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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Ontogeny and metamorphosis in the Dover sole (Microstomus pacificus) : a description of the early life history stages, with comments on the sister-group relationship between Microstomus and Embassichthys

Harris, Phillip M. 29 May 1992 (has links)
The early life history stages and metamorphosis in Dover sole (Microstomus pacificus) are described from 201 larvae and juveniles. Unlike other pleuronectids, with the possible exception of the deep-sea sole (Embassichthvs bathvbius), initial migration of the left eye is not associated with metamorphosis or transition from plankton to benthos. The left eye exhibits a stasis during its migration, so that premetamorphic larvae are optically asymmetrical while planktonic. Seven characters are used to quantify the progress of metamorphosis: completed eye migration, dorsal fin position, dentition, pectoral fin development, condition of posterior process of coracoid, pigmentation, and elongation of the intestine into a secondary body cavity. Other characters associated with metamorphosis are reduction in body depth associated with reductions in lengths of neural and hemal spines and associated dorsal- and anal- fin pterygiophores, decreasing interorbital distance, increasing right eye diameter and right premaxilla length, and development of body scales. Metamorphosis appears to require 9- 11 or 12 months to complete. The planktonic period of premetamorphic and metamorphic larvae is about 18-24 months. Metamorphic larvae appear to move inshore into shallower water as metamorphosis progresses. Settlement occurs from about December to April, primarily from January to March. One of the earliest phylogenetic hypotheses about the intergeneric relationships of the pleuronectid genera Microstomus, Embassichthys, Glyotocephalus, and Tanakius was by Norman (1934), who considered Microstomus plus Embassichthvs and Glyotocephalus plus Tanakius to be sister groups. An alternative hypothesis by Richardson (1981) suggested that Embassichthvs larvae resembled larvae of Glyptoceohalus and Tanakius based on a "leptocephaluslike" body shape, and that Microstomus was the primitive sister group of these three genera because of its dorsoventrally deepened body shape. In order to evaluate Richardson's hypothesis of sister group relationships based on body shape, I examined morphological characters associated with eye migration and metamorphosis, and changes in body shape during ontogeny from post-flexion larvae through benthic juveniles. Richardson's-character of a moderate "leptocephalus-like" body shape is an artifact of the paucity and small size range of larvae available for her examination. The body shape of larger Embassichthvs larvae is also dorsoventrally deepened and the larvae appear to undergo changes in body shape during metamorphosis similar to Microstomus. Three synapomorphies that support Norman's hypothesis of an Embassichthys plus Microstomus sister group relationship are dissociation of initial eye migration with metamorphosis, a stasis during eye migration in premetamorphic larvae, and a retention of a larval-like appearance to the eyes of newly settled specimens. / Graduation date: 1993
2

An introductory population study of the Gecko, Hoplodactylus pacificus, on Quail Island, in the Lyttleton Harbour.

McIvor, Ian Richard January 1970 (has links)
The common gecko, Hoplodactylus pacificus (Gray, in McCann (1955) ), is widely distributed throughout New Zealand. As yet no specific ecological study of this lizard has been published, though Sharell (1966) mentions habitat preferences and hibernation behaviour, and Whitaker (1968) has published some data for H. pacificus on Poor Knights Islands (mentioned in this report) and describes their observed foraging behaviour. In this study, carried out from late March through to May 1970, I have recorded information on snout-vent lengths, weights, individual movements, and habitat preference, and have also estimated the population density. This particular lizard does not seem to be active during the Autumn months and no observations of food preferences and foraging behaviour were able to be made.
3

An introductory population study of the Gecko, Hoplodactylus pacificus, on Quail Island, in the Lyttleton Harbour.

McIvor, Ian Richard January 1970 (has links)
The common gecko, Hoplodactylus pacificus (Gray, in McCann (1955) ), is widely distributed throughout New Zealand. As yet no specific ecological study of this lizard has been published, though Sharell (1966) mentions habitat preferences and hibernation behaviour, and Whitaker (1968) has published some data for H. pacificus on Poor Knights Islands (mentioned in this report) and describes their observed foraging behaviour. In this study, carried out from late March through to May 1970, I have recorded information on snout-vent lengths, weights, individual movements, and habitat preference, and have also estimated the population density. This particular lizard does not seem to be active during the Autumn months and no observations of food preferences and foraging behaviour were able to be made.
4

Ecology of a population of hoplodactylus pacificus, the common New Zealand gecko (reptilia:gekkonidae)

McIvor, Ian Richard January 1972 (has links)
This study was intended to provide information on certain aspects of the population ecology of H. pacificus. A population on Quail Island in Lyttelton Harbour was chosen for intensive study over a period of one year. Some information on the population was already available. derived from a preliminary study in 1970 (McIvor, 1970a). The following aspects were investigated; population density, natality and mortality, age structures and sex ratios, annual and seasonal growth, daily and seasonal activity, reproduction (detailed investigation of testicular activity), home range and movements and diet. Much of the population information was obtained from recapture of marked individuals. This study helps to fill some of the major gaps in our knowledge of the biology of the nocturnal gecko. Hoplodactylus pacificus.
5

Ecology of a population of hoplodactylus pacificus, the common New Zealand gecko (reptilia:gekkonidae)

McIvor, Ian Richard January 1972 (has links)
This study was intended to provide information on certain aspects of the population ecology of H. pacificus. A population on Quail Island in Lyttelton Harbour was chosen for intensive study over a period of one year. Some information on the population was already available. derived from a preliminary study in 1970 (McIvor, 1970a). The following aspects were investigated; population density, natality and mortality, age structures and sex ratios, annual and seasonal growth, daily and seasonal activity, reproduction (detailed investigation of testicular activity), home range and movements and diet. Much of the population information was obtained from recapture of marked individuals. This study helps to fill some of the major gaps in our knowledge of the biology of the nocturnal gecko. Hoplodactylus pacificus.
6

Physiological Factors Affecting the Bactericidal Activity of the Western Fence Lizard (Sceloporus occidentalis) for the Lyme Disease Spirochete, Borrelia burgdorferi

Weichert, Kyle Russell 01 June 2015 (has links) (PDF)
The Western Fence Lizard (Sceloporus occidentalis) is a major host of juvenile stages of the Western Black-legged Tick (Ixodes pacificus), which is the vector for the Lyme disease causative spirochete bacterium Borrelia burgdorferi in the western United States. Because S. occidentalis is reservoir incompetent and capable of eliminating spirochetes from infected ticks, it has been implicated as a major factor in the ecology of Lyme disease in the West. Although complement proteins in lizard blood have been established as the borreliacidal factor, no studies have examined intraspecific variability in host lizard borreliacidal capacity. In Chapter 1 of this thesis, we introduce the complexity of the Borrelia burgdorferi transmission cycle and it’s implications for transmission risk. In Chapter 2 we tested the hypothesis that host lizard physiological condition impacts their borreliacidal capacity. Blood plasma of lizards in varying physiological conditions was challenged against cultured B. burgdorferi, and the complement-mediated inactivation of spirochetes was quantified. Adult lizards had higher bactericidal activity than first-year juveniles, suggesting that complement-mediated inactivation develops with maturity and/or exposure to spirochete antigens. Also, bactericidal activity was positively associated with lizard tick load and body condition. Adult lizard sex did not significantly affect spirochete mortality. Lizards from an inland site with little exposure to ticks had higher bactericidal activity than lizards from a coastal population that is heavily parasitized by ticks.
7

Settlement, distribution, growth, and mortality of juvenile dover sole (Microstomus pacificus) off northern Oregon

Toole, C. L. (Christopher L.) 04 May 1994 (has links)
Demographic characteristics of juvenile Dover sole (Microstomus pacificus) were examined in relation to physical and biotic factors to develop a hypothesis explaining annual variations in recruitment. Surveys were conducted along the Oregon continental shelf at depths between 50-400 m bimonthly during 1989 and annually (in March) between 1990 and 1993. To determine settlement timing, growth, and mortality, daily growth increments were validated, as was position of the first post-settlement annulus. A method of estimating precision of otolith elemental composition with the electron microprobe was developed; otolith microstructure and microchemistry were used to identify a landmark associated with settlement. Mean density of 0-group settlers varied annually, with 1989 and 1990 high, 1991 and 1992 low, and 1993 intermediate. 0-group abundance was correlated with fall offshore divergence one year before settlement and with southward geostrophic velocity during the summer before settlement. These conditions may be related to production of prey available to pelagic larvae. Density of 0-group Dover sole was highest between 100-119 m, but deeper areas were also utilized in years of highest abundance. Density was not correlated with spawning stock biomass or density of older juveniles. It was correlated with rex sole (Glyptocephalus [Errex] zachirus) density. Growth rate was positively correlated with mean April-October upwelling and was not related to density or mortality of Dover sole. First-year mortality was positively correlated with early settlement of 0-group larvae, possibly due to an advantage of settling and migrating to the primary nursery area well in advance of the spring transition. A multiple regression model predicting density of 1-group Dover sole from three physical environmental factors was applied to an independent time series of Dover sole "age-5" recruitment estimates (Turnock and Methot 1992). The model was a poor predictor of annual recruitment to fisheries but a good predictor of trends based on five-year running averages. Results suggest that multi-year trends in Dover sole recruitment to fisheries can be explained by a small set of density-independent physical factors. / Graduation date: 1995
8

Authentication of Stemona root, oilfish, crocodile meat and frog oviduct.

January 2008 (has links)
Ling, Ka Ho. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 124-157). / Abstracts in English and Chinese. / Acknowledgement --- p.ii / Abstract --- p.iv / 摘要 --- p.vii / Table of content --- p.ix / List of figures --- p.xiii / List of tables --- p.xv / Abbreviations --- p.xvi / Chapter 1 --- Food authentication --- p.1 / Chapter 1.1 --- Introduction and definition --- p.1 / Chapter 1.2 --- Importance of species identification in food authentication --- p.3 / Chapter 1.3 --- Methods for species identification in food authentication --- p.8 / Chapter 1.4 --- Legislation --- p.17 / Chapter 1.5 --- Objectives --- p.19 / Chapter 2 --- Molecular authentication and antitussive bioassay of Stemona root (Baibu) and root of Asparagus filicinus (Xiao-baibu) --- p.20 / Chapter 2.1 --- Introduction --- p.20 / Chapter 2.2 --- Materials and methods --- p.22 / Chapter 2.3 --- Results --- p.34 / Chapter 2.4 --- Discussion --- p.40 / Chapter 2.5 --- Conclusions --- p.44 / Chapter 3 --- Rapid detection of oilfish and escolar in fish steaks: a tool to prevent keriorrhea episodes --- p.45 / Chapter 3.1 --- Introduction --- p.45 / Chapter 3.2 --- Materials and methods --- p.49 / Chapter 3.3 --- Results --- p.59 / Chapter 3.4 --- Discussion --- p.69 / Chapter 3.5 --- Conclusions --- p.75 / Chapter 4 --- Widespread adulteration of crocodile meat with python and water monitor meats --- p.76 / Chapter 4.1 --- Introduction --- p.76 / Chapter 4.2 --- Materials and methods --- p.78 / Chapter 4.3 --- Results --- p.89 / Chapter 4.4 --- Discussion --- p.96 / Chapter 4.5 --- Conclusions --- p.100 / Chapter 5 --- Authentication of dried and ready-to-eat hashima products --- p.101 / Chapter 5.1 --- Introduction --- p.101 / Chapter 5.2 --- Source species of hashima --- p.103 / Chapter 5.3 --- Materials and methods --- p.106 / Chapter 5.4 --- Results --- p.116 / Chapter 5.5 --- Discussion --- p.119 / Chapter 5.6 --- Conclusions --- p.121 / Chapter 6 --- General conclusions --- p.122 / Chapter 6.1 --- Key findings --- p.122 / Chapter 6.2 --- Applications and implications --- p.123 / Chapter 7 --- References --- p.124

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