Recommendations for the Care of Amphibians and Reptiles in Academic Institutions
Total Page：16
File Type：pdf, Size：1020Kb
Recommendations for the Care of Amphibians and Reptiles Downloaded from https://academic.oup.com/ilarjournal/article-abstract/33/4/S1/744425 by Serials Biomed Library 0699 user on 03 January 2019 in Academic Institutions F. Harvey Pough NATIONAL ACADEMY PRESS Washington, D.C. 1991 Volume 33, Number 4 Fall 1991 S1 Downloaded from https://academic.oup.com/ilarjournal/article-abstract/33/4/S1/744425 by Serials Biomed Library 0699 user on 03 January 2019 On the cover: The green tree python (Chondropython viridis). (Photo courtesy of F. Harvey Pough). S2 ILAR News CONTENTS Downloaded from https://academic.oup.com/ilarjournal/article-abstract/33/4/S1/744425 by Serials Biomed Library 0699 user on 03 January 2019 Introduction S5 Amphibians and reptiles in research and teaching S5 The biology of amphibians and reptiles S6 Distinctive characteristics S6 Sources of information S7 General recommendations for the care of ectothermal vertebrates S8 The physical environment S8 The biological environment Sll Marking individuals S15 Breeding S15 Environmental conditions and medical care S16 Health precautions for release of animals S17 Health precautions for animal caretakers S17 Summary S18 Acknowledgements S18 References S18 Volume 33, Number 4 Fall 1991 S3 Downloaded from https://academic.oup.com/ilarjournal/article-abstract/33/4/S1/744425 by Serials Biomed Library 0699 user on 03 January 2019 Recommendations for the Care of Amphibians and Reptiles in Academic Institutions F. Harvey Pough, Ph.D. Downloaded from https://academic.oup.com/ilarjournal/article-abstract/33/4/S1/744425 by Serials Biomed Library 0699 user on 03 January 2019 INTRODUCTION being studied. Studies of amphibians and reptiles often have different perspectives and goals than those using Amphibians and reptiles differ in many respects from traditional biomedical species. These differences are the mammals and birds most commonly used in biomedi- reflected in the housing and care that is appropriate for cal research. These differences affect the physical and the animals. In addition, the physical and biological biological requirements of amphibians and reptiles in needs of amphibians and reptiles differ from those of captivity. In this contribution, some basic biological char- mammals and birds, and are often more difficult to pro- acteristics of these animals are described that are rele- vide in an artificial setting. Both of these factors must be vant to their husbandry. My goal is to help members of appreciated by investigators working with these animals, institutional animal care and use committees appreciate and by the individuals responsible for evaluating proto- the requirements of amphibians and reptiles in captivity, cols and husbandry practices. and to make suggestions that will be helpful in designing housing and providing day-to-day care. I will focus on amphibians and reptiles used for re- The Context of Study search and teaching in colleges and universities. In the sense that amphibians and reptiles are exotic animals in Many studies of amphibians and reptiles have an organismal a biomedical context, there are parallels between their perspective. That is, the focus of study is the intact use in academic settings and in zoos and aquariums. animal and the context is the species as it functions in its However, the facilities and resources available at col- natural environment. This approach differs from the leges and universities are more limited than those of traditional biomedical use of mammals and birds to illus- most zoos and aquariums. These recommendations ad- trate general biological phenomena or to serve as models dress the limitations and opportunities of small-scale of specific human diseases or genetic defects. In organismal husbandry. research, behavior, ecology, physiology, and morphol- The husbandry practices suggested here are compat- ogy are studied in the context of phylogenetic relation- ible with the Health Extension Act (PL-99-158), with the ships and environmental specializations. Husbandry must National Research Council's Guide for the Care and Use consider the entire biology of an organism so that normal of Laboratory Animals (NRC, 1985) with the Canadian behavior, physiological response, and morphogenesis can Council on Animal Care's Guide to the Care and Use of be assured. Much research in organismal biology is cur- Experimental Animals (Canadian Council on Animal Care, rently directed to comparative studies that investigate the 1980) and with the Guidelines for Use of Live Amphib- evolution of physiological, morphological, and behav- ians and Reptiles in Field Research (American Society ioral characteristics by studying a series of species (see of Ichthyologists and Herpetologists et al., 1987). Brooks and McLennan, 1991; Harvey and Pagel, 1991; and Huey, 1987 for examples of this approach). Studies of this sort rely upon measuring the same phenomenon (e.g., thermoregulation, parental care, or feeding me- AMPHIBIANS AND REPTILES IN chanics) in several species. Reviewers of protocols must RESEARCH AND TEACHING understand that the study of multiple species of known phylogenetic relationship is an essential element of the comparative approach, and is not unnecessary duplica- Understanding the husbandry requirements of amphib- tion. ians and reptiles begins with understanding why these animals, rather than traditional biomedical species, are Practical Considerations Dr. Pough is professor of Ecology and Systematics and director Providing environments suitable for amphibians and rep- of the Laboratory of Functional Ecology at Cornell University tiles can be difficult. Domestic animals used in biomedi- in Ithaca, New York. cal research have been bred to prosper under conditions Volume 33, Number 4 Fall 1991 S5 that can easily be maintained in an animal room. Am- and Jones (1987), and Pough et al. (1989) and the refer- phibians and reptiles, on the other hand, are wild ani- ences therein. mals, and the husbandry methods applied to them must take this into account. Housing, food, and care must match the physical and behavioral needs of each species. Distinctive Characteristics Carefully designed physical and biological environments are often needed, especially when the goal of husbandry Two attributes of amphibians and reptiles underlie all is to facilitate studies of complex responses such as hor- aspects of their care: Ectothermy and diversity. monal cycles, reproductive and social behavior, or water Downloaded from https://academic.oup.com/ilarjournal/article-abstract/33/4/S1/744425 by Serials Biomed Library 0699 user on 03 January 2019 and temperature regulation. The welfare of the animals Ectothermy. Amphibians and reptiles are ectotherms, must have the highest priority in the design of animal that is, they do not ordinarily generate enough metabolic rooms, cages, and cage furnishings. This effort must not heat to raise their body temperatures above the ambient be frustrated by the application of inappropriate stan- temperature. However, ectotherms are not literally "cold dards based on domestic species. blooded." Under normal conditions, terrestrial ectotherms Because most species of amphibians and reptiles are regulate body temperature by behavioral means, often at not available on short notice or from commercial breed- high levels and within narrow limits. Several important ing colonies, they are usually either collected from the implications for their care follow from this aspect of wild by the investigators themselves, or obtained by gift their biology. Most importantly, they require environ- from other researchers, zoos, or agencies such as the mental conditions quite different from those appropriate U.S. Fish and Wildlife Service. The availability of a for birds and mammals. species is likely to be affected by its seasonal activity Ectothermy is an energy-efficient mode of thermo- cycle, the opportunity to collect in an exotic locality, and regulation because metabolic energy is not used to warm the provisions of national laws and international treaties. the body. As a result, the resting metabolic rates, aerobic An investigator who plans to travel thousands of miles capacities, and overall energy needs of ectotherms are cannot predict in advance exactly how many individuals nearly an order of magnitude lower than those of endo- of which species will be collected. As a consequence of therms (birds and mammals) of similar size (Figure 1). this uncertainty, investigators may have to submit proto- The thermoregulatory mechanisms employed by am- cols that include several taxa, only a few of which will phibians and reptiles are by no means simple. Many ecto- actually be used. Furthermore, unusual species that have been successfully acclimated to laboratory conditions have a scientific value that transcends the project for which they were originally collected, and they may be kept indefinitely in expectation of further use. Animal care and use committees must understand these practical as- pects of working with amphibians and reptiles and evaluate protocols accordingly. THE BIOLOGY OF AMPHIBIANS AND REPTILES In order to design appropriate environments for amphib- ians and reptiles, one must have an appreciation for their unique biological characteristics. Some practices and I 0 g 100 g materials that are suitable and desirable for the care of BODY MASS birds and mammals are unimportant or even deleterious for amphibians and reptiles. Conversely, considerations FIGURE 1 Resting metabolic rates of terrestrial vertebrates that have little