Reptiles and Amphibians
Compiled by
Bernadette Holt
WSFC 611
Fall 97
Summary:
There are many different types of reptiles and
amphibians that inhabit the coastal regions of the United States.
A great number of these can be found in the Texas coastal area
and are a vital part of the estuarine systems. Reptiles include
alligators, turtles, snakes, and lizards. The amphibian category
encompasses frogs, toads, and salamanders.
REPTILES
Alligators:
The alligator that is most prevalent along the Texas coast is
the American Alligator (Alligator Mississippiensis). The average
body length is anywhere from 6-l6 feet. Alligators are
semi-aquatic creatures that are almost black in color, They have
distinctive eyes and nostrils and rather large, coarse scales.
The front feet consist of five toes, whereas the hind feet have
four toes that are webbed. Alligators are carnivorous and will
eat almost anything that it can catch, which includes fish,
lizards, turtles, snakes, crustaceans, mammals and waterfowl.
Alligators begin their breeding cycle upon emerging from
hibernation which normally occurs in April. The average clutch is
over 50 eggs and the female will cover them with leaves and
vegetation in order to incubate them. Hatching in about nine
weeks, the young will "peep" to signal their arrival
and the female will then dig them out of the nest. At birth, an
alligator will measure approximately 9 inches long and will
remain near the mother for up to a year for protection.
While normally found in fresh water, alligators can abide in
brackish waters as well. Once identified as endangered species,
the alligator now enjoys protection as a game animal in Texas.
Web Links:
http://tpwd.state.tx.us/nature/wild/reptiles/reptiles.htm
http://www.sazoo-aq.org/alligatr.htm
Turtles:
There are five species of sea turtles that are know to
inhabit the Texas gulf coast region. All of these species, with
the exception of the Kemp's ridley, can be found throughout the
world. The Kemp's ridley, however, is found only in the Gulf of
Mexico and northern Atlantic.
The Kemp's ridley sea turtle (Lepidochelys kempii) is the
smallest species of sea turtle. At maturitv the carapace averages
56 to 76 cm in length and usually weighs less than 45 kg.
The circular carapace is distinctive because of the light olive
green color with a yellow plastron.
While the Kemp's ridley use to be abundant, the number of nesting
females has drastically decreased. In 1947 there were an
estimated 40,000 nesting females. In 1985 the estimate had
dropped to 500 females. Since being put on the endangered species
list in 1970, the number of nesting females has risen to
approximately 1000. Kemp's ridley are most commonly found in mass
nesting situations referred to as "arribadas." It is
speculated that the reason for such behavior may be a survival
tactic to overwhelm predators such as coyotes, and thereby
allowing the survival of the nesting females and their nests
along with a number the hatchlings.
The primary diet of the Kemp's ridley is crabs. They may also eat
shrimp, snails, clams jellyfish, sea stars, and small fish. Their
affinitv for crabs has made them the enemy of fisherman who set
out crab pots.
Because of a greater number of trawlers in the Gulf of Mexico,
Kemp's ridley captures are 4-5 times greater here than in the
southeast Atlantic. The average estimate of captures is
approximately 1,725 annually. Because the length of trawling
times in the western Gulf are longer than in the central Gulf,
deaths of ridley's are thought to be double off the shores of
Texas, resulting in an estimated 250 deaths per year.
Web Site:
http://tpwd.state.tx.us/nature/endang/kempsrid.htm
The Loggerhead (Caretta caretta) which receives its common
name from the relatively large size of its head, is among some of
the other sea turtles that can be found along the Texas coast.
The most common species of sea turtle is reddish-brown in color
with yellowish underside that may contain tinges of it’s
dorsal coloration. It averages 90 cm in carapace length at
maturity and 135kg in weight.
Another of the common sea turtles is the Green Turtle (Chelonia
mydas). At maturity it can be classified as a medium to large
turtle. The carapace can attain a length of approximately one
meter and weighs 136 kg or more. It can be identified by its
relatively small head and oval carapace. The color can vary from
medium to dark brown and is mottled with light tan. Its common
name is derived from the color of the fat beneath its shell. It
has been referred to in the past as "the edible Turtle"
or "the soup turtle", which leads one to speculate as
to the major cause of its decline. Once abundant in the
Caribbean, it has also been known as the Texas turtle because of
the commercial fishery trade in the Corpus Christi area up until
the 1890's.
The Hawkbill turtle (Eretmochelys imbricata) is an uncommon
turtle in the northern Gulf of Mexico. It is considered the most
tropical of all sea turtle species. It has slender jaws that are
designed to extract prey from crevices along coral reefs and
rocky bottoms. Even though it often appears to be an
opportunistic feeder, it is believed that sponges maybe its
favorite food. At maturity the average adult's carapace measures
about 100 cm in length and is can weigh from 45 to 90 kg. The
specific name imbricata refers to the overlapping of the scutes
of its carapace. It is for the unusually unique design of the
carapace that this species has been over exploited and turned
into combs and other trinkets.
The last of the most commonly known sea turtles of the Texas
coast is the Leatherback turtle (Dermochelys coriacea). Its name
comes from its leathery skin. The specific name coriacea comes
the Latin word corium which means leather; while the genius
incorporates the Greek derma of the same meaning. It is the
largest of the sea turtles with a carapace length of 190cm, and a
weight of 600 kg. The large ridges units back are thought to be
hydrodynamic adaptation. Adults are normally black with white
flecks, while the underside is white with black flecks. The front
flippers are rather large when compared to other species. While
not hunted commercially for its meat, the fat under its carapace
has been rendered into oil used for calking boats, and medicinal
applications.
Snakes:
Snakes are a vital link in the food chain of most ecosystems.
they are helpful in keeping populations of smaller animals in
check and calling out injured or dying prey. The also provides food source for birds of prey such as herons and
egrets.
Salt marsh snakes are hard to find and occur mainly in areas
where strong waves current and tides are not prevalent. While
often confused with the cottonmouth because they are found near
water salt marsh snakes are nonpoisonous. They are generally
smaller and their color somewhat different from their fresh water
relatives - ranging from brown to gray to olive green with
stripes.
The most common species of Salt Marsh Snake in Texas is Nerodia
clarkii. The average adult ranges in size from 15 -30 inches
in length. its dorsal pattern consists of two longitudinal tan or
yellow stripes on each side of the body. The ventral surface is
brown or rust colored with a single row of large pale spots along
the center. It is found along the coast of the Louisiana border
to near Corpus Christi.
Other snakes are also found in the coastal regions of Texas but
not as frequently in marsh areas. These include the Cotton Mouth
(Agkistrodon picivorus) and the Gulf Crayfish Snake (Regina
rigida sinicola).
Lizards:
Several lizards make their homes along the coastal regions of
the Texas coast. One of these is the Keeled Earless Lizard
(Holbrookia propinqua). The adult is 4 1/2 - 5 1/2 inches in
length with a dorsal ground color of green-gray or brown. It is a
small lizard with small keeled scales and no external ear
openings. This lizard prefers to live in sandy environments and
is common on sand dunes and barrier beaches within its range. It
is a diurnal creature and forages for insects among the sand
dunes. It retreats quickly when threatened and is normally found
in South Texas and along Mexico’s Gulf Coast.
Several of the other lizards that inhabit the coastal regions of
Texas are the Western Slender Glass (Ophisaurus attenuarus) and
the Mediterranean Gecko (Hemidactylus turcicus). Also found in
this area are several skinks. These may include the Five-lined
Skink (Eumeces faciatus), the Broadhead Skink (Emeces laticeps),
and the Ground Skink (Scinella lateralis).
AMPHIBIANS
Frogs and Toads:
Frogs and toads are among amphibians that inhabit regions of the Texas Gulf Coast. One of the most common toads found in this are is the Gulf Coast toad (Bufo valliceps). The normal size at maturity is 2-4 inches in length. It can vary in color from almost black to brownish yellow. It also has a broad dark stripe down each side of the dorsum, light stripes above. It is a rather flat toad with well defined cranial crests. The habitat of this toad can vary greatly from coastal prairies and barrier beaches along the Gulf of Mexico to roadside and irrigation ditches to urban/suburban sewers and backyard gardens. It feeds on insects and is most active at twilight.
Resources for Reptiles and Amphibians:
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