The development and failure of the Eastern Cape separatist movement with special reference to John Paterson
- Authors: Stead, J L
- Date: 1974
- Subjects: Paterson, John, 1822-1880 , Cape of Good Hope (South Africa) -- Politics and government -- 1795-1872 , Eastern Cape (South Africa) -- History -- Autonomy and independence movements , Stormberg Range Region (South Africa) -- History
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2593 , http://hdl.handle.net/10962/d1007343
- Description: From Preface: In 1960 Pamela Ffolliott and E.L.H. Croft wrote a biograpby of John Paterson entitled One Titan at a Time. This concentrated mainly on his business activities and his civic role to the virtual exclusion of his political opinions and career even though contemporaries often regarded him as second only to John X. Merriman. The result of diligent enquiry for further biographical detail both in South Africa and in the United Kingdom has been disappointing. A close examination of such evidence as there is, suggests that his political abilities have been over-rated rather than under-rated. It is now nearly forty years since the study of separatism was first seriously undertaken. The period 1854-72 was studied by N.H. Taylor (M.A. Thesis, University of Cape Town, 1938) and D.B. Sole undertook a broader survey (M.A. Thesis, University of South Africa (R.U.C.), 1939). Neither study used the Godlonton papers. The Godlonton-White correspondence is at Rhodes House, Oxford and this mainly concerns business matters and news of prominent local people. The collection of Godlonton papers housed in the Historical Papers section of the Library of the University of the Witwatersrand proved more interesting. The use of these papers made it possible to make a new approach to the critical period of representative government and to explore in more detail lines suggested in part by J .L. McCracken in the more general study, The Cape Parliament 1854-1910 published in 1967. Yet because in many cases the leaders of the movement after 1854 carried into the new era ideas and attitudes formed in earlier years, it was necessary to consider also the origins of the separatist impulse. Separatism had many roots: as a term it had many meanings. Clearly the meaning attached to the word varied from time to time, from place to place and even from person to person. The goal varied too. Sometimes the Eastern Province wanted to move the centre of government from Cape Town; sometimes the cry was for a completely separate colony to be established in the East; sometimes the theme was federal devolution of powers, to a resident government. Indeed among the many reasons for the failure of the separatist movement was the inability of the Easterners to agree among themselves about what they were seeking. This exposed and emphasised their political ineptitude.
- Full Text:
- Date Issued: 1974
- Authors: Stead, J L
- Date: 1974
- Subjects: Paterson, John, 1822-1880 , Cape of Good Hope (South Africa) -- Politics and government -- 1795-1872 , Eastern Cape (South Africa) -- History -- Autonomy and independence movements , Stormberg Range Region (South Africa) -- History
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2593 , http://hdl.handle.net/10962/d1007343
- Description: From Preface: In 1960 Pamela Ffolliott and E.L.H. Croft wrote a biograpby of John Paterson entitled One Titan at a Time. This concentrated mainly on his business activities and his civic role to the virtual exclusion of his political opinions and career even though contemporaries often regarded him as second only to John X. Merriman. The result of diligent enquiry for further biographical detail both in South Africa and in the United Kingdom has been disappointing. A close examination of such evidence as there is, suggests that his political abilities have been over-rated rather than under-rated. It is now nearly forty years since the study of separatism was first seriously undertaken. The period 1854-72 was studied by N.H. Taylor (M.A. Thesis, University of Cape Town, 1938) and D.B. Sole undertook a broader survey (M.A. Thesis, University of South Africa (R.U.C.), 1939). Neither study used the Godlonton papers. The Godlonton-White correspondence is at Rhodes House, Oxford and this mainly concerns business matters and news of prominent local people. The collection of Godlonton papers housed in the Historical Papers section of the Library of the University of the Witwatersrand proved more interesting. The use of these papers made it possible to make a new approach to the critical period of representative government and to explore in more detail lines suggested in part by J .L. McCracken in the more general study, The Cape Parliament 1854-1910 published in 1967. Yet because in many cases the leaders of the movement after 1854 carried into the new era ideas and attitudes formed in earlier years, it was necessary to consider also the origins of the separatist impulse. Separatism had many roots: as a term it had many meanings. Clearly the meaning attached to the word varied from time to time, from place to place and even from person to person. The goal varied too. Sometimes the Eastern Province wanted to move the centre of government from Cape Town; sometimes the cry was for a completely separate colony to be established in the East; sometimes the theme was federal devolution of powers, to a resident government. Indeed among the many reasons for the failure of the separatist movement was the inability of the Easterners to agree among themselves about what they were seeking. This exposed and emphasised their political ineptitude.
- Full Text:
- Date Issued: 1974
The doctrine of the holy spirit in pentecostalism and neo-pentecostalism, with special reference to the work of Frederick Dale Bruner
- Authors: Higgs, Michael John
- Date: 1974
- Subjects: Bruner, Frederick Dale Pentecostalism Holy Spirit -- Biblical teaching Baptism in the Holy Spirit
- Language: English
- Type: Thesis , Bachelor , BDiv
- Identifier: vital:1259 , http://hdl.handle.net/10962/d1012269
- Description: The problem of 'authority' is of paramount importance in determining the theological stance of any religious movement and not least is this the case where the movement is labelled 'fundamentalist' both by its protagonists and its antagonists. Intro. p. 1.
- Full Text:
- Date Issued: 1974
- Authors: Higgs, Michael John
- Date: 1974
- Subjects: Bruner, Frederick Dale Pentecostalism Holy Spirit -- Biblical teaching Baptism in the Holy Spirit
- Language: English
- Type: Thesis , Bachelor , BDiv
- Identifier: vital:1259 , http://hdl.handle.net/10962/d1012269
- Description: The problem of 'authority' is of paramount importance in determining the theological stance of any religious movement and not least is this the case where the movement is labelled 'fundamentalist' both by its protagonists and its antagonists. Intro. p. 1.
- Full Text:
- Date Issued: 1974
The ecology of juvenile Rhabdosargus holubi (Steinachner) (Teleostei : Sparidae)
- Authors: Blaber, Stephen J M
- Date: 1974
- Subjects: Osteichthyes Fishes -- Breeding Fish populations Fish culture -- South Africa Estuaries -- South Africa -- Eastern Cape Aquatic ecology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5672 , http://hdl.handle.net/10962/d1005357
- Description: INTRODUCTION: Estuaries have received considerable attention from biologists in southern Africa in the past thirty years. Professor J.H. Day and the Zoology Department of the University of Cape Town have undertaken ecological surveys of a large number of estuaries of a variety of types, laying the important groundwork for more detailed studies of single species or problems. Their studies showed that the fish populations of southern African estuaries consist mainly of marine species. Why and when these species enter or leave the estuaries and whether they grow or breed in them were not established. The only relatively detailed study of a fish in southern African estuaries was that of Talbot (1955) who investigated aspects of the growth, feeding and reproduction of Rhabdosargus globiceps (Cuvier). No quantitative information has been published on any of the fish species, perhaps due to the difficulty of obtaining such data; results such as population estimates, mortality rates and growth rates are particularly unreliable when the area being investigated is in direct contact with the sea. Studies relating to even a single species of fish are hampered by immigration and emigration between estuary and sea, which make the population continuously variable. The larger estuaries are also difficult to sample adequately, especially with regard to netting, except perhaps on a very large scale using expensive commercial equipment. Along the southern African coast many of the smaller estuaries with a limited catchment area are cut off from the sea for most of the year due to erratic rainfall and longshore drift of sand. These closed or 'blind' estuaries of south eastern Africa, of which there are at least thirty in the eastern Cape Province, provide excellent areas for studying estuarine fish populations which enter when the estuary is open to the sea, but become isolated once it closes. These fish which become cut off in closed estuaries are subject to a new series of conditions. They are exposed to the wider temperature and salinity fluctuations of an estuary and they are forced to utilise the food resources of the estuary. Additionally they may be subjected to predation from piscivorous birds, and those predatory fish which are also cut off in the estuary. These factors will affect the size, mortality, and growth rates of a fish population. Since the fish are isolated no recruitment from the sea can take place, and any increase in numbers would have to come from breeding within the estuary. It is inevitable that the most numerous species should receive attention first. Rhabdosargus holubi (Steindachner) (Synonomy : Sargus holubi Stndr, Austrosparus tricuspidens Smith, Rhabdosargus tricuspidens (Smith))(Plate 1) is one of the most abundant fish in the estuaries of the eastern Cape Province. According to Smith (1965) it is endemic to southern Africa, occurring from the Cape to Zululand, being most common between Mossel Bay and East London. It is largely replaced by Rhabdosargus sarba (Forskal) in the north of its range and by Rhabdosargus globiceps (Cuvier) in the south. Commonly called the 'flatty' or silver bream it is considered only as being of nuisance value by fishermen, seldom exceeding 30 cm in length. In this study the ecology of R.holubi was examined in relation to the closed West Kleinemond estuary which is a small 'blind' estuary typical of those found along the eastern Cape coast. The growth, mortality and population size of R.holubi in this estuary were investigated and linked where possible with predation and detailed studies into the tolerances, food, and feeding of the species. It was not known at the commencement of the study whether breeding could occur in estuaries, although Smith (1965) stated that R.holubi does breed in estuaries. During the course of the sampling programme in the West Kleinemond estuary, measurements of the growth and population structure of two other species of fish were recorded for comparison with R.holubi: the sparid Lithognathus lithognathus (Cuvier) (White Steenbras) and the piscivorous carangid Hypacanthas amia (L.) (Leervis or garrick). Laboratory studies on R.holubi were possible due to the fact that large numbers of this species could be caught in eastern Cape estuaries and transported to Grahamstown, where they could be maintained in captivity for up to four months in recirculating seawater aquaria. During the course of the study over 2000 fish were kept in captivity at different times for a variety of experiments. Another 2500 were preserved for gut analyses and lipid determinations, while over 5000 were captured, examined and released in the field.
- Full Text:
- Date Issued: 1974
- Authors: Blaber, Stephen J M
- Date: 1974
- Subjects: Osteichthyes Fishes -- Breeding Fish populations Fish culture -- South Africa Estuaries -- South Africa -- Eastern Cape Aquatic ecology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5672 , http://hdl.handle.net/10962/d1005357
- Description: INTRODUCTION: Estuaries have received considerable attention from biologists in southern Africa in the past thirty years. Professor J.H. Day and the Zoology Department of the University of Cape Town have undertaken ecological surveys of a large number of estuaries of a variety of types, laying the important groundwork for more detailed studies of single species or problems. Their studies showed that the fish populations of southern African estuaries consist mainly of marine species. Why and when these species enter or leave the estuaries and whether they grow or breed in them were not established. The only relatively detailed study of a fish in southern African estuaries was that of Talbot (1955) who investigated aspects of the growth, feeding and reproduction of Rhabdosargus globiceps (Cuvier). No quantitative information has been published on any of the fish species, perhaps due to the difficulty of obtaining such data; results such as population estimates, mortality rates and growth rates are particularly unreliable when the area being investigated is in direct contact with the sea. Studies relating to even a single species of fish are hampered by immigration and emigration between estuary and sea, which make the population continuously variable. The larger estuaries are also difficult to sample adequately, especially with regard to netting, except perhaps on a very large scale using expensive commercial equipment. Along the southern African coast many of the smaller estuaries with a limited catchment area are cut off from the sea for most of the year due to erratic rainfall and longshore drift of sand. These closed or 'blind' estuaries of south eastern Africa, of which there are at least thirty in the eastern Cape Province, provide excellent areas for studying estuarine fish populations which enter when the estuary is open to the sea, but become isolated once it closes. These fish which become cut off in closed estuaries are subject to a new series of conditions. They are exposed to the wider temperature and salinity fluctuations of an estuary and they are forced to utilise the food resources of the estuary. Additionally they may be subjected to predation from piscivorous birds, and those predatory fish which are also cut off in the estuary. These factors will affect the size, mortality, and growth rates of a fish population. Since the fish are isolated no recruitment from the sea can take place, and any increase in numbers would have to come from breeding within the estuary. It is inevitable that the most numerous species should receive attention first. Rhabdosargus holubi (Steindachner) (Synonomy : Sargus holubi Stndr, Austrosparus tricuspidens Smith, Rhabdosargus tricuspidens (Smith))(Plate 1) is one of the most abundant fish in the estuaries of the eastern Cape Province. According to Smith (1965) it is endemic to southern Africa, occurring from the Cape to Zululand, being most common between Mossel Bay and East London. It is largely replaced by Rhabdosargus sarba (Forskal) in the north of its range and by Rhabdosargus globiceps (Cuvier) in the south. Commonly called the 'flatty' or silver bream it is considered only as being of nuisance value by fishermen, seldom exceeding 30 cm in length. In this study the ecology of R.holubi was examined in relation to the closed West Kleinemond estuary which is a small 'blind' estuary typical of those found along the eastern Cape coast. The growth, mortality and population size of R.holubi in this estuary were investigated and linked where possible with predation and detailed studies into the tolerances, food, and feeding of the species. It was not known at the commencement of the study whether breeding could occur in estuaries, although Smith (1965) stated that R.holubi does breed in estuaries. During the course of the sampling programme in the West Kleinemond estuary, measurements of the growth and population structure of two other species of fish were recorded for comparison with R.holubi: the sparid Lithognathus lithognathus (Cuvier) (White Steenbras) and the piscivorous carangid Hypacanthas amia (L.) (Leervis or garrick). Laboratory studies on R.holubi were possible due to the fact that large numbers of this species could be caught in eastern Cape estuaries and transported to Grahamstown, where they could be maintained in captivity for up to four months in recirculating seawater aquaria. During the course of the study over 2000 fish were kept in captivity at different times for a variety of experiments. Another 2500 were preserved for gut analyses and lipid determinations, while over 5000 were captured, examined and released in the field.
- Full Text:
- Date Issued: 1974
The economic structure of the Cape Midlands and Karroo Region : a sectoral and spatial survey
- Authors: Blumenfeld, Jesmond P
- Date: 1974
- Subjects: South Africa -- Economic conditions -- 1961-1991 , Regional planning -- South Africa -- Cape Province
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:1066 , http://hdl.handle.net/10962/d1007660 , South Africa -- Economic conditions -- 1961-1991 , Regional planning -- South Africa -- Cape Province
- Description: [The] region, as defined, excludes not only these metropolitan areas themselves but also the inner peripheries of their hinterlands. Thus, virtually all areas within regular (i. e. daily) commuting distance of the metropolitan centres, and all areas into which urban development in the latter might 'spill over' in the foreseeable future are excluded. In the case of Metropolitan Port Elizabeth, these exclusions are reflected in the roughly 'crescent-shaped' southern boundary of the region. The situation of the region can further be described in terms of its major physiographic features which reveal a number of factors which are also of importance for understanding and analysing the economy of the area. Intro., p. 1.
- Full Text:
- Date Issued: 1974
- Authors: Blumenfeld, Jesmond P
- Date: 1974
- Subjects: South Africa -- Economic conditions -- 1961-1991 , Regional planning -- South Africa -- Cape Province
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:1066 , http://hdl.handle.net/10962/d1007660 , South Africa -- Economic conditions -- 1961-1991 , Regional planning -- South Africa -- Cape Province
- Description: [The] region, as defined, excludes not only these metropolitan areas themselves but also the inner peripheries of their hinterlands. Thus, virtually all areas within regular (i. e. daily) commuting distance of the metropolitan centres, and all areas into which urban development in the latter might 'spill over' in the foreseeable future are excluded. In the case of Metropolitan Port Elizabeth, these exclusions are reflected in the roughly 'crescent-shaped' southern boundary of the region. The situation of the region can further be described in terms of its major physiographic features which reveal a number of factors which are also of importance for understanding and analysing the economy of the area. Intro., p. 1.
- Full Text:
- Date Issued: 1974
The Grahamstown Fine Art Association
- Authors: Cook, J C W
- Date: 1974
- Subjects: Grahamstown Fine Art Association Rhodes University -- History Artists -- South Africa Painters -- South Africa Rhodes University -- School of Art
- Language: English
- Type: Thesis , Masters , MFA
- Identifier: vital:2476 , http://hdl.handle.net/10962/d1010601
- Description: When he opened the 24th annual exhibition of students' work on the 1st July, 1927, Professor F.W. Armstrong gave the following account of the beginnings of the Grahamstown School of Art: ... The appointment of a master was the responsibility of Sir Langham Dale, the Superintendent General of Education in the Cape Colony. His choice for the first art master of the Grahamstown School of Art was Mr.W. H. Simpson. Simpson had studied at the South Kensington Museum then at the Royal Academy. During the 1870's he had exhibited in the Royal Academy, at other exhibitions in London, and in the provinces. Intro. p. 1.
- Full Text:
- Date Issued: 1974
- Authors: Cook, J C W
- Date: 1974
- Subjects: Grahamstown Fine Art Association Rhodes University -- History Artists -- South Africa Painters -- South Africa Rhodes University -- School of Art
- Language: English
- Type: Thesis , Masters , MFA
- Identifier: vital:2476 , http://hdl.handle.net/10962/d1010601
- Description: When he opened the 24th annual exhibition of students' work on the 1st July, 1927, Professor F.W. Armstrong gave the following account of the beginnings of the Grahamstown School of Art: ... The appointment of a master was the responsibility of Sir Langham Dale, the Superintendent General of Education in the Cape Colony. His choice for the first art master of the Grahamstown School of Art was Mr.W. H. Simpson. Simpson had studied at the South Kensington Museum then at the Royal Academy. During the 1870's he had exhibited in the Royal Academy, at other exhibitions in London, and in the provinces. Intro. p. 1.
- Full Text:
- Date Issued: 1974
The musical life of Henry Hare Dugmore, 1820 settler
- Authors: Henderson, Jenifer M
- Date: 1974
- Subjects: Dugmore, H H (Henry H), 1810-1897
- Language: English
- Type: Thesis , Masters , MMus
- Identifier: vital:2682 , http://hdl.handle.net/10962/d1012262
- Description: Henry Hare Dugmore, the eldest son of Isaac and Maria, was destined to play his part in the dramatic future of his adopted country; not only to help as an artisan and a farmer, but to build in the spiritual field as an influential missionary and in the academic field as a most capable lecturer; most important of all, in the Artistic field as a Poet and a Musician.
- Full Text:
- Date Issued: 1974
- Authors: Henderson, Jenifer M
- Date: 1974
- Subjects: Dugmore, H H (Henry H), 1810-1897
- Language: English
- Type: Thesis , Masters , MMus
- Identifier: vital:2682 , http://hdl.handle.net/10962/d1012262
- Description: Henry Hare Dugmore, the eldest son of Isaac and Maria, was destined to play his part in the dramatic future of his adopted country; not only to help as an artisan and a farmer, but to build in the spiritual field as an influential missionary and in the academic field as a most capable lecturer; most important of all, in the Artistic field as a Poet and a Musician.
- Full Text:
- Date Issued: 1974
The place of man and nature in the shorter poems of William Wordsworth, 1793-1806
- Authors: Mirkin, Barry
- Date: 1974
- Subjects: Wordsworth, William, 1770-1850 -- Criticism and interpretation
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2285 , http://hdl.handle.net/10962/d1007656 , Wordsworth, William, 1770-1850 -- Criticism and interpretation
- Description: Introduction: This present essay is an analysis of the place of man and nature in [Wordsworth's] poetry ... I have been concerned essentially with trying to discover how Wordsworth used his two most prominent poetic subjects. I have attempted to trace Wordsworth's development from the poet of nature, to the poet of man, and finally to the poet of man and nature. What I have hoped would emerge from this essay is an understanding of Wordsworth's relationship with nature and his attitude to it in the poems. I have attempted to stress that man and humanity were not always important to Wordsworth as a poet, and that their importance does not eventually equal that of nature. For by 1807 man, the mind of man and humanity in general are very much more important and much more vital as poetic subjects than is nature. I have tried to show that Wordsworth was at different times a poet of landscape descriptions, a poet interested only in man and humanity, and finally a poet interested in man within nature.
- Full Text:
- Date Issued: 1974
- Authors: Mirkin, Barry
- Date: 1974
- Subjects: Wordsworth, William, 1770-1850 -- Criticism and interpretation
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2285 , http://hdl.handle.net/10962/d1007656 , Wordsworth, William, 1770-1850 -- Criticism and interpretation
- Description: Introduction: This present essay is an analysis of the place of man and nature in [Wordsworth's] poetry ... I have been concerned essentially with trying to discover how Wordsworth used his two most prominent poetic subjects. I have attempted to trace Wordsworth's development from the poet of nature, to the poet of man, and finally to the poet of man and nature. What I have hoped would emerge from this essay is an understanding of Wordsworth's relationship with nature and his attitude to it in the poems. I have attempted to stress that man and humanity were not always important to Wordsworth as a poet, and that their importance does not eventually equal that of nature. For by 1807 man, the mind of man and humanity in general are very much more important and much more vital as poetic subjects than is nature. I have tried to show that Wordsworth was at different times a poet of landscape descriptions, a poet interested only in man and humanity, and finally a poet interested in man within nature.
- Full Text:
- Date Issued: 1974
To aunt Mary - love Dorothy, February 1974
- Date: 1974
- Subjects: Butler, Guy, 1918-2001 -- Photographs Butler, Dorothy, 1916- -- Photographs Butler family -- Photographs
- Type: Image
- Identifier: http://hdl.handle.net/10962/41364 , vital:25082 , This image is held at the Cory Library for Humanities Research at Rhodes University. For further information contact cory@ru.ac.za. The digitisation of this image was made possible through a generous grant received from the Andrew W. Mellon Foundation 2014-2017. , PIC/M 4943/9.13
- Full Text: false
- Date Issued: 1974
- Date: 1974
- Subjects: Butler, Guy, 1918-2001 -- Photographs Butler, Dorothy, 1916- -- Photographs Butler family -- Photographs
- Type: Image
- Identifier: http://hdl.handle.net/10962/41364 , vital:25082 , This image is held at the Cory Library for Humanities Research at Rhodes University. For further information contact cory@ru.ac.za. The digitisation of this image was made possible through a generous grant received from the Andrew W. Mellon Foundation 2014-2017. , PIC/M 4943/9.13
- Full Text: false
- Date Issued: 1974
Towards explanation in African linguistics : inaugural lecture delivered at Rhodes University
- Authors: Fivaz, Derek
- Date: 1974
- Subjects: Rhodes University -- History , African languages -- Study and teaching , Linguistics -- Study and teaching -- South Africa
- Language: English
- Type: Text
- Identifier: vital:624 , http://hdl.handle.net/10962/d1020693 , ISBN 0949980536
- Description: Inaugural lecture delivered at Rhodes University , Rhodes University Libraries (Digitisation)
- Full Text:
- Date Issued: 1974
- Authors: Fivaz, Derek
- Date: 1974
- Subjects: Rhodes University -- History , African languages -- Study and teaching , Linguistics -- Study and teaching -- South Africa
- Language: English
- Type: Text
- Identifier: vital:624 , http://hdl.handle.net/10962/d1020693 , ISBN 0949980536
- Description: Inaugural lecture delivered at Rhodes University , Rhodes University Libraries (Digitisation)
- Full Text:
- Date Issued: 1974
The ability of four species of Southern African cichlid fishes to enter deep water
- Authors: Caulton, Mark S
- Date: 1973
- Subjects: Cichlids -- Africa, Southern , Tilapia
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5840 , http://hdl.handle.net/10962/d1010429 , Cichlids -- Africa, Southern , Tilapia
- Description: Using an experimental pressure chamber the rates of descent and the maximum depths of buoyancy equilibrium of some cichlid fishes were tested. Tilapia mossambica juveniles could descend to depths greater than 30 metres very rapidly. At 22°C small sub adult male fish (length ± 160 mm) could descend to a maximum buoyancy depth of 20 metres, small sub adult females to 13 metres while large adults (length ± 200 mm) of both sexes could descend to 11 metres. The fish generally take 4 to 5 days to reach their maximum equilibration depth. At 30°C mature adult male and female T.mossambica increased their maximum equilibration depth to 20 metres and at 15°C showed a decrease to a maximum depth of 6.7 metres. Temperature affects the rates of descent in a similar manner. T.rendalli can descend to 7.5 metres at 22°C. T.sparmanii can descend to 15 metres at 22°C. Hemihaplochromis philander fry and young juveniles are not affected by pressure. Adult males can descend to 16 metres at 22°C and 20 metres at 30°C. Adult females can descend to 26 metres at 22°C and 27 metres at 30°C. In T.mossambica oxygen appears to be the only gas secreted into the swimbladder to compensate for buoyancy loss. The haemoglobin of T.mossambica showed a marked Bohr and Root effect. Increased rates of descent with increased temperature are believed to be due to increased O₂ uptake, heart output etc. rather than as a direct effect of blood chemistry. The swimbladder wall of T.mossambica is extremely thin (2.8 ∕∪ m) and consequently a large amount of gas is lost through passive diffusion. Diffusion is not affected by temperature, consequently the increased secretory rates at higher temperatures are not balanced by a proportionately higher diffusion loss, thus enabling the fish to maintain a deeper buoyancy equilibrium at higher temperatures. Summary, p. 62-63.
- Full Text:
- Date Issued: 1973
- Authors: Caulton, Mark S
- Date: 1973
- Subjects: Cichlids -- Africa, Southern , Tilapia
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5840 , http://hdl.handle.net/10962/d1010429 , Cichlids -- Africa, Southern , Tilapia
- Description: Using an experimental pressure chamber the rates of descent and the maximum depths of buoyancy equilibrium of some cichlid fishes were tested. Tilapia mossambica juveniles could descend to depths greater than 30 metres very rapidly. At 22°C small sub adult male fish (length ± 160 mm) could descend to a maximum buoyancy depth of 20 metres, small sub adult females to 13 metres while large adults (length ± 200 mm) of both sexes could descend to 11 metres. The fish generally take 4 to 5 days to reach their maximum equilibration depth. At 30°C mature adult male and female T.mossambica increased their maximum equilibration depth to 20 metres and at 15°C showed a decrease to a maximum depth of 6.7 metres. Temperature affects the rates of descent in a similar manner. T.rendalli can descend to 7.5 metres at 22°C. T.sparmanii can descend to 15 metres at 22°C. Hemihaplochromis philander fry and young juveniles are not affected by pressure. Adult males can descend to 16 metres at 22°C and 20 metres at 30°C. Adult females can descend to 26 metres at 22°C and 27 metres at 30°C. In T.mossambica oxygen appears to be the only gas secreted into the swimbladder to compensate for buoyancy loss. The haemoglobin of T.mossambica showed a marked Bohr and Root effect. Increased rates of descent with increased temperature are believed to be due to increased O₂ uptake, heart output etc. rather than as a direct effect of blood chemistry. The swimbladder wall of T.mossambica is extremely thin (2.8 ∕∪ m) and consequently a large amount of gas is lost through passive diffusion. Diffusion is not affected by temperature, consequently the increased secretory rates at higher temperatures are not balanced by a proportionately higher diffusion loss, thus enabling the fish to maintain a deeper buoyancy equilibrium at higher temperatures. Summary, p. 62-63.
- Full Text:
- Date Issued: 1973