Dahl's Toad-headed Turtle
Encyclopedia
The Dahl's toad-headed turtle (Mesoclemmys dahli) is a species of turtle
in the Chelidae
family.
It is endemic to Colombia
.
is oval to elliptical (to 21.5 cm) and widest behind the middle with a slightly serrated posterior rim. It is somewhat flattened dorsally, and the lateral marginals are upturned. A poorly developed vertebral keel may be present in juveniles and some adults. The flared 1st vertebral is the largest and broader than long, as is also the flared 5th. The 2nd and 3rd vertebrals are also usually broader than long, but the 4th, the smallest of the series, may be slightly longer or as long as broad. The cervical scute is normally longer than broad. The well-developed plastron is notched posteriorly. Its forelobe is longer and broader than the hindlobe; the narrowness of the posterior lobe is particularly noticeable in males, and its breadth is only 36-38% of the plastral length. The bridge is relatively broad. We have seen few specimens of Phrynops dahli, but in those measured the plastral formula was: intergul > fem > abd > pect > an > hum >< gul. The intergular completely separates the gulars. Plastron, bridge, and undersides of the marginals are cream to yellow with gray pigment outlining the seams. The head is large and broad with a slightly projecting snout and slightly notched upper jaw. There are twochin barbels, and the dorsal surface of the head is covered with small to large, irregularly shaped scales. Dorsally, the head is gray to olive brown, but the upper jaw, tympanum, and sides are cream to yellow. Lower jaw, chin, and barbels are yellow. The neck is gray dorsally but lighter ventrally. No horny tubercles are present on the neck. Limbs and tail are gray to olive brown on the outside but lighter beneath.
The karyotype
is 2n = 58: 22 macrochromosomes, 36 microchromosomes (Bull and Legler, 1980). It differs from that of M. nasutus in having the 8th chromosome pair biarmed.
Males have longer, thicker tails, narrower posterior plastral lobes, and narrower heads. The head of the female is swollen behind the eyes.
, northeastern Colombia
.
Phrynops dahli is predominantly carnivorous, feeding on snails, aquatic insects, other aquatic invertebrates, fish, and amphibians; carrion
is also eaten.
Turtle
Turtles are reptiles of the order Testudines , characterised by a special bony or cartilaginous shell developed from their ribs that acts as a shield...
in the Chelidae
Chelidae
The Chelidae are one of the three living families of the turtle suborder Pleurodira and are commonly called the Austro-South American Side Neck turtles. The Family is distributed in Australia, New Guinea, parts of Indonesia and throughout most of South America. It is a large family of turtles with...
family.
It is endemic to Colombia
Colombia
Colombia, officially the Republic of Colombia , is a unitary constitutional republic comprising thirty-two departments. The country is located in northwestern South America, bordered to the east by Venezuela and Brazil; to the south by Ecuador and Peru; to the north by the Caribbean Sea; to the...
.
Recognition
The olive to brown carapaceCarapace
A carapace is a dorsal section of the exoskeleton or shell in a number of animal groups, including arthropods such as crustaceans and arachnids, as well as vertebrates such as turtles and tortoises. In turtles and tortoises, the underside is called the plastron.-Crustaceans:In crustaceans, the...
is oval to elliptical (to 21.5 cm) and widest behind the middle with a slightly serrated posterior rim. It is somewhat flattened dorsally, and the lateral marginals are upturned. A poorly developed vertebral keel may be present in juveniles and some adults. The flared 1st vertebral is the largest and broader than long, as is also the flared 5th. The 2nd and 3rd vertebrals are also usually broader than long, but the 4th, the smallest of the series, may be slightly longer or as long as broad. The cervical scute is normally longer than broad. The well-developed plastron is notched posteriorly. Its forelobe is longer and broader than the hindlobe; the narrowness of the posterior lobe is particularly noticeable in males, and its breadth is only 36-38% of the plastral length. The bridge is relatively broad. We have seen few specimens of Phrynops dahli, but in those measured the plastral formula was: intergul > fem > abd > pect > an > hum >< gul. The intergular completely separates the gulars. Plastron, bridge, and undersides of the marginals are cream to yellow with gray pigment outlining the seams. The head is large and broad with a slightly projecting snout and slightly notched upper jaw. There are twochin barbels, and the dorsal surface of the head is covered with small to large, irregularly shaped scales. Dorsally, the head is gray to olive brown, but the upper jaw, tympanum, and sides are cream to yellow. Lower jaw, chin, and barbels are yellow. The neck is gray dorsally but lighter ventrally. No horny tubercles are present on the neck. Limbs and tail are gray to olive brown on the outside but lighter beneath.
The karyotype
Karyotype
A karyotype is the number and appearance of chromosomes in the nucleus of an eukaryotic cell. The term is also used for the complete set of chromosomes in a species, or an individual organism.p28...
is 2n = 58: 22 macrochromosomes, 36 microchromosomes (Bull and Legler, 1980). It differs from that of M. nasutus in having the 8th chromosome pair biarmed.
Males have longer, thicker tails, narrower posterior plastral lobes, and narrower heads. The head of the female is swollen behind the eyes.
Distribution
This turtle is only known from Bolivar StateBolívar State (Colombia)
Bolívar State was one of the states of Colombia. Today the area of the former state makes up most of modern day Bolívar Department, Sucre Department, Córdoba Department and Atlántico Department in northern Colombia.- Limits :In 1863 it bordered:...
, northeastern Colombia
Colombia
Colombia, officially the Republic of Colombia , is a unitary constitutional republic comprising thirty-two departments. The country is located in northwestern South America, bordered to the east by Venezuela and Brazil; to the south by Ecuador and Peru; to the north by the Caribbean Sea; to the...
.
Habitat
Medem (1966) reported the habitat was originally ponds and small brooks within forests, but with the clearing of the woodlands the entire area around the type locality has been transformed into pastures. There, turtles seem to prefer shallow, quiet water bodies, where they fill a bottom-dwelling niche. Aestivation occurs during dry periods.Natural history
Medem (1966) reported the mating season in Colombia as June and July with nesting occurring mainly in September and October, but it may extend through the year. Apparently several clutches of one to six eggs are laid by each female. The white eggs are ellipsoidal (29-35 x 23–28 mm) with brittle shells, and hatchlings have carapaces about 28–30 mm long.Phrynops dahli is predominantly carnivorous, feeding on snails, aquatic insects, other aquatic invertebrates, fish, and amphibians; carrion
Carrion
Carrion refers to the carcass of a dead animal. Carrion is an important food source for large carnivores and omnivores in most ecosystems. Examples of carrion-eaters include vultures, hawks, eagles, hyenas, Virginia Opossum, Tasmanian Devils, coyotes, Komodo dragons, and burying beetles...
is also eaten.
External links
- Tortoise & Freshwater Turtle Specialist Group 1996. Phrynops dahli.