Author: Tag Nicholas EngstromPublisher:
ISBN:
Category :
Languages : en
Pages : 302
Book Description
Molecular Studies of Phylogenetics, Ecology and Conservation of Softshell Turtles (family Trionychidae) and Amazon River Turtles (Podocnemis Unifilis)
Author: Tag Nicholas EngstromPublisher:
ISBN:
Category :
Languages : en
Pages : 302
Book Description
Molecular Studies of Phylogenetics, Ecology and Conservation of Softshell Turtles (family Trionychidae) and Amazon River Turtles (Podocnemis Unifilis)
Author: Tag Nicholas EngstromPublisher:
ISBN:
Category :
Languages : en
Pages : 302
Book Description
The Ecology, Exploitation and Conservation of River Turtles
Author: Don MollPublisher: Oxford University Press
ISBN: 0195102290
Category : Mathematics
Languages : en
Pages : 408
Book Description
The underlying theme of this book is that a widespread, taxonomically diverse group of animals, important both from ecological and human resource perspectives, remains poorly understood and in delcine, while receiving scant attention from the ecological and conservation community. This volume proposes a comprehensive overview of the world's river turtles' ecology, conservation, and management. It begins with a categorization of taxa which inhabit flowing water habitats followed by information on their evolutionary and physical diversity and biogeography. Within the framework of ecology, the authors discuss the composition of river turtle communities in different types of lotic habitats and regions, population dynamics, movements, reproductive characteristics and behavior, predators, and feeding relationships. In a conservation and management section, the authors identify and evaluate the nature and intensity of factors which threaten river turtle survival--almost all of which involve direct human exploitation or indirect effects of human induced habitat alteration and degradation. They then list and evaluate the various schemes which have been proposed or employed to halt declines and restore populations, and make recommendations for future management plans for specific species and regions. In closing, they state their viewpoint concerning future research directions and priorities, and an evaluation of future prospects for survival of the world's river turtle species.
Molecular Phylogenetics and Conservation of Freshwater Turtles
Author: Phillip Quinton SpinksPublisher:
ISBN:
Category :
Languages : en
Pages : 146
Book Description
Dissertation Abstracts International
Author: Publisher:
ISBN:
Category : Dissertations, Academic
Languages : en
Pages : 854
Book Description
The Molecular Evolution of Non-Coding DNA and Population Ecology of the Spiny Softshell Turtle (Apalone Spinifera) in Lake Champlain
Author: Lucas E. BernackiPublisher:
ISBN:
Category :
Languages : en
Pages : 312
Book Description
ABSTRACT Spiny softshell turtles (Apalone spinifera) occur at the northwest limit of their range in Lake Champlain. This species, although widespread across North America, is listed as threatened in Vermont due to habitat destruction and disturbances of anthropogenic origin. The population of spiny softshell turtles in Lake Champlain is isolated from other North American populations and is considered as an independent management unit. Efforts to obtain information on the biology of spiny softshell turtles in Lake Champlain precede 1936 with conservation measures being initiated in 1987. Methods of studying spiny softshell turtles in Lake Champlain have included direct observation, mark-recapture, nest beach monitoring, winter diving, and radio telemetry. Each of these approaches has provided some information to the sum of what is known about A. spinifera in Lake Champlain. For example major nesting beaches, hibernacula, and home range size have been determined. Currently spiny softshell turtles primarily inhabit two areas within Lake Champlain, Missisquoi Bay and the mouth of the Lamoille River. However, the population structure and gene flow between spiny softshell turtles inhabiting the Lamoille and Missisquoi regions remained unknown. A GIS model was created and tested in order to identify additional nesting beaches used by spiny softshell turtles along the Vermont shores of Lake Champlain. Although some additional small potential nesting beaches were found, no additional major nesting sites were found. The GIS model identified the mouth of the Winooski River (the site of a historical population) as potentially suitable nesting habitat; however, no evidence of spiny softshell turtle nesting was found at this site. A series of methods developed for collecting molecular and population genetic data about spiny softshell turtles in Lake Champlain are described, including techniques for DNA extraction of various tissue types and the design of new primers for PCR amplification and sequencing of the mitochondrial control region (mtD-loop). Techniques for circumventing problems associated with DNA sequence alignment in regions of a variable numbers of tandem repeats (VNTRs) and the presence of heteroplasmy within some individuals are also described. The mtD-loop was found to be a suitable marker to assess the genetic structure of the Lake Champlain population of spiny softshell turtles. No significant genetic sub-structuring was found (FST=0.082, p=0.223) and an indirect estimate of the migration rate between Lamoille and Missisquoi regions of Lake Champlain was high (Nm>5.576). In addition to consideration of A. spinifera in Lake Champlain, the mtD-loop was modeled across 46 species in 14 families of extant turtles. The primary structure was obtained from DNA sequences accessed from GenBank and secondary structures of the mtD-loop were inferred, (from thermal stabilities) using the program Mfold, for each superfamiliy of turtles. Both primary and secondary structures were found to be highly variable across the order of turtles; however, the inclusion of an AT-rich fold (secondary structure) near the 3' terminus of the mtD-loop was common across all turtle families considered. The Cryptodira showed conservation in the primary structure at regular conserved sequence blocks (CSBs), but the Pluerodira displayed little conservation in the primary structure of the mtD-loop. Overall, greater conservation in secondary structure than primary structure was observed in turtle mtD-loop. The AT-rich secondary structural element near the 3' terminus of the mtD-loop may be conserved across turtles due to it serving a functional role during mtDNA transcription.
The Phylogenetic Relationships of Soft-shelled Turtles (family Trionychidae)
Author: Peter Andre MeylanPublisher:
ISBN:
Category : Reptiles
Languages : en
Pages : 101
Book Description
Phylogenetic analysis of nearly one hundred characters of the osteology of trionychid turtles provides abundant data on the phyletic relationships of this family to other turtles and on the interrelationships of its members. These data suggest that the family Trionychidae shares a unique common ancestor with the Dermatemydidae, Kinosternidae and Carettochelyidae , and that the Kinosternidae shares a unique common ancestor with the Trionychidae and Carettochelyidae. Furthermore, it is the staurotypine kinosternids that are most closely related to the Trionychidae and Carettochelyidae. Carettochelyids and trionychids share numerous unique features and constitute a monophyletic group . Within the Trionychidae, the subfamilies Cyclanorbinae and Trionychinae are recognized as monophyletic clades. Recognition of three cyclanorbine genera, Cycloderma , Cyclanorbis and Lissemys , is warranted. Within the Trionychinae, four distinct clades are recognized. The Trionyx cartilaglneus group includes Chitra indica and Pelochelys bibroni on the basis of the unique location of the foramen posterior canalis carotici interni, and features of the trigeminal region. The North American group, which includes T. triunguis , T. euphraticus , T. swinhoei , T. ferox , T. spiniferus and T. muticus, can be recognized by the presence of eight or fewer neurals (first and second are fused), deeply emarginate prefrontals and a large contribution by the parietal to the processus trochlearis oticum. The Indian group includes four species: T. gangeticus , T. hurum , T. leithii and T. nigricans . All exhibit a free first neural, five plastral callosities and intermediately extended epiplastra. Lastly, the T. steindachneri group is diagnosed by a descending spine of the opisthotic which divides the fenestra postotica in most specimens. Two equally parsimonious arrangements of the Trionychinae differ in the placement of the North American clade. In one, this clade is the sister group of the T. cartilagineus clade; in the other it is the sister group of the T. steindachneri clade. In both, the Indian group is paraphyletic and gives rise to the T. steindachneri clade. A tentative revision of the classification of the family Trionychidae is provided. In it, five generic names currently in the synonymy of Trionyx are resurrected to denote unique clades of trionychine turtles.
PHYLOGENETIC RELATIONSHIPS OF THE SOFT-SHELLED TURTLES (FAMILY TRIONYCHIDAE.).
Author: Phylogenetic Relationships of the Soft-shelled Turtles (family Trionychidae)
Author: Peter Andre MeylanPublisher:
ISBN:
Category : Soft-shelled turtles
Languages : en
Pages : 200
Book Description
Author: Peter André Meylan