VN:F [1.9.22_1171]Other Vertebrates,
Amphibians are a group of cold-blooded vertebrates. They go through metamorphosis after hatching. They change from gill-breathing (completely water-depending) like fish to lung-breathing (living mainly on land). They hibernate during winter.
They are considered ecological indicators. Their presence indicates lack of pollutants in the environment.
There is only one order registered here – Anura (toads and frogs).
Main differences between frogs and toads for identification.
Frogs have smooth skin and longer hind legs adapted for leaping.
Toads are bulky and have warty skin. Their hind legs are short (for walking not for leaping)
|Hensel’s Swamp Frog
|Spotted Thin-toed Frog
|Bella Vista Toad
Mammals are a class of warm-blooded vertebrates. They possess hair and mammary glands, which produce milk to feed the young. They are viviparous, that is, the embryo develops inside the body of the mother. The degree of maturity at birth differentiates three subclasses (monotremes, placentals and marsupials). There are photographic records of 7 species of placentals and one marsupial.
Placentals are nourished in the mother’s uterus through the placenta. Young are born live and do not take long to fend for themselves. Though most placentals are difficult to see during the day, coypus and guinea pigs may be the exceptions. Unluckily coypus are visitors from time to time nowadays.
Marsupials, instead, have no true placenta, therefore the embryo has to obtain nutrients somehow. As they leave the uterus they present an uneven development. Hind legs and facial parts are more developed than other parts of the body. By using the hind legs they will crawl to the nipple where they will remain attached to until they complete development. This is the case of the Thick-tailed Opossum.
|Brazilian Guinea Pig
|Yellow Pygmy Rice Rat
|South American Fur Seal
| House mouse
Turtles belong into the order of reptiles. They are characterised by a protective shield which allows only head, legs and tail to be seen through two openings, one at the front and the other at the back. In case of threat these parts may also disappear in the inside. The shield consists of two shells -carapace and plastron, upper lower parts respectively- joined together at the sides by bony structures.
Turtles are classified according to the way they withdraw their head into their shells. Side-necked turtles or Pleurodira fold their long neck laterally between the carapace and plastron leaving the head and neck partially exposed. They are only found in the Southern Hemisphere.
Hidden-necked turtles or Cryptodira pull their heads back into the shell with vertebrae adopting an S form in the inside. Both groups are represented at Costanera.
The four registered species (three are native and one is exotic) live in the ponds. Webbed feet, limbs rather flattened and a streamlined carapace are the adaptations to aquatic life. Though they spend most of their time in water they lay eggs on land. Females dig a hole where eggs are buried and left unattended.
Trachemys scripta elegans
Trachemys scripta dorbignyi
| Scaled Reptiles
They are so called because their body is covered with horny scales. They are divided in three suborders quite different in appearance: lizards, snakes and worm lizards. All of them are represented at Costanera.
Lizards have four short legs adapted to locomotion. The long tail can be shed and regenerated. The mandibles are not mobile. On the contrary, the eyelids are.
Snakes have no limbs, so they crawl. They have elongated body and tail. Mandibles are joined by ligaments. This gives great bite mobility allowing the passage of big pieces through them. They have no mobile eyelids; only a fixed and transparent eyelid covers the eye.
Snakes may be venomous or non-venomous. Some traits may help us to tell them apart. Unfortunately they are not always foolproof. So it is wise to keep away from them in case of doubt.
a) Non-venomous snakes have big scales covering their heads. Venemous snakes have small scales.
b) Non-venomous snakes have big eyes and round pupils. Venomous snakes have smaller eyes and elliptical pupils like the cat’s eye.
c) Non-venomous snakes have rounded heads. Venomous snakes have spear-like heads.
Worm lizards are adapted to underground life. They have an elongated cylinder-like body and are limbless, but for one species. Scales arrange in rings. So, worm lizards move in an accordion-like way and can do it forwards or in reverse indistinctly. It has atrophied eyes. Tail and head are quite similar in form and almost indistinguishable.
|Black-and-white Tegu Lizard
|Red Tegu Lizard
|Sand Coastal Housesnake
|Tree Coastal Housesnake
|Urutu Pit Viper
Fish are aquatic vertebrate animals which are characterized by having most of them scales, fins and gills, which allow them to get the oxigen from water. They are ectothermic, that is cold-blooded, their temperature varies according to ambient temperature.
|Marbled swamp eel