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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.

Die voortplantingsbiologie, teelt en hormoongeinduseerde geslagsverandering van vier Tilapiasoorte

17 November 2014 (has links)
M.Sc. / Please refer to full text to view abstract

Biochemistry and physiology of growth hormone in tilapia.

January 1990 (has links)
by Leung Tin Chung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1990. / Bibliography: leaves 123-138. / Abstract --- p.i / Acknowledgements --- p.iv / List of Abbreviations --- p.V / Objectives of the study --- p.vi / Table of contents --- p.vii / Chapter Chapter 1 --- General Introduction --- p.1 / Chapter Chapter 2 --- Metabolic effects of bovine growth hormone on tilapia --- p.11 / Introduction --- p.11 / Materials and Methods --- p.14 / Results --- p.20 / Discussion --- p.22 / Chapter Chapter 3 --- Characterization of growth hormone-binding sites in tilapia --- p.25 / Introduction --- p.25 / Materials and Methods --- p.27 / Results --- p.34 / Discussion --- p.66 / Chapter Chapter 4 --- Characterization of somatomedin C-like immunoreactivity in tilapia --- p.75 / Introduction --- p.75 / Materials and Methods --- p.81 / Results --- p.85 / Discussion --- p.93 / Chapter Chapter 5 --- Effects of salinity and diet on somatic growth and secretion of hormones in tilapia --- p.97 / Introduction --- p.97 / Materials and Methods --- p.102 / Results --- p.105 / Discussion --- p.114 / Chapter Chapter 6 --- General discussions --- p.121 / References --- p.123

'n Vergelykende studie van die kariotipes van Tilapia rendalli, T. sparrmanii en Oreochromis mossambicus (Cichlidae)

Swanepoel, Antoinette 17 November 2014 (has links)
M.Sc. / Please refer to full text to view abstract

Growth regulation in the euryhaline tilapia, Oreochromis mossambicus effects of gonadal steroid hormones and salinity on the growth hormone/insulin-like growth factor-I axis /

Riley, Lawrence G. January 2003 (has links)
Thesis (Ph. D.)--University of Hawaii at Manoa, 2003. / Includes bibliographical references (leaves 97-121).

A contribution to the biology of Tilapia mossambica Peters in Lake Sibaya, South Africa

Bruton, Michael N January 1973 (has links)
An account is given of some aspects of the biology of Tilapia mossambica Peters in Lake Sibaya, South Africa. Previous work on Tilapia in Lake Sibaya is reviewed. Apart from brief gillnet surveys, which recorded the species' presence, no research on T. mossambica had been performed at Lake Sibaya before the two-year study of Minshull who collected data on food preferences, depth distribution of juveniles and breeding biology of adults. The main physiographical features of the lake are outlined. Lake Sibaya is a warm shallow coastal lake with extensive shallow terraces in the littoral which shelve abruptly into underwater valleys. The substrate is predominantly sandy. Aquatic macrophytes are generally restricted to water 1-7 m deep. Adult fishes (over 8 cm SL) are usually absent from water deeper than 12 m and shallower than 0.5 m, whereas juveniles may occur at all depths, and fry only in very shallow water. T. mossambica inhabits the littoral in the warm and transition periods (August to April) but moves into deep water in the cool season (May to July). Exposed and sheltered shallow areas are utilised for different purposes by adult fishes, the former for nesting, and the latter for feeding and mouth-brooding. Habitat selection by males was governed by nest site selection. Habitat Nests were most common in sheltered, sparsely vegetated littoral and sublittoral areas, but also present in well-vegetated sheltered areas. Breeding females preferred sheltered littoral areas but ventured onto the terrace to release the young. Juvenile and fry T. mossambica inhabited shallow exposed shores with a temperature gradient which reversed diurnally. The breeding, shoaling and feeding behaviour of T. mossambica is described, and integrated with data on T. mossambica from other systems. The breeding season spans seven months. Shoaling takes place in shallow water probably as a means of protection. T. mossambica is an omnivorous feeder relying largely on diatoms. The main predator is probably the barbel Clarias gariepinus, but avian predators may be more important. A method whereby the time of formation of rings on the scales of T. mossambica is described. The fishes were found to reach maturity after one year at a length of about 8 cm in females, and after two years at 10 cm in males. The breeding population had a standard length mode of 14 cm (females) and 17 cm (males). The maximum final size was about 24 cm SL. An estimate of the standing crop for fishes in the littoral and subiittoral areas of the eastern and southern shores of the south basin is given. The data were derived from a mark and recapture The biology of T. mossambica in Lake Sibaya as revealed by the present study is discussed with reference to data on the same and similar species in other systems. The utilis ation of the available resources in the lake by T. mossambica is commented upon, and reference is made to the significance of stunting, and the import ance of the retention of generalised characters for the successful habitation of the cyclically-renewed habitat of the littoral. Precocious breeding in T. mossambica is regarded as a functional adaptation which increases the proportion of fishes small enough to utilise the rich food resources in shallow water.

'n Morfometriese en elektroforetiese evaluering van die twee subspesies van Tilapia rendalli in suidelike Afrika

17 November 2014 (has links)
M.Sc. / Please refer to full text to view abstract

Pressure induced diploid gynogenesis in Oreochromis niloticus (Cichlidae) following heterologous fertilization

Peruzzi, Stefano January 1993 (has links)
No description available.

The determination of the factors related to the pathology of vibriosis in cultured tilapia

LeaMaster, Brad R January 1991 (has links)
Thesis (Ph. D.)--University of Hawaii at Manoa, 1991. / Includes bibliographical references (leaves 159-175). / Microfiche. / xiii, 175 leaves, bound ill. (some col.) 29 cm

An investigation of the survival level of Oreochromis mossambicus fry variably kept in a closed system : laboratory experiment /

Asgodom, Mihretu T. January 2005 (has links)
Thesis (MPhil)--University of Stellenbosch, 2005. / On t.p.: Master of Philosophy in Livestock Industry Management (Aquaculture) Bibliography. Also available via the Internet.

Implicações do perfil de ansiedade na dinâmica /

Genovez, Lara Wichr. January 2010 (has links)
Orientador: Gilson Luiz Volpato / Resumo: Este estudo investigou o perfil de ansiedade em Juverus de Tilápia-do-Nilo (Ore Niloticus). Num primeiro capitulo, determinamos um perfil comportamental indicativo de níveis de ansiedade. Num segundo capitulo, avaliamos o efeito de diferentes proporções de peixes com ansiedade alta (AA) e pouca (PA) na agressão e na produção de peixes em condições de aquário. No primeiro capitulo, por meio da modulação do comportamento de peixes usando drogas ansiolíticas (Diazepam, DZP) e ansiogênicas (Pentilenotetrazol, PTZ), demonstramos que o tempo gasto na natação foi um indicador confiável do nível de ansiedade (menor a locomoção, maior o nível de ansiedade). Também descobrimos que esse traço comportamental é melhor do que a medida de latência para sair do abrigo e explorar o ambiente novo. No segundo capitulo, outros peixes foram separados pelo critério de locomoção em perfis AA e PA e agrupados (6 peixes/aquário) para observação da agressão, do crescimento, da alimentação e da sobrevivência em 3 proporções: a) 50% de AA + 50% de PA; b) 100% PA e c) 100% AA. Nenhuma das variáveis observadas foi diferente entre essas composições de grupo / Abstract: This study investigated the anxiety profile in Nile tilapia juveniles (Oreochromis niloticus) by determining in a first chapter a behavioral profile to indicate levels of anxiety and, in a second chapter, the effect of different proportion of high (liA) and low (LA) anxiety fish on aggression and fish production in aquarium conditions. ln the first chapter, by modulating fish behavior with ansiolitic (Diazepam DZP) and ansiogenic (pentylenotetrazole PTZ) drugs, we demonstrated that time fish spent in swimming was a reliable indicator of anxiety levei (the lower the swimming, the higher the anxiety levei). We also found that this behavioral trait is better than measure of latency to exit shelter and explore a novel environment. Then, in the second chapter, other fish were separated by the locomotor criterium in HA and LA profiles and grouped (6 fish/aquarium) for aggression, growth, feeding and survival observations at three proportions: a) 50% HA + 50% LA, b) 100% HA, and c) 100% LA. Neither of the observed variables was different among these group compositions / Mestre

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