More about Amphibians & Reptiles:
I frequently encounter iguana owners who tell me that their iguanas defecate only once or twice a week even though they are eating daily. This tells me right away that their temperatures are too low. Once they are raised to the proper levels, the owners are often dismayed to find that, not only does the iguana increase its food intake, but its digestion speeds up to the proper rate, resulting in often copious defecation one or more times a day, depending upon the season.
Most of these owners also find that their iguana isn't really as tame as they thought it was. Common Feeding Problems Failure of a reptile to feed may be due to one or more of several possible reasons. To get the reptile to start eating, the underlying cause for the failure to feed must be identified and corrected: Simply forcing feeding an animal will not correct the problem situation; it will just give the animal energy to survive, not thrive.
Reasons for not eating include: If possible, it is always best to get the reptile to start self-feeding rather than resort to long-term forcing feeding or tube feeding. Once you have assured that the reptile is healthy and in a properly established environment, certain tricks may be employed if the reptile is still not self-feeding: Changes in Temperatures and Humidity The humidity and temperatures in an enclosure will vary through the year as the ambient room air temperatures and humidity rise and fall.
You may need to boost the humidity artificially more during the winter and winter months than during the Fall, for example. Hygrometers can be used to measure humidity and may be used as a guide to alert you when you need to boost the humidity or back off.
Unfortunately, more is known about the temperature requirements of species kept in captivity than is known about their humidity needs. In the absence of specific humidity data, you will have to learn how to judge the adequacy of humidity based on the above points.
During the the winter, the fall in outside temperatures results in a lowering of the temperatures inside our homes. This drop in ambient room air temperature often results in a lowering of the temperatures inside the reptile enclosures.
Always monitor the temperatures with several thermometers placed inside the enclosure. You may find that during the colder months you many not only have to boost humidity inside the room or enclosure, but you may have to add stronger or additional heating equipment just to be able to maintain the proper temperatures.
One final factor that must be mentioned is the human tendency to demand that animals share the human's time schedule. Many people work during the day, coming home tired at night, often with an hour or more of chores to be done before they can settle down to relax. At that time, they may want to feed their reptile, or take it out for some together time. The problem is that if their reptile is a diurnal active during the day species, it needs to sleep at night.
Constant disruption of the sleep cycle, as well as being forced to eat at night rather than during the day, results in long term low levels of stress. The same is true for people who work or otherwise stay up all night and sleep throughout most of the day.
While this life style may be okay for nocturnal reptiles other than the fact that nocturnal species do still require darkness at night to function normally , it is stressful for the diurnal and even for many crepuscular species.
When we keep animals, we must accommodate their needs; they should not be forced to accommodate our schedules. So, what does all of this have to do with my reptile's health? Stresses, little and big, as well as the direct effects of environmental problems cage size, orientation, heating, lighting, feeding, humidity, etc.
Stress itself can suppress immune function, making the body unable to naturally fight off infection or keep internal parasites under control. The more stress, or the longer that it is allowed to continue, the weaker the animal becomes and the less tolerant it is to continued stresses and other problems in its environment.
Reptiles take a long time to die. Because of their ectothermy, their cold-bloodedness, they are able to conserve energy to maintain basic body functions for a long time, long after a mammal or bird would have succumbed or have deteriorated to the point where the owner would notice.
Reptiles do not die "suddenly. Those animals most adept at suppressing signs of ill-health or injury are those that will have a chance to recover before being eaten. In the wild as in captivity, reduced activity and increased hiding are behaviors associated with attempts at conserving energy the less one moves, the fewer calories burned, a common reaction to slow starvation and to giving the body more calories to put into healing, for example and trying to hide to avoid predation when the animal is too weak or too cold to effectively defend itself.
Behavioral Changes Changes in behavior can be a sign of an underlying physical problem. We tend to think of health problems as causing lethargy and loss of appetite, but animals may also become snappy, cranky, and may react abnormally to accustomed interaction and stimuli.
Some iguanas may get aggressive. When the aggression occurs in green iguanas, known for their breeding season and territorial aggression, such behavioral changes are often dismissed as "just" being related to "typical" male aggression. As an increasing number of iguana keepers are finding, abnormal aggression may also caused by huge bladder stones, tumors, abscessed organs, and other as yet undefined, pain, disorders and pathologies.
When investigating the possible causes of abnormally aggressive behavior, do not discount a primary physiological cause until you and your vet have thoroughly checked it out. Behavioral assessment of welfare. Scientists Center for Animal Welfare. The science of animal well-being. Animal Welfare Information Center Newsletter, 4 1 , The psychological well-being of reptiles.
Humane Innovations and Alternatives , Evaluating pain and stress in reptiles. The use of behavioral management techniques to reduce or eliminate abnormal behavior.
Animal Welfare Information Center Newsletter, 4 , , Saunders Company, Philadelphia, PA. Biological response to stress: Key to assessment of animal well-being? Society for the Study of Reptiles and Amphibians. Captive management and conservation of amphibians and reptiles. Murphy, Kraig Adler, Joseph T.
Reptilian ethology in captivity: Observations of some problems and an evaluation of their aetiology. Appl Anim Behav Sci, 26 , Important ethological and other considerations of the study and maintenance of reptiles in captivity.
Applied Animal Behaviour Science, 27 4 , Observations on disease-associated preferred body temperatures in reptiles. Applied animal behavior science, 28 4 , Health and welfare of captive reptiles. An introductory biology of amphibians and reptiles.
Academic Press, New York. Fluid and Fluid Therapy for Reptiles. Guidelines for Medicating Sick Herps. Iguana Breeding Season Basics. Signs of Ingestion of Toxic Substances. Heading off problems before they start. Can't find a vet on my site? Check out these other sites. Are there any lateral folds, or are the folds normal for the species exaggerated in appearance or are there more of them?
Has there been a change in color? Is the color of the skin dulling, darkening? Has food intake dropped off? Are they selecting foods with higher moisture content? Is there less urates? Is it thicker, more viscous? Are fecal masses smaller, harder, drier? Is the reptile lethargic? Spending more time in hiding or in the cooler end of the thermal gradient? Spends more time in basking area?
Prolonged soaking in water bowl? More active, especially at odd times? Engaging in frequent or prolonged digging, scratching or head-banging behavior? Increased or decreased tongue-flicking when handled or enclosure is opened? Has the usually tame reptile become aggressive not associated with breeding season? Has the shed schedule become erratic? If the reptile should be shedding in one piece all snakes, some lizards , is it?
Are sheds taking much longer than usual to complete? Is it gaping sitting with open mouth for long periods of time? Increased or thickened saliva? The Reptilia class is further divided into several extant sub-groups:. The useful defenses of these animals help them to survive in their wild habitat.
The defense mechanism can vary from one sub-group to another. Birds and larger Reptiles are among the main predators of many smaller lizards and snakes. The brown, green and mottled green colorations of the small animals help them to remain camouflaged in their natural habitat and avoid detection of their predators, who have well-developed color vision. Various lizards like skinks and geckos can shed their tail when captured by it.
This process, called autotomy, enables these animals to run away by distracting their enemies. The detached tail continue to wiggle which makes the predator think that the lizard is still struggling, keeping their attention from the escaping prey. The shed tail can be regenerated within a few weeks, but it is smaller than the original one and looks quite different from the rest of the body.
The principal defense mechanism in various snake species is their ability to deliver poison through their fangs. Poison glands located inside their mouth produce deadly venom that helps the creatures to protect themselves from enemies.
These animals originated around million to million years ago with the first reptiles evolving from the advanced reptiliomorph labyrinthodonts. Animals from the Casineria genus are the earliest animals suspected to be amniotes rather than advanced amphibians.
The origin of reptiles occurred in steaming swamplands of late Carboniferous period. Fossils found in Nova Scotia show footprints with imprints of scales and typical reptilian toes. The prints have been attributed to Hylonomus which is the earliest recognized reptile. Hylonomus was a lizard-like creature 8 to 12 in long with sharp teeth that indicates an insectivorous diet. Earlier, the bigger labyrinthodont amphibians like Cochleosaurus largely overshadowed the reptiles, who remained inconspicuous until the CRC or Carboniferous Rainforest Collapses.
This significant extinction event affected the existence of many large animals with the Amphibians being among the worst affected populations. But, the reptiles coped better with the drier conditions post CRC. One of the biggest problems the Amphibians faced was the lack of water bodies which prevented them from reproducing. This did not affect reptiles as they were able to lay eggs on dry lands. Gradually, the reptiles became a dominating class with new diet strategies including both carnivory and herbivory.
This established the foundation for the Mesozoic stage, also referred to as the Age of Reptiles. The genus Mesosaurus from the Permian period is counted among the most recognized early reptiles. Most Reptiles are unable to see properly during nighttime as their vision is mainly adapted to the daylight conditions. They have color vision with the visual depth perception being much more advanced than Amphibians and many Mammals.
The vision is reduced in species like the Blind Snake, while some snakes have extra visual or sensory organs that make them sensitive to heat and infrared radiation.
The horny epidermis layer makes their skin watertight, allowing these animals to inhabit dry land. Reptiles have thinner skin compared to mammals and it also lacks the dermal layer present in mammal skin. The exposed skin areas are covered in scutes or scales which may have a bony base, creating their armors. In turtles, a hard shell made up of fused scutes covers the entire body. Reptiles use their lungs for breathing. The skin of the aquatic turtles is more permeable for allowing them to respire while the cloaca is modified in various species to increase the gas exchange area.
Despite these adaptations, lungs remain a very important part of their respiratory system. The main Reptile groups accomplish lung ventilation in different procedures. Squamates are known to ventilate the lugs mainly by their axial musculature. Certain lizard species are capable of buccal pumping apart from the normal axial breathing.
The proto-diaphragm in Tegu lizards separates their pulmonary cavity from visceral cavity, helping with their respiration by allowing greater lung inflation. The muscular structure of the diaphragm in the Crocodilians species resembles that of various mammals. However, there are some differences in their diaphragmatic setup. They also have two aortas playing a major role in their systemic circulation.
The oxygenated and deoxygenated blood may get mixed with each other in their three-chambered heart with the level of mixing depending on the species and the physiological state of the animal. Their circulatory system is capable of shunting back the deoxygenated blood to the body and the oxygenated blood to the lungs if necessary. Unlike other Reptiles, animals in the crocodilian subgroup have four-chambered hearts.
But, their two systemic aortas are only capable of bypassing their pulmonary circulation. On the other hand, the three-chambered hearts in various lizard and snake species can function as the four-chambered ones during contraction.
Majority of these animals have short digestive tracts because their diet mainly consists of meat, which is very simple to digest. Their digestion process is slower than that in mammals due to their inability of mastication and their low metabolism rate while resting. The energy requirements for their poikilotherm metabolism are very low which allows large animals from this class such as various constrictors and crocodiles to survive for months from one large meal, digesting it slowly.
Herbivorous reptiles are also unable to masticate their food, which slows down the digestive process. Some species are known to swallow pebbles and rocks that help in grinding up plant matters within the stomach, assisting their digestion. The basic nervous system in the Reptiles is similar to that in the Amphibians. But, Reptiles have slightly larger cerebrum and cerebellum. Most of the important sensory organs are properly developed in these creatures.
However, there are certain exceptions such as the absence of external ears in snakes they have the inner and middle ears. Reptiles have twelve cranial nerve pairs. They have to use electrical tuning for expanding the range of their audible frequencies because they have short cochlea. These animals are believed to be less intelligent compared to mammals and birds because the relative size of their brain and body is much smaller than that of the latter.
However, the brain development can be more complex in some larger Reptiles. Modern species also have pineal glands in their brains. Most of these animals are tetrapods, meaning they have four legs. Snakes are examples of legless Reptiles. Their skeletal system is similar to other tetrapods with a spinal column supporting their bodies.
Their excretory system consists of two small kidneys. The diapsid species excrete uric acid as the principal nitrogenous waste product. But, turtles excrete mainly urea. Some of these species use their colons for reabsorbing water, while some are able to absorb the water stored in their bladders.
Certain Reptiles excrete the excess salts in their bodies through the lingual and nasal salt glands. Reptiles have certain characteristic features that help in distinguishing them from Amphibians, Mammals and Aves:. They are capable of adapting to almost all kinds of habitats and environmental conditions, except for extremely cold regions.
These animals can inhabit dry deserts, forests, grasslands, wet meadows, shrub lands and even marine habitats. Reptiles are capable of adapting to extremely high temperatures because they are cold blooded. Various snakes including the Rattle Snakes and King Snakes as well as different lizards like the Gila Monsters live in desert habitats.
Grassland is another common type of habitat for various snakes and lizards e. Garter Snakes, Fox Snakes. The vegetation in this habitat attracts many insects and rodents, making it easier for the Reptiles to catch prey.
Swamps and large water bodies are inhabited by different Reptiles such as crocodiles, alligators, certain turtles and snakes. Animals like the Saltwater Crocodile and Marine Iguana inhabit seaside, travelling in and out of ocean as necessary. Some species, such as the Sea Snakes and Sea Turtles, live in the ocean.
They leave the waters only during the breeding season for laying eggs. These animals typically practice sexual reproduction with some specific species using asexual reproduction. Majority of these animals are amniotes, laying eggs covered with calcareous or leathery shells. The eggs are generally laid in underground burrows dug by the females. The viviparity and ovoviviparity modes of reproduction are used by many species such as all boas and many vipers.
However, the level of viviparity may vary with some species retaining their eggs until shortly before hatching while others nourish the eggs for supplementing the yolks. In some Reptile species, the eggs do not have any yolk with the adults providing all the necessary nourishment through a structure resembling the mammalian placenta.
Six lizard families and one snake family from the Squamata sub-group are known to be capable of agamogenesis or asexual reproduction. In some squamate species, the females are capable of giving birth to unisexual diploid clones of themselves. This type of asexual reproduction is known as parthenogenesis, occurring in various teiid lizards, geckos and lacertid lizards.
Komodo dragons have reproduced through parthenogeny in captivitiy. Like many mammals, birds and Amphibians, their embryonic life consists of an amnion, chorion, as well as an allantois.
The incubation period may vary depending on the species and other factors like the temperature of the surroundings. Usually, hatchlings are able to take care of themselves almost immediately after coming out of the eggs.