Lake and an adjacent
    downstream portion of the upper San Marcos River.
  • It is found only in Hays and Blanco Counties of Texas.
  • Moss and algae provide hiding places for the
    salamanders and habitat for small animals that serve
    as their food.
  • The dark reddish-brown color of the algae almost
    perfectly matches the dark color on the back of the
    San Marcos Salamander.
  • They do not occur where the bottom is muddy or bare.
  • Clean, clear, flowing water of constant temperature
    is required for suitable habitat.
  • The females lay her eggs singly or in small groups,
    which are attached to plants or under the rocks.
  • This aquatic salamander has external gills which
    are retained throughout life.
  • This species has value as a component of Texas'
    natural heritage of biotic diversity.


WHY ARE THESE SALAMANDERS
THREATENED???
  • These salamanders were listed as Threatened in 1980.
  • The reduction in the flow of water from the
    springs is the greatest threat to the survival of
    the San Marcos Salamander.
  • The growth of cities has led to higher water use
    by people.
  • The City of San Marcos is growing rapidly.
    Increased urbaniziation causes increased flooding
    (due to uncontrolled runoff), pollution, siltation,
    and general decrease in species diversity, and species
    numbers in adversely impacted aquatic environments.
  • Urban pollutants such as locally applied fertilizers,
    pesticides, and herbicides also may be negatively
    impacting on the San Marcos species.
  • The survival of this (threatened) and three
    endangered San Marcos River species (San Marcos gambusia,
    fountain darter, and Texas wild rice) is tied to the
    survival of the San Marcos River ecosystem. If the flow
    of the San Marcos River, with its natural cycle of
    variation, is assured, the chances of the long-term
    survival of these species increase.
  • The increased water pollution and silt accumulation
    is another problem.
  • The introduction of non-native species is also
    a threat because they may destroy aquatic vegetation,
    prey on endangered animals, or compete with them for food.



TO HELP PROTECT THE
SAN MARCOS SALAMANDER
  • It has been designated a Threatened species
    pursuant to the Endangered Species Act of 1973
    (50 CFR 17.11; P.L. 93-205, 87 Stat. 884; 16 U.S.C.
    1531-1540), as amended.
  • The species has this status wherever found
    including the State of Texas.
  • Critical Habitat has been designated in Spring
    Lake and its outflow, the San Marcos River,
    downstream approx. 50 m from Spring Lake Dam,
    Hays County, Texas (50 CFR 17.95(d)).
  • Special rules concerning "take" for this species
    can be found in 50 CFR 17.43(a).
  • This species is protected by the Lacey Act
    (P.L. 97-79, as amended; 16 U.S.C. 3371 et seq.)
    which makes it unlawful to import, export, transport,
    sell, receive, acquire, or purchase any wild animal
    (alive or dead including parts, products, eggs, or
    offspring): (1) In interstate or foreign commerce if
    taken, possessed, transported or sold in violation of
    any State law or regulation, or foreign law; or (2) If
    taken or possessed in violation of any U.S. law,treaty,
    or regulation or in violation of Indian tribal law.
  • It is also unlawful to possess any wild animal
    (alive or dead) including parts, products, eggs, and
    offspring within the U.S. territorial or special maritime
    jurisdiction (as defined in 18 U.S.C. 7) that is taken,
    possessed, transported, or sold in violation of any
    State law or regulation, foreign law, or Indian tribal law.
  • All Federal agencies have responsibility to ensure
    that any action authorized, funded, or carried out by
    that agency is not likely to jeopardize the continued
    existence of the species or result in the destruction
    or adverse modification of Critical Habitat (50 CFR 402),
    and to utilize their authorities to carry out programs
    for the conservation of the species.
  • The San Marcos salamander is listed as rare in the
    1986 IUCN Red List of Threatened Animals.
  • A series of five flood retardation structures
    initiated by the Soil Conservation Service on tributary
    creeks feeding into the San Marcos River is expected to
    decrease the severity of flooding in the watershed and
    to slightly increase the recharge into the aquifer, thus
    producing a slight overall benefit to the ecosystem.
  • The headwaters of the San marcos River at the
    northmost end of Spring Lake near the hotel tend to be
    protected from flooding action. This undoubtedly
    contributes to the continued survival of the San Marcos
    salamander population since the salamander is not a
    strong swimmer and the loss of protective vegetation and
    food supply could be critical.


Music From: I Will Survive



Last Updated: 19-March-1999
WebMaster: Daisy Moreno daisymoreno@HotMail.com
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