January 7, Image by Flickr user takfoto, under Creative Commons License This paper considers different methods to measure stress in reptiles, as well as the environmental factors that might lead to stress responses in the first place. There are many factors that could contribute to the stress of different species of reptiles, but this paper highlights capture and living in captivity as stressful situations that cause corticosteroid release in many reptile species. The author uses previously published literature to demonstrate how different levels of stress may result in different physiological responses in reptiles, and describes non-invasive, non-captive ways of measuring stress in reptile populations. Conversely, acutely or intensely stressed reptile species are predisposed to emaciation, immune depression, and reproductive difficulty.
Crocodyla crocodiles, alligators, gharialsTestudines turtles and tortoisesSquamata lizards and snakesand Rhynchocephalia tuataras. Reptiles are vertebrates with organ systems similar to those of mammals. However, they are ectothermic and rely on environmental temperature and behavior to control their core body temperature.
They possess both renal and hepatic portal circulations, and predominantly excrete ammonia, urea, or uric acid depending on their evolutionary adaptations. Their RBCs are nucleated, and their metabolic rates are lower than those of mammals.
All reptiles exhibit ecdysis—a normal process by which the outer skin is periodically shed. Diurnal species require broad-spectrum light for vitamin D3 synthesis and calcium homeostasis.
Fertilization is internal, and females may produce eggs oviparous or live young ovoviviparous. Reptiles are not considered highly social creatures, and multiple-male groups can lead to intraspecies aggression. Single-male, multiple-female groupings can work well for certain species, but the solitary reptile is often the healthiest pet.
The life span of many reptiles can exceed 10—20 yr, requiring a longterm commitment from owners. Reptiles possess a common cloaca, which receives the lower GI, reproductive, and urinary tracts.
Two major groups of the world's animals are mammals and reptiles. Both are vertebrates because they have a backbone. Both are found just about everywhere in the world (reptiles are not found in the polar regions). Vertebrate animals, including fish, amphibians, reptiles, birds and mammals, represent the a puny 3% of all living species. The list below provides estimates of the number of species within the various animals groups. Species identification is essential to critically appraise captive diets (see Table: Composition of Animal Foods that May Be Offered to Reptiles and see Table: Composition of Plant Foods that May Be Offered to Reptiles). Rodent-eating carnivores such as most snakes present few problems as long as the rodent is recognizable to .
In addition, lungs are simpler and composed of vascular pockets, more like a cavitated sponge than alveoli. Lizards and chelonians are quadrupeds and have a familiar pentadactyl limb arrangement. Reptiles lack a true diaphragm; in many species, all organs are contained within a single coelomic cavity.
Boas and pythons are primitive snakes and have both left and right lungs; however, other snakes lack a developed left lung. Squamates have incomplete tracheal rings, and males have paired copulatory organs hemipenes. The chelonians are characterized by their shell, which comprises a dorsal carapace and ventral plastron.
The internal organs are separated by two thin membranes. The heart is located within a cardiac membrane, while the lungs are dorsad and separated from the remaining viscera by a postpulmonary membrane or septum horizontale.
Chelonians have complete tracheal rings, and males have a single copulatory phallus. Reptiles rely on environmental temperature and behavior to maintain their body temperature within their preferred optimal temperature zone POTZ.
Within this species-specific POTZ, a reptile is able to achieve the preferred body temperature for specific metabolic activities, which may vary diurnally and seasonally and by age and gender. The metabolic rate of reptiles is lower than that of mammals and birds. All snakes, lizards, and chelonians have a three-chambered heart two atria and one ventriclewhereas crocodilians have a four-chambered heart.
All reptiles have both pulmonary and systemic circulations similar to mammals. In noncrocodilian reptiles, functional separation of venous and arterial blood is largely maintained via a muscular ridge within the ventricle.
Peripheral blood cell types include erythrocytes, heterophils, eosinophils, basophils, lymphocytes, monocytes including azurophilsand thrombocytes. Renal and hepatic portal circulations exist, and intra- and extracardiac vascular shunts may be present, especially in aquatic species.
Reptilian skin is usually heavily keratinized and protected by scales. The chelonian shell is composed of both dermal bone plates and keratinized epithelial scutes. Reptiles do not have extensive skin glands, and their skin is essentially dry.
However, many male lizards have a series of pre-anal or femoral pores located cranial to the vent or along the craniomedial aspect of the hindlimbs.
In some species, both sexes have these glands, but they are more pronounced in the male.Snakes in the garden: an analysis of reptiles ‘‘rescued’’ by community-based wildlife carers Richard Shine*, Jennifer Koenig Biological Sciences A08, University of Sydney, NSW Australia.
Reptiles are priority species in England, Wales, Scotland and Northern Ireland. In England, Scotland and Wales, grass snake, common lizard, slow worm and adder are all protected by the Wildlife and Countryside Act (as amended) from intentional killing, injury and selling.
While the techniques described serve as a guide to necropsy reptiles, we focus on exotic species found in south Florida. Avoid freezing the animal before blood or tissue analysis, however, because it compromises samples (Stahl ). Veterinarians must not only be familiar with common reptile species and their management but also be able to extract clinically relevant husbandry information from the owner in a timely manner.
The use of a history form can greatly facilitate this process and ensure that nothing is overlooked. Species of reptiles, amphibians and other vertebrates are becoming extinct in Haiti as deforestation has claimed more than 99 percent of the country's original wooded areas.
Species of reptiles. This paper considers different methods to measure stress in reptiles, as well as the environmental factors that might lead to stress responses in the first place. There are many factors that could contribute to the stress of different species of reptiles, but this paper highlights capture and living in captivity as stressful situations that cause .