Biography:

In the past Laurie J. Vitt has collaborated on articles with Fred A. Johnson. One of their most recent publications is Chapter 6 - Water Balance and Gas Exchange. Which was published in journal .

More information about Laurie J. Vitt research including statistics on their citations can be found on their Copernicus Academic profile page.

Laurie J. Vitt's Articles: (13)

Chapter 6 - Water Balance and Gas Exchange

Publisher SummaryAmphibians and reptiles live in environments varying from xeric deserts to montane cloud forests and from fresh to saltwater, each of which presents special challenges for the maintenance of osmotic balance. The reactions occur in an active amphibian or reptile require an aqueous medium, and further, water and oxygen are required to convert fuel to usable energy. These metabolic reactions power the chemistry of digestion, absorption, waste removal, cell repair and division, reproduction, and a multitude of other functions. To survive, amphibians and reptiles must maintain internal body fluids that provide a stable environment for the cells. Most amphibians and reptiles maintain homeostasis, but a few species can tolerate high plasma solute concentrations for extended time periods (anhomeostasis). For those living in water, the external environment contains a complement of dissolved ions similar to their bodies but in different proportions. Many aspects of water gain and loss differ in amphibians and reptiles, primarily because of the structure and permeability of the skin. Amphibian skin is unique among vertebrates because it is highly permeable and lacks any kind of structures—scales, feathers, or fur—to make it less permeable. Consequently, water balance is the major physiological issue for amphibians, and evaporative water loss is one of the most important mechanisms for thermoregulation. Unlike amphibians, most reptiles gain or lose almost no water through their impermeable skin, which is largely resistant to movement of water or ions. Water loss and gain must remain in balance, and reptiles lose and gain water in several ways.

Chapter 8 - Spacing, Movements, and Orientation

Publisher SummaryThis chapter focuses on spacing, movement, and orientation of amphibians and reptiles. Within species, both intrinsic (age, life history stage, size, sex, and reproductive status) and extrinsic (environmental quality, season, temperature, and humidity) factors contribute to the patterns of movement. Movements are critical for locating food and mates and avoiding environmental extremes and predators. Within species, individuals often move within an area that they do not defend from conspecifics, called the “home range.” Movements and home ranges of reptiles and amphibians vary considerably, both among and within species. Home ranges can and often do vary through time or space; they can change radically following single events. For some species they may not even exist. Home ranges are not defended, and other individuals may use parts of them. Overlap in home ranges among individuals can be considerable. In amphibians and reptiles, when territoriality occurs, males are most often territorial and females are not. In a few species, females defend a territory as well. Most often, territories defended by males contain females whose home ranges are included within the male territory. Because territoriality allows individuals to maintain control over resources, it involves competition among individuals within species for resources that ultimately contribute to individual fitness. Moreover, spacing typically implies the spatial distribution of individuals within a species and, more specifically, within a local population. As a result, spacing usually focuses on home ranges and territories. Orientation can involve visual, olfactory, auditory, or even magnetic cues, each of which requires a different system for reception. It requires some sort of map and a compass.

Chapter 14 - Conservation Biology

Publisher SummaryConservation biology has emerged as a true scientific discipline and has succeeded in providing an understanding of many of the underpinnings of the field, including effects of pollution on populations of plants and animals, how to approach restoration of various habitats, how to manage endangered species, and many other topics too numerous to mention. Subdisciplines within conservation biology, including conservation genetics, restoration ecology, landscape ecology, and many others, have developed in recent years. A major focus of conservation biology is the maintenance of the world's biodiversity. Biological diversity is the product of organic evolution, and biological processes from the molecular level involving DNA to the biosphere are not intelligible without reference to organic evolution. It includes the genetic diversity embodied in these organisms, and the interactions among them that form unique communities and ecosystems. The study of biodiversity and its conservation require addressing diversity at several levels and in several ways. In addition to assessing the diversity of amphibians and reptiles, herpetological research contributes broadly to conservation management, both in identifying the causes of decline and in developing data on amphibian and reptilian biology, from genetics to natural history.

Chapter 18 - Turtles

Publisher SummaryTurtles are renowned for a slow, plodding locomotion that is more imaginary than real. Turtle life histories are characterized by slow growth, late maturity, repeated reproduction, and long lives. Because of these life history traits, harvesting of adult turtles by humans has a major impact on turtle populations, thus many species and populations are declining toward extinction. Turtles (testudines) are reptilian tanks, armored above and below, and capable of withdrawing the head and neck, limbs, and tails either partially or fully within the shell. Extant turtles are divided into two clades based on the movement or retraction pattern of the neck. All turtles are oviparous. The number of eggs deposited by females of different species ranges from 1 to more than a 100. Most turtles have a stereotypic nest-digging behavior. Living and extinct turtles share a large suite of unique characteristics. No one questions the monophyly of turtles, although the origin of turtles is controversial. In addition to the uniquely evolved carapace and plastron, all testudines share a special cranial architecture that includes the presence of a maxillary, a premaxillary, and a dentary without teeth and bearing a horny sheath; the absence of a postparietal, postfrontal, and ectopterygoid; a small or absent lacrimal; a large quadrate that abuts the squamosal to form the temporal surface of the skull; and a rodlike stapes without a foramen or processes.

Chapter 20 - Tuataras and Lizards

Publisher SummaryThis chapter focuses on two groups of reptile—namely, sphenodontidans and squamates. The chapter describes taxonomic accounts, such as classification, characteristics, and geographical distribution of several taxon of these two groups and also describes lizards. The chapter defines squamata and sphenodontidans. Squamates have more than 50 shared-derived features attesting to their monophyly. The sphenodontidans and squamates apparently diverged in the early Late Triassic, and the sphenodontidans seemingly have always been a group with low diversity. Sphenodontidans and squamates comprise the Lepidosauria. Lepidosaurs share numerous derived characteristics, including a transverse cloacal opening (the vent), tongue notched distally and used to capture prey (lingual prehension), full-body ecdysis, imperforate stapes, teeth attached superficially to the jaw bones, pelvic bones fused in adults, fracture planes or septa in the caudal vertebrae, and numerous other anatomical traits. Sphenodontidans differ from squamates by the presence of gastralia; a narrow quadrate with greatly reduced or lateral concha; lower temporal fenestra enclosed or partially so; jugal in the mid-temporal arch touching the squamosal posteriorly; prominent coronoid process on the mandible; several anterior teeth of the palatine series enlarged; dentary and mandibular teeth generally enlarged, regionalized, and fused to dorsal margin of bone; and the premaxillary teeth replaced by chisel-shaped extensions of the premaxillary bones that have given rise to the tuatara's other vernacular name, half-beaks.

Chapter 2 - Anatomy of Amphibians and Reptiles

Abstract:Amphibian and reptile anatomy is summarized from fertilization and development to glands and organ systems. Some of the major topics addressed include 1) the reproductive system, embryogenesis, morphogenesis, regulation of development, and embryonic lifestyles; 2) hatching, metamorphosis, and growth; and 3) organ systems. In addition to describing anatomy, functional aspects of organ systems are emphasized to present a perspective on how these systems work in amphibians and reptiles.

Chapter 4 - Reproduction and Life Histories

Abstract:Beginning with structure of sperm and gametes, the process of reproduction in amphibians and reptiles is summarized with examples that reveal the diversity of processes involved. A summary of mating and nesting behaviors leads into a discussion of sex determination, number and size of offspring, and seasonality of reproduction. Although most amphibians and reptiles reproduce sexually, some fascinating examples of unisexual reproduction are discussed. Energy invested in reproduction (reproductive effort) has potential survival costs. Taken together, all of these factors have produced considerable variation in life histories of these animals.

Chapter 14 - Conservation Biology

AbstractConservation of amphibian and reptile populations has been extensively studied during the last 20 years; however, questions remain about the lack of success in translating academic studies to real-world actions that lead to saving species. Numerous reasons for this situation are discussed, including lack of funds, growth-based economies in most countries, and the dramatically increasing human population. Advancements in the field of genetics have lead to an increasing understanding of diversity and causes of declines in amphibians and reptiles. Phylogenetic relationships have changed dramatically as a result of DNA studies, leading to the discovery of many unknown species and descriptions of new families. Genetic studies contribute to the studies of viruses and other diseases, at times pinpointing the origin of an outbreak. The single greatest threat to amphibian and reptile populations remains habitat destruction and modification by humans as our numbers increase. Examples of numerous ways humans are impacting populations are discussed, including agricultural practices, logging, pollution, climate change, and various activities that occur outside reserves that impact presumably protected populations. Invasive species are a major threat, and numerous examples of harm done to and by amphibians and reptiles are given.

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AnalysisExpert Elicitation, Uncertainty, and the Value of Information in Controlling Invasive Species

AbstractWe illustrate the utility of expert elicitation, explicit recognition of uncertainty, and the value of information for directing management and research efforts for invasive species, using tegu lizards (Salvator merianae) in southern Florida as a case study. We posited a post-birth pulse, matrix model in which four age classes of tegus are recognized: hatchlings, 1 year-old, 2 year-olds, and 3 + year-olds. This matrix model was parameterized using a 3-point process to elicit estimates of tegu demographic rates in southern Florida from 10 herpetology experts. We fit statistical distributions for each parameter and for each expert, then drew and pooled a large number of replicate samples from these to form a distribution for each demographic parameter. Using these distributions, as well as the observed correlations among elicited values, we generated a large sample of matrix population models to infer how the tegu population would respond to control efforts. We used the concepts of Pareto efficiency and stochastic dominance to conclude that targeting older age classes at relatively high rates appears to have the best chance of minimizing tegu abundance and control costs. We conclude that expert opinion combined with an explicit consideration of uncertainty can be valuable in conducting an initial assessment of what control strategy, effort, and monetary resources are needed to reduce and eventually eliminate the invader. Scientists, in turn, can use the value of information to focus research in a way that not only increases the efficacy of control, but minimizes costs as well.

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