Aspects of the geochemistry of the Karroo dolerites and basalts of the north-eastern Cape
- Authors: Robey, Julian van Aardt
- Date: 1976
- Subjects: Diabase -- South Africa -- Cape of Good Hope , Basalt -- South Africa -- Cape of Good Hope , Geochemistry -- South Africa -- Cape of Good Hope
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5060 , http://hdl.handle.net/10962/d1013070
- Description: The Birds River Gabbro Complex is intruded into sediments of the Karroo Stormberg Group in the area SW of Dordrecht in the northeastern Cape. A geochemical investigation, restricted to the igneous rock suite, gabbro-ferrogabbro-ferrotholeiite, presents new major-element data as well as data for twelve trace elements - Ba, Sr, Rb, Zr, Y, Nb , Zn, Cu, Ni, Co, V and Cr. The strong degree of differentiation of Kokstad-type tholeiitic magma in the Birds River intrusion, as noted by previous investigators, is revealed in variation diagrams in which data are plotted against a simple index of fractionation. Later differentiates are strongly enriched in Si, Ti, Fe, Na, K, P, Ba, Rb, Zr, Y, Nb, Zn and Cu but depleted in Mg, Ca, AI, Ni, Co and Cr. Extreme differentiation resulted in a strong depletion of Ti, Fe, P, Cu and V in the most highly evolved ferrotholeiites. Field evidence suggests the initial emplacement of strongly fractionated magmatic residua derived from fractional crystallization processes in a magma chamber at depth during cauldron subsidence of a mass of sediments within an annular fracture. These porphyritic, in part glassy, ferrotholeiites are enriched in Si, Na, K, Ba, Zr, Rb, Y, Nb and Zn and were engulfed by a later episode of renewed hypabyssal intrusive activity from the original source area. The younger gabbro was emplaced in a series of closely-spaced heaves or pulses of relatively undifferentiated Kokstad-type magma. The gabbro differentiated in place to form ferrogabbros which chemically closely approximate ferrotholeiite compositions. toidal facies. Residual liquids crystallized as a pegmatoidal facies. A simple fractional crystallization path, modelled on the assumption that the gabbro and ferrotholeiite form a continuous series, indicates that the least evolved ferrotholeiite can be derived from the initial gabbro composition by the fractionation of major amounts of plagioclase and pyroxene but lesser amounts of olivine. Crystallization and removal of magnetite and other Fe-oxides were relatively more important during the later stages of differentiation. The variation of major- and trace-elements in tholeiitic Karroo magma under conditions of strong differentiation at Birds River serves as a framework for the regional study of the geochemistry of other Karroo dolerites and volcanics of the north-eastern Cape. New geochemical data are presented for a sample of thirty chilled and coarse-grained Karroo dolerites collected throughout the north eastern Cape. For the most part, the chilled dolerites are relatively undifferentiated and the average composition differs only slightly from that determined by Walker and Poldervaart (1949). Variation diagrams reveal the steady increase in Si, Al, Ca, Na, K and P and the residual trace elements Ba, Zr, Rb, Y, Nb and Zn with increasing differentiation of the dolerites from more basic types. The concentrations of K, Ba and Rb are highly variable in some Karroo dolerites while new data suggest that Nb levels in the dolerites are low, being generally less than 10 ppm. The strong variation of the K-related elements (K, Ba and Rb) as well as the large ranges determined for certain inter-element ratios, such as K/Rb, Zr/Nb and K/Zr in the chilled Karroo dolerites, suggest that factors other than fractional crystallization processes need to be considered to account for individual variations. Little correlation exists between petrographic type as defined by Walker and Poldervaart (1949) and geochemical character. New geochemical data are also presented for ten Karroo basaltic lavas from the lowermost horizons of the lava sequence exposed in the Barkly East area. Major- and trace-element data indicate that these earliest Karroo extrusives are on average enriched in Si and Rb but depleted in Co and Ni when compared with the averaged chilled Karroo dolerite. Compared with basalts from Lesotho, the Barkly East basalts are enriched in Si but depleted in Ni and possibly Nb, Cu and V. The andesite is markedly enriched in Si, Na, K, Ba, Sr, Rb, Zr and Nb but depleted in Mg, Ca, V, Ni , Cu, Co and Cr. The subdued rate of Ni depletion and the absence of olivine as a major phenocryst phase in the series basalt to andesite, in the Barkly East area, suggests that differentiation trends may be controlled by the fractional crystallization of orthopyroxene and plagioclase, the two common phenocrysts present in these volcanics. The strong depletion of V and Cu in the andesite may indicate some magnetite removal during fractional crystallization.
- Full Text:
- Date Issued: 1976
- Authors: Robey, Julian van Aardt
- Date: 1976
- Subjects: Diabase -- South Africa -- Cape of Good Hope , Basalt -- South Africa -- Cape of Good Hope , Geochemistry -- South Africa -- Cape of Good Hope
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5060 , http://hdl.handle.net/10962/d1013070
- Description: The Birds River Gabbro Complex is intruded into sediments of the Karroo Stormberg Group in the area SW of Dordrecht in the northeastern Cape. A geochemical investigation, restricted to the igneous rock suite, gabbro-ferrogabbro-ferrotholeiite, presents new major-element data as well as data for twelve trace elements - Ba, Sr, Rb, Zr, Y, Nb , Zn, Cu, Ni, Co, V and Cr. The strong degree of differentiation of Kokstad-type tholeiitic magma in the Birds River intrusion, as noted by previous investigators, is revealed in variation diagrams in which data are plotted against a simple index of fractionation. Later differentiates are strongly enriched in Si, Ti, Fe, Na, K, P, Ba, Rb, Zr, Y, Nb, Zn and Cu but depleted in Mg, Ca, AI, Ni, Co and Cr. Extreme differentiation resulted in a strong depletion of Ti, Fe, P, Cu and V in the most highly evolved ferrotholeiites. Field evidence suggests the initial emplacement of strongly fractionated magmatic residua derived from fractional crystallization processes in a magma chamber at depth during cauldron subsidence of a mass of sediments within an annular fracture. These porphyritic, in part glassy, ferrotholeiites are enriched in Si, Na, K, Ba, Zr, Rb, Y, Nb and Zn and were engulfed by a later episode of renewed hypabyssal intrusive activity from the original source area. The younger gabbro was emplaced in a series of closely-spaced heaves or pulses of relatively undifferentiated Kokstad-type magma. The gabbro differentiated in place to form ferrogabbros which chemically closely approximate ferrotholeiite compositions. toidal facies. Residual liquids crystallized as a pegmatoidal facies. A simple fractional crystallization path, modelled on the assumption that the gabbro and ferrotholeiite form a continuous series, indicates that the least evolved ferrotholeiite can be derived from the initial gabbro composition by the fractionation of major amounts of plagioclase and pyroxene but lesser amounts of olivine. Crystallization and removal of magnetite and other Fe-oxides were relatively more important during the later stages of differentiation. The variation of major- and trace-elements in tholeiitic Karroo magma under conditions of strong differentiation at Birds River serves as a framework for the regional study of the geochemistry of other Karroo dolerites and volcanics of the north-eastern Cape. New geochemical data are presented for a sample of thirty chilled and coarse-grained Karroo dolerites collected throughout the north eastern Cape. For the most part, the chilled dolerites are relatively undifferentiated and the average composition differs only slightly from that determined by Walker and Poldervaart (1949). Variation diagrams reveal the steady increase in Si, Al, Ca, Na, K and P and the residual trace elements Ba, Zr, Rb, Y, Nb and Zn with increasing differentiation of the dolerites from more basic types. The concentrations of K, Ba and Rb are highly variable in some Karroo dolerites while new data suggest that Nb levels in the dolerites are low, being generally less than 10 ppm. The strong variation of the K-related elements (K, Ba and Rb) as well as the large ranges determined for certain inter-element ratios, such as K/Rb, Zr/Nb and K/Zr in the chilled Karroo dolerites, suggest that factors other than fractional crystallization processes need to be considered to account for individual variations. Little correlation exists between petrographic type as defined by Walker and Poldervaart (1949) and geochemical character. New geochemical data are also presented for ten Karroo basaltic lavas from the lowermost horizons of the lava sequence exposed in the Barkly East area. Major- and trace-element data indicate that these earliest Karroo extrusives are on average enriched in Si and Rb but depleted in Co and Ni when compared with the averaged chilled Karroo dolerite. Compared with basalts from Lesotho, the Barkly East basalts are enriched in Si but depleted in Ni and possibly Nb, Cu and V. The andesite is markedly enriched in Si, Na, K, Ba, Sr, Rb, Zr and Nb but depleted in Mg, Ca, V, Ni , Cu, Co and Cr. The subdued rate of Ni depletion and the absence of olivine as a major phenocryst phase in the series basalt to andesite, in the Barkly East area, suggests that differentiation trends may be controlled by the fractional crystallization of orthopyroxene and plagioclase, the two common phenocrysts present in these volcanics. The strong depletion of V and Cu in the andesite may indicate some magnetite removal during fractional crystallization.
- Full Text:
- Date Issued: 1976
First Angoulême Festival
- Unknown
- Authors: Unknown
- Subjects: McGregor, Chris--1936-1990 , Jazz
- Language: French
- Type: Text
- Identifier: vital:13770 , http://hdl.handle.net/10962/d1012787
- Description: Original program for the first music festival of Angoulême, France.
- Full Text:
- Authors: Unknown
- Subjects: McGregor, Chris--1936-1990 , Jazz
- Language: French
- Type: Text
- Identifier: vital:13770 , http://hdl.handle.net/10962/d1012787
- Description: Original program for the first music festival of Angoulême, France.
- Full Text:
Jazz Informations
- Unknown
- Authors: Unknown
- Subjects: McGregor, Chris--1936-1990 , Brotherhood of Breath (Musical group) , Blue Notes (Musical group : South Africa) , Feza, Mongezi
- Language: English
- Type: Article
- Identifier: vital:13713 , http://hdl.handle.net/10962/d1012725
- Description: Photocopied article from Jazz magazine about Mongezi Feza's death. There is a photo of Mongezi Feza with this article.
- Full Text:
- Authors: Unknown
- Subjects: McGregor, Chris--1936-1990 , Brotherhood of Breath (Musical group) , Blue Notes (Musical group : South Africa) , Feza, Mongezi
- Language: English
- Type: Article
- Identifier: vital:13713 , http://hdl.handle.net/10962/d1012725
- Description: Photocopied article from Jazz magazine about Mongezi Feza's death. There is a photo of Mongezi Feza with this article.
- Full Text:
Brotherhood of Breath at QEH
- Authors: Lake, Steve
- Subjects: McGregor, Chris--1936-1990 , Brotherhood of Breath (Musical group) , Jazz , Jazz musicians
- Language: English
- Type: Article
- Identifier: vital:13556 , http://hdl.handle.net/10962/d1006440 , McGregor, Chris--1936-1990 , Brotherhood of Breath (Musical group) , Jazz , Jazz musicians
- Description: Photocopied article about a concert at the Queen Elisabeth Hall (QEH), England, by Chris McGregor's Brotherhood of Breath.
- Full Text:
- Authors: Lake, Steve
- Subjects: McGregor, Chris--1936-1990 , Brotherhood of Breath (Musical group) , Jazz , Jazz musicians
- Language: English
- Type: Article
- Identifier: vital:13556 , http://hdl.handle.net/10962/d1006440 , McGregor, Chris--1936-1990 , Brotherhood of Breath (Musical group) , Jazz , Jazz musicians
- Description: Photocopied article about a concert at the Queen Elisabeth Hall (QEH), England, by Chris McGregor's Brotherhood of Breath.
- Full Text:
Self-esteem of coloured and white scholars and students in South Africa
- Authors: Momberg, Allan
- Date: 1976
- Subjects: Self-esteem in children , Self-esteem -- Cross-cultural studies
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3217 , http://hdl.handle.net/10962/d1012876
- Description: A measure of the self-esteem of 426 subjects was obtained by means of the Coopersmith Self-Esteem Inventory. The sample comprised two Afrikaans, two Coloured and two English groups. Each of the above three groups was made up of pupils and students, (i. e. there were six separate sample groups). The major purpose of this study was to ascertain whether or not the Coloureds could be said to differ meaningfully from their White counterparts with regard to their general level of self-esteem. A secondary objective was to investigate the possibility of the Afrikaans and English groups differing in self-esteem. No significant differences were found to exist between any of the three student sample groups. The ranking of the mean self-esteem scores of these groups was: Afrikaans (highest), Coloured, English (lowest). The only groups that differed significantly from one another at the pupil level were the Afrikaans and the Coloureds. Their ranking was: Afrikaans (highest), English, Coloured (lowest). The prediction arising from the hypothesis of this study was that the Coloureds do not necessarily differ from Whites in their general level of self-esteem. This view is held because factors similar to those which are believed to have facilitated the rise in the self-esteem of the American Negroes are now operating in South Africa. It was concluded that this prediction was upheld.
- Full Text:
- Date Issued: 1976
- Authors: Momberg, Allan
- Date: 1976
- Subjects: Self-esteem in children , Self-esteem -- Cross-cultural studies
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3217 , http://hdl.handle.net/10962/d1012876
- Description: A measure of the self-esteem of 426 subjects was obtained by means of the Coopersmith Self-Esteem Inventory. The sample comprised two Afrikaans, two Coloured and two English groups. Each of the above three groups was made up of pupils and students, (i. e. there were six separate sample groups). The major purpose of this study was to ascertain whether or not the Coloureds could be said to differ meaningfully from their White counterparts with regard to their general level of self-esteem. A secondary objective was to investigate the possibility of the Afrikaans and English groups differing in self-esteem. No significant differences were found to exist between any of the three student sample groups. The ranking of the mean self-esteem scores of these groups was: Afrikaans (highest), Coloured, English (lowest). The only groups that differed significantly from one another at the pupil level were the Afrikaans and the Coloureds. Their ranking was: Afrikaans (highest), English, Coloured (lowest). The prediction arising from the hypothesis of this study was that the Coloureds do not necessarily differ from Whites in their general level of self-esteem. This view is held because factors similar to those which are believed to have facilitated the rise in the self-esteem of the American Negroes are now operating in South Africa. It was concluded that this prediction was upheld.
- Full Text:
- Date Issued: 1976
Some problems of dialect lexicography with particular reference to the preparation of a draft of an illustrative, experientially categorised Dictionary of South African English
- Authors: Branford, Jean
- Date: 1976
- Subjects: English language -- Provincialisms -- South Africa -- Dictionaries English language -- South Africa English language -- Lexicography -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3626 , http://hdl.handle.net/10962/d1009689
- Description: This dissertation consists in essence of an experiment and a commentary upon it. The text which constitutes Part II is a lexicographical experiment incorporating some features and treatments not usual in lexicography, and Part I consists of a discussion of the problems encountered, principles applied and procedures followed. Neither the matter nor the manner of the experiment, however, lends itself in the present state of our knowledge to the fully impersonal objectivity that is often claimed for the experiments in the physical sciences. At the same time every effort has been made to establish an unbiased record of the data and to maintain a certain methodological consistency. The main experimental feature of Part II is that it is an attempt to combine an orthodox, alphabetical dictionary with an experiential categorisation of the vocabulary, without repeating the entire data for each type of treatment. This has been done by means of a series of numbered, classified word-lists with a limited subject index as a guide to their use. The entries themselves, instead of being repeated in the order of their classification, are numbered according to the category or categories to which the word defined belongs. It can then, by means of its number(s), be found in its own lexical or experiential set (or sets) in the categorised section. This part of the work might be better described as lexicology rather than lexicography but does, I think, prove itself to be a useful adjunct to the A - Z lexicon proper. Apart from the detailed categorisation system the text contains three features not normally included in dictionaries of small compass: illustrative quotations, etymologies and a number of tentative parallels between South African and other varieties of English by means of cross-references to items of similar or related meaning or form in the English of Australia, Canada, the U.S.A., Hong Kong, Anglo-India and other 'overseas' English speech communities. Introduction, p. 1.
- Full Text:
- Date Issued: 1976
- Authors: Branford, Jean
- Date: 1976
- Subjects: English language -- Provincialisms -- South Africa -- Dictionaries English language -- South Africa English language -- Lexicography -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3626 , http://hdl.handle.net/10962/d1009689
- Description: This dissertation consists in essence of an experiment and a commentary upon it. The text which constitutes Part II is a lexicographical experiment incorporating some features and treatments not usual in lexicography, and Part I consists of a discussion of the problems encountered, principles applied and procedures followed. Neither the matter nor the manner of the experiment, however, lends itself in the present state of our knowledge to the fully impersonal objectivity that is often claimed for the experiments in the physical sciences. At the same time every effort has been made to establish an unbiased record of the data and to maintain a certain methodological consistency. The main experimental feature of Part II is that it is an attempt to combine an orthodox, alphabetical dictionary with an experiential categorisation of the vocabulary, without repeating the entire data for each type of treatment. This has been done by means of a series of numbered, classified word-lists with a limited subject index as a guide to their use. The entries themselves, instead of being repeated in the order of their classification, are numbered according to the category or categories to which the word defined belongs. It can then, by means of its number(s), be found in its own lexical or experiential set (or sets) in the categorised section. This part of the work might be better described as lexicology rather than lexicography but does, I think, prove itself to be a useful adjunct to the A - Z lexicon proper. Apart from the detailed categorisation system the text contains three features not normally included in dictionaries of small compass: illustrative quotations, etymologies and a number of tentative parallels between South African and other varieties of English by means of cross-references to items of similar or related meaning or form in the English of Australia, Canada, the U.S.A., Hong Kong, Anglo-India and other 'overseas' English speech communities. Introduction, p. 1.
- Full Text:
- Date Issued: 1976
Rhodeo, Vol. 30, No. 2
- Date: 1976
- Subjects: Grahamstown -- Newspapers , Journalism, Students -- South Africa , Rhodes University -- Activate , Rhodes University -- Students , Student newspapers and periodicals -- South Africa
- Language: English
- Type: Text
- Identifier: vital:14670 , http://hdl.handle.net/10962/d1019542
- Description: Rhodeo is the Independent Student Newspaper of Rhodes University. Located in Grahamstown, Rhodeo was established in 1947, and renamed in 1994 as Activate. During apartheid Rhodeo became an active part of the struggle for freedom of expression as part of the now defunct South African Student Press Union. Currently Activate is committed to informing Rhodes University students, staff and community members about relevant issues, mainly on campus. These issues range from hard news to more creative journalism. While Activate acts as a news source, one of its main objectives it to be accessible as a training ground for student journalists. The newspaper is run entirely by the students and is published twice a term. Activate is a free newspaper which receives an annual grant from the Rhodes University Student Representative Council, however, majority of its revenue is generated through advertising.
- Full Text:
- Date Issued: 1976
- Date: 1976
- Subjects: Grahamstown -- Newspapers , Journalism, Students -- South Africa , Rhodes University -- Activate , Rhodes University -- Students , Student newspapers and periodicals -- South Africa
- Language: English
- Type: Text
- Identifier: vital:14670 , http://hdl.handle.net/10962/d1019542
- Description: Rhodeo is the Independent Student Newspaper of Rhodes University. Located in Grahamstown, Rhodeo was established in 1947, and renamed in 1994 as Activate. During apartheid Rhodeo became an active part of the struggle for freedom of expression as part of the now defunct South African Student Press Union. Currently Activate is committed to informing Rhodes University students, staff and community members about relevant issues, mainly on campus. These issues range from hard news to more creative journalism. While Activate acts as a news source, one of its main objectives it to be accessible as a training ground for student journalists. The newspaper is run entirely by the students and is published twice a term. Activate is a free newspaper which receives an annual grant from the Rhodes University Student Representative Council, however, majority of its revenue is generated through advertising.
- Full Text:
- Date Issued: 1976
Chris McGregor's Brotherhood of Breath: Our God is a consuming fire
- Unknown
- Authors: Unknown
- Subjects: McGregor, Chris--1936-1990 , Brotherhood of Breath (Musical group) , Jazz
- Language: English
- Type: Text
- Identifier: vital:13767 , http://hdl.handle.net/10962/d1012783
- Description: Original poster for March Jazz festival in London where Chris McGregor's Brotherhood of Breath is premiering "Our God is a Consuming Fire", Chris McGregor's new work, at the Queen Elizabeth Hall.
- Full Text:
- Authors: Unknown
- Subjects: McGregor, Chris--1936-1990 , Brotherhood of Breath (Musical group) , Jazz
- Language: English
- Type: Text
- Identifier: vital:13767 , http://hdl.handle.net/10962/d1012783
- Description: Original poster for March Jazz festival in London where Chris McGregor's Brotherhood of Breath is premiering "Our God is a Consuming Fire", Chris McGregor's new work, at the Queen Elizabeth Hall.
- Full Text:
The multiple image in art : a personal response
- Authors: Swift, Anthony J M
- Date: 1976
- Subjects: Art, Modern -- 20th century , Art -- Themes, motives , Art appreciation , Art, Modern -- 20th century -- Philosophy
- Language: English
- Type: Thesis , Masters , MFA
- Identifier: vital:2497 , http://hdl.handle.net/10962/d1013330
- Description: The development of this thesis is akin to that of a painting. It is subject to various influences that have evoked ideas and each idea has stimulated other ideas, thus the continuity could have gone beyond the bounds of this work. It is not so much an amalgamation of similar ideas but a development of diverse ideas which have, once composed, a common factor - the Multiple Image. Image refers to some paintings that have been made or part of them, a photograph, a film, a subject visualized in the mind or a complex reforms which is suggestive. Multiple refers to anything that relatively repeats itself, has facsimilies of itself, triptychs, polyptychs or is a conglomeration of ideas in a work of art. Intro., p. 1.
- Full Text:
- Date Issued: 1976
- Authors: Swift, Anthony J M
- Date: 1976
- Subjects: Art, Modern -- 20th century , Art -- Themes, motives , Art appreciation , Art, Modern -- 20th century -- Philosophy
- Language: English
- Type: Thesis , Masters , MFA
- Identifier: vital:2497 , http://hdl.handle.net/10962/d1013330
- Description: The development of this thesis is akin to that of a painting. It is subject to various influences that have evoked ideas and each idea has stimulated other ideas, thus the continuity could have gone beyond the bounds of this work. It is not so much an amalgamation of similar ideas but a development of diverse ideas which have, once composed, a common factor - the Multiple Image. Image refers to some paintings that have been made or part of them, a photograph, a film, a subject visualized in the mind or a complex reforms which is suggestive. Multiple refers to anything that relatively repeats itself, has facsimilies of itself, triptychs, polyptychs or is a conglomeration of ideas in a work of art. Intro., p. 1.
- Full Text:
- Date Issued: 1976
Die administratiewe funksionering van bewindsinstellings in die Ciskei met besondere verwysing na plaaslike bestuur
- Authors: Groenewald, David Marais
- Date: 1976
- Subjects: Public institutions -- Administration -- South Africa -- Ciskei , Public institutions -- Management -- South Africa -- Ciskei , Public institutions -- Government -- South Africa -- Ciskei
- Language: Afrikaans
- Type: Thesis , Masters , MA
- Identifier: vital:2877 , http://hdl.handle.net/10962/d1012099 , Public institutions -- Administration -- South Africa -- Ciskei , Public institutions -- Management -- South Africa -- Ciskei , Public institutions -- Government -- South Africa -- Ciskei
- Description: As gevolg van die ongekonsolideerde aard van die Bantoegebiede in die Ciskei is dit onmoontlik om diè gebied te begrens binne bepaalde relief kenmerke, soos bv. berge en riviere; of selfs binne administratiewe grense soos bv. magistraatsdistrikte. Intro., p. 1
- Full Text:
- Date Issued: 1976
- Authors: Groenewald, David Marais
- Date: 1976
- Subjects: Public institutions -- Administration -- South Africa -- Ciskei , Public institutions -- Management -- South Africa -- Ciskei , Public institutions -- Government -- South Africa -- Ciskei
- Language: Afrikaans
- Type: Thesis , Masters , MA
- Identifier: vital:2877 , http://hdl.handle.net/10962/d1012099 , Public institutions -- Administration -- South Africa -- Ciskei , Public institutions -- Management -- South Africa -- Ciskei , Public institutions -- Government -- South Africa -- Ciskei
- Description: As gevolg van die ongekonsolideerde aard van die Bantoegebiede in die Ciskei is dit onmoontlik om diè gebied te begrens binne bepaalde relief kenmerke, soos bv. berge en riviere; of selfs binne administratiewe grense soos bv. magistraatsdistrikte. Intro., p. 1
- Full Text:
- Date Issued: 1976
Reading the signs : inaugural address delivered at Rhodes University
- Authors: Seagrief, S C
- Date: 1976
- Subjects: Botany -- South Africa , Marine algae -- South Africa
- Language: English
- Type: Text
- Identifier: vital:667 , http://hdl.handle.net/10962/d1020736 , ISBN 0949980749
- Description: Inaugural address delivered at Rhodes University , Rhodes University Libraries (Digitisation)
- Full Text:
- Date Issued: 1976
- Authors: Seagrief, S C
- Date: 1976
- Subjects: Botany -- South Africa , Marine algae -- South Africa
- Language: English
- Type: Text
- Identifier: vital:667 , http://hdl.handle.net/10962/d1020736 , ISBN 0949980749
- Description: Inaugural address delivered at Rhodes University , Rhodes University Libraries (Digitisation)
- Full Text:
- Date Issued: 1976
The keyboard sonatas of Pietro Augusto : an investigation into their formal and stylistic apsects
- Radloff, Timothy Edward Kingswell
- Authors: Radloff, Timothy Edward Kingswell
- Date: 1976
- Subjects: Augusto, Pietro , Sonatas (Piano)
- Language: English
- Type: Thesis , Masters , MMus
- Identifier: vital:2689 , http://hdl.handle.net/10962/d1013047
- Description: This thesis supplements "The Piano Sonata of the Eighteenth Century in Germany" (Vol. 2 in the publication series "Contributions to the development of the Piano Sonata"). It does not aim at a comparative study between Pieto Augusto and his contemporaries but intends to establish the composer's individual characteristics in the light of the general development of the piano sonata during the eighteenth century.
- Full Text:
- Date Issued: 1976
- Authors: Radloff, Timothy Edward Kingswell
- Date: 1976
- Subjects: Augusto, Pietro , Sonatas (Piano)
- Language: English
- Type: Thesis , Masters , MMus
- Identifier: vital:2689 , http://hdl.handle.net/10962/d1013047
- Description: This thesis supplements "The Piano Sonata of the Eighteenth Century in Germany" (Vol. 2 in the publication series "Contributions to the development of the Piano Sonata"). It does not aim at a comparative study between Pieto Augusto and his contemporaries but intends to establish the composer's individual characteristics in the light of the general development of the piano sonata during the eighteenth century.
- Full Text:
- Date Issued: 1976
A 22 GHz radio telescope
- Authors: Mutch, Laurence Ian
- Date: 1976
- Subjects: Radio telescopes , Paraboloid , Radio astronomy
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5532 , http://hdl.handle.net/10962/d1012919
- Description: This thesis reports on the design, construction, testing and operation of the spectral line and continuum receivers built for the 22 GHz Radio Telescope. First results from 'the telescope were obtained and have been analysed to give an estimate of system efficiency. Tests have been performed on the front end and in particular on the 22 GHz mixer in order to determine the minimum detectable temperature. The Sun, Moon and major planets are sources suitable for antenna alignment and consequently a literature survey of emission at 22 GHz from elements of the Solar system has been made.
- Full Text:
- Date Issued: 1976
- Authors: Mutch, Laurence Ian
- Date: 1976
- Subjects: Radio telescopes , Paraboloid , Radio astronomy
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5532 , http://hdl.handle.net/10962/d1012919
- Description: This thesis reports on the design, construction, testing and operation of the spectral line and continuum receivers built for the 22 GHz Radio Telescope. First results from 'the telescope were obtained and have been analysed to give an estimate of system efficiency. Tests have been performed on the front end and in particular on the 22 GHz mixer in order to determine the minimum detectable temperature. The Sun, Moon and major planets are sources suitable for antenna alignment and consequently a literature survey of emission at 22 GHz from elements of the Solar system has been made.
- Full Text:
- Date Issued: 1976
Albany Rugby Football Club 1st XV, 1976
- Date: 1976
- Subjects: Rugby football -- South Africa -- Eastern Cape -- Photographs , Albany Rugby Football Club -- Photographs
- Type: still image
- Identifier: http://hdl.handle.net/10962/50789 , vital:26027 , 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 6705
- Description: Albany Rugby Football Club 1st XV 1976 , Winners of the President’s Cup, trophy cup in front, Team photograph with rugby/football players, in rugby uniform, Group photograph, Black and white photograph, Indoor photograph, Tiled floor, President holding rugby ball with “1976” on it, Club Captain, President and Coach wearing suits, Players standing have arms by sides, Players sitting have arms in lap, “Birch’s” and “George Frauenstein” written on wall in background, Back Row (left to right): R. Austin, R. Snow, C. Strydom, R. Fincham, R. Allin, D. Wicks, S. Hill, R. Moss, Seated (left to right): C. Pascoe, G. Samuel, J. A. H. Coetzee (Club Captain), B. Carlson (Captain), L. Tilney (President), L. Coetzee, G. Bezuidenhout (Coach), R. Green, N. Smuts, Front Row (left to right): P. Vermaak, P. Mathews, L. van der Merwe, C. Jones.
- Full Text: false
- Date Issued: 1976
- Date: 1976
- Subjects: Rugby football -- South Africa -- Eastern Cape -- Photographs , Albany Rugby Football Club -- Photographs
- Type: still image
- Identifier: http://hdl.handle.net/10962/50789 , vital:26027 , 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 6705
- Description: Albany Rugby Football Club 1st XV 1976 , Winners of the President’s Cup, trophy cup in front, Team photograph with rugby/football players, in rugby uniform, Group photograph, Black and white photograph, Indoor photograph, Tiled floor, President holding rugby ball with “1976” on it, Club Captain, President and Coach wearing suits, Players standing have arms by sides, Players sitting have arms in lap, “Birch’s” and “George Frauenstein” written on wall in background, Back Row (left to right): R. Austin, R. Snow, C. Strydom, R. Fincham, R. Allin, D. Wicks, S. Hill, R. Moss, Seated (left to right): C. Pascoe, G. Samuel, J. A. H. Coetzee (Club Captain), B. Carlson (Captain), L. Tilney (President), L. Coetzee, G. Bezuidenhout (Coach), R. Green, N. Smuts, Front Row (left to right): P. Vermaak, P. Mathews, L. van der Merwe, C. Jones.
- Full Text: false
- Date Issued: 1976
Mongezi Feza - Melody Maker
- Unknown
- Authors: Unknown
- Subjects: McGregor, Chris--1936-1990 , Feza, Mongezi
- Language: English
- Type: Article
- Identifier: vital:13730 , http://hdl.handle.net/10962/d1012743
- Description: Photocopied article from the newspaper Melody Maker about 2 memorial concerts as a tribute to Mongezi Feza who died in December 1975.
- Full Text:
- Authors: Unknown
- Subjects: McGregor, Chris--1936-1990 , Feza, Mongezi
- Language: English
- Type: Article
- Identifier: vital:13730 , http://hdl.handle.net/10962/d1012743
- Description: Photocopied article from the newspaper Melody Maker about 2 memorial concerts as a tribute to Mongezi Feza who died in December 1975.
- Full Text:
Rodin and his contemporaries
- Authors: Henderson, Derek Scott
- Subjects: Rodin, Auguste, 1840-1917
- Language: English
- Type: Text
- Identifier: vital:7344 , http://hdl.handle.net/10962/d1017073
- Description: Opening address at the launch of the exhibition titled Rodin and his contemporaries, ath King George VI, Art Gallery, Port Elizabeth, 1976
- Full Text:
- Authors: Henderson, Derek Scott
- Subjects: Rodin, Auguste, 1840-1917
- Language: English
- Type: Text
- Identifier: vital:7344 , http://hdl.handle.net/10962/d1017073
- Description: Opening address at the launch of the exhibition titled Rodin and his contemporaries, ath King George VI, Art Gallery, Port Elizabeth, 1976
- Full Text:
Bacterial degradation of the acaricide amitraz
- Authors: Baker, Penelope Bridget
- Date: 1976
- Subjects: Acaricides , Biodegradation , Gas chromatography , Bacteriology -- Cultures and culture media
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4099 , http://hdl.handle.net/10962/d1009498
- Description: This thesis describes dip tank field trials and laboratory investigations on the acaricide Amitraz. Amitraz is a triazapenta- diene compound which is relatively unstable in fouled dip washes. The field trials were conducted on the farm Sea View according to the "Total Replacement Method" and on the farm Sea Ways according to the "Lime Stabilization Method" of dipping. The results of these trials showed that Amitraz was stable in clean dip washes, and under conditions of high pH resulting from the addition of slaked lime to the dip wash. Using mixed bacterial populations optimum conditions for degradation of Amitraz in the laboratory were determined. Bacterial cultures degraded Amitraz most efficiently in media supplemented with yeast extract or with a high content of sterile cattle faeces. Amitraz concentrations were determined by gas chromatography. A culture. efficient at degrading Amitraz was enriched from a dip tank sludge inoculum. From this culture ten bacterial isolates were identified; nine of these were of the genus Pseudomonas and one was an Achromobacter sp. Experiments with both mixed and pure cultures demonstrated that bacterial degradation of Amitraz was by the process of co-metabolism. The existence of four degradation products was shown using thin layer chromatography. Tentative identification of two of the products was made.
- Full Text:
- Date Issued: 1976
- Authors: Baker, Penelope Bridget
- Date: 1976
- Subjects: Acaricides , Biodegradation , Gas chromatography , Bacteriology -- Cultures and culture media
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4099 , http://hdl.handle.net/10962/d1009498
- Description: This thesis describes dip tank field trials and laboratory investigations on the acaricide Amitraz. Amitraz is a triazapenta- diene compound which is relatively unstable in fouled dip washes. The field trials were conducted on the farm Sea View according to the "Total Replacement Method" and on the farm Sea Ways according to the "Lime Stabilization Method" of dipping. The results of these trials showed that Amitraz was stable in clean dip washes, and under conditions of high pH resulting from the addition of slaked lime to the dip wash. Using mixed bacterial populations optimum conditions for degradation of Amitraz in the laboratory were determined. Bacterial cultures degraded Amitraz most efficiently in media supplemented with yeast extract or with a high content of sterile cattle faeces. Amitraz concentrations were determined by gas chromatography. A culture. efficient at degrading Amitraz was enriched from a dip tank sludge inoculum. From this culture ten bacterial isolates were identified; nine of these were of the genus Pseudomonas and one was an Achromobacter sp. Experiments with both mixed and pure cultures demonstrated that bacterial degradation of Amitraz was by the process of co-metabolism. The existence of four degradation products was shown using thin layer chromatography. Tentative identification of two of the products was made.
- Full Text:
- Date Issued: 1976
Aspects of the feeding ecology of three common Sparid fish in the littoral zone at Clayton's Rocks in the Eastern Cape, with notes on their biology
- Authors: Christensen, Mikkel S
- Date: 1976
- Subjects: Sparidae -- Physiology , Sparidae -- Ecology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5356 , http://hdl.handle.net/10962/d1010476 , Sparidae -- Physiology , Sparidae -- Ecology
- Description: The feeding interrelationships of three sparid fish was studied in the littoral zone during low tide at Clayton's Rocks in the Eastern Cape. The three species appeared in the study area only when between 9 and 10 mm long (SL), and remained resident until a length of approximately 120 fmm was reached. No sexually mature specimens occurred in the study area as large adults only use the intertidal zone for feeding purposes at high tide. From first recruitment into the littoral zone at 9 mm SL until some 35 mm long, the diet of Diplodus sargus consists of harpacticoid copepods and amphipods. Ingestion of amphipods and green algae increases with increased size of fish. Chironomid larvae, cirripede nauplii and an unidentifiable planktonic larva are important food items of small juveniles ( 50 mm), while diatoms are significant in larger juveniles (25 to 80 mm) in the spring/early summer season. The gut is short and the teeth are incisiform, backed by several rows of molars which increase in size and number with age. D.cervinus was almost completely carnivorous in the size range studied. The juveniles found on harpacticoid copepods and chironomid larvae while between 10 and 20 mm long. The diet then consists mainly of the shrimp Palaemon pacificus until the fish are 50 mm long and then amphipods until 100 mm long. All fish larger than this feed prodominantly on polychaetes. The gut is short and the teeth are similar to those of Q. sargus although there are fewer molars. From its first appearance at 10 mm, Sarpa salpa feeds mainly on harpacticoid copepods until 25 mm long. Diatoms then predominate in the diet, red algae also being taken until 75 mm long. Larger size classes are herbivores, feeding almost equally on red and green algae. Corresponding changes in gut length and dentition are reported, juveniles having a short gut and conical teeth and adults a long intestine and cuspidate, incisiform teeth. Marked ecological separation was observed between the three species. Spatial, temporal , behavioural and dietary differences were found . Q. sargus has continuous recruitment of juveniles into the littoral zone, S..salpa appears between July and early September and Q.cervinus is recruited from late September to November. Competition between small juveniles is reduced by cyclic abundances of food items important to each species and the sub-adults feed on different foods. Some competition exists between large juveniles of Q. sargus and Q.cervinus, but separation is maintained as individuals of the two species feed at different levels of the water column and in different parts of the littoral zone.
- Full Text:
- Date Issued: 1976
- Authors: Christensen, Mikkel S
- Date: 1976
- Subjects: Sparidae -- Physiology , Sparidae -- Ecology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5356 , http://hdl.handle.net/10962/d1010476 , Sparidae -- Physiology , Sparidae -- Ecology
- Description: The feeding interrelationships of three sparid fish was studied in the littoral zone during low tide at Clayton's Rocks in the Eastern Cape. The three species appeared in the study area only when between 9 and 10 mm long (SL), and remained resident until a length of approximately 120 fmm was reached. No sexually mature specimens occurred in the study area as large adults only use the intertidal zone for feeding purposes at high tide. From first recruitment into the littoral zone at 9 mm SL until some 35 mm long, the diet of Diplodus sargus consists of harpacticoid copepods and amphipods. Ingestion of amphipods and green algae increases with increased size of fish. Chironomid larvae, cirripede nauplii and an unidentifiable planktonic larva are important food items of small juveniles ( 50 mm), while diatoms are significant in larger juveniles (25 to 80 mm) in the spring/early summer season. The gut is short and the teeth are incisiform, backed by several rows of molars which increase in size and number with age. D.cervinus was almost completely carnivorous in the size range studied. The juveniles found on harpacticoid copepods and chironomid larvae while between 10 and 20 mm long. The diet then consists mainly of the shrimp Palaemon pacificus until the fish are 50 mm long and then amphipods until 100 mm long. All fish larger than this feed prodominantly on polychaetes. The gut is short and the teeth are similar to those of Q. sargus although there are fewer molars. From its first appearance at 10 mm, Sarpa salpa feeds mainly on harpacticoid copepods until 25 mm long. Diatoms then predominate in the diet, red algae also being taken until 75 mm long. Larger size classes are herbivores, feeding almost equally on red and green algae. Corresponding changes in gut length and dentition are reported, juveniles having a short gut and conical teeth and adults a long intestine and cuspidate, incisiform teeth. Marked ecological separation was observed between the three species. Spatial, temporal , behavioural and dietary differences were found . Q. sargus has continuous recruitment of juveniles into the littoral zone, S..salpa appears between July and early September and Q.cervinus is recruited from late September to November. Competition between small juveniles is reduced by cyclic abundances of food items important to each species and the sub-adults feed on different foods. Some competition exists between large juveniles of Q. sargus and Q.cervinus, but separation is maintained as individuals of the two species feed at different levels of the water column and in different parts of the littoral zone.
- Full Text:
- Date Issued: 1976
Albany Rugby Football Club 1st XV, 1976
- Date: 1976
- Subjects: Rugby football -- South Africa -- Eastern Cape -- Photographs , Albany Rugby Football Club -- Photographs
- Type: still image
- Identifier: http://hdl.handle.net/10962/50799 , vital:26028 , 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 6706
- Description: Albany Rugby Football Club 1st XV 1976, Winners of the President’s Cup, trophy cup in front, Team photograph with rugby/football players, in rugby uniform, Group photograph, Black and white photograph, Indoor photograph, Tiled floor, President holding rugby ball with “1976” on it, Club Captain, President and Coach wearing suits, Players standing have arms by sides, Players sitting have arms in lap, “Birch’s” and “George Frauenstein” written on wall in background, Back Row (left to right): R. Austin, R. Snow, C. Strydom, R. Fincham, R. Allin, D. Wicks, S. Hill, R. Moss, Seated (left to right): C. Pascoe, G. Samuel, J. A. H. Coetzee (Club Captain), B. Carlson (Captain), L. Tilney (President), L. Coetzee, G. Bezuidenhout (Coach), R. Green, N. Smuts, Front Row (left to right): P. Vermaak, P. Mathews, L. van der Merwe, C. Jones.
- Full Text: false
- Date Issued: 1976
- Date: 1976
- Subjects: Rugby football -- South Africa -- Eastern Cape -- Photographs , Albany Rugby Football Club -- Photographs
- Type: still image
- Identifier: http://hdl.handle.net/10962/50799 , vital:26028 , 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 6706
- Description: Albany Rugby Football Club 1st XV 1976, Winners of the President’s Cup, trophy cup in front, Team photograph with rugby/football players, in rugby uniform, Group photograph, Black and white photograph, Indoor photograph, Tiled floor, President holding rugby ball with “1976” on it, Club Captain, President and Coach wearing suits, Players standing have arms by sides, Players sitting have arms in lap, “Birch’s” and “George Frauenstein” written on wall in background, Back Row (left to right): R. Austin, R. Snow, C. Strydom, R. Fincham, R. Allin, D. Wicks, S. Hill, R. Moss, Seated (left to right): C. Pascoe, G. Samuel, J. A. H. Coetzee (Club Captain), B. Carlson (Captain), L. Tilney (President), L. Coetzee, G. Bezuidenhout (Coach), R. Green, N. Smuts, Front Row (left to right): P. Vermaak, P. Mathews, L. van der Merwe, C. Jones.
- Full Text: false
- Date Issued: 1976
Feeding ecology of the cichlid fish Sarotherodon Mossambicus in Lake Sibaya, KwaZulu
- Authors: Bowen, Stephen H
- Date: 1977
- Subjects: Cichlids -- Ecology , Fishes -- Ecology -- South Africa -- KwaZulu-Natal -- Sibaya, Lake
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5837 , http://hdl.handle.net/10962/d1009688 , Cichlids -- Ecology , Fishes -- Ecology -- South Africa -- KwaZulu-Natal -- Sibaya, Lake
- Description: The feeding of the cichlid fish Sarotherodon mossambicus in Lake Sibaya, KwaZulu, was studied in relation to various biotic and abiotic features of the l ake environment from January, 1973 to July, 1975. The primary goal of the study was to determine the cause of stunting and poor condition of adults in this population. Juvenile and adult S. mossambicus feed on a mixture of detritus, bacteria and diatoms that occurs as a flocculent layer on sand substrates throughout the lake. Concentrated gastric acid, commonly at pH values of 1.5 and lower, lyses diatoms and bacteria which are subsequently digested in the intestine. This is the first report of digestion of bacteria by a fish, and the nutritional significance of the finding is discussed. Juveniles feed predominantly on shallow sand terraces found along the margin of much of the lake, while adults usually feed in offshore waters at depths of 3 m and greater. Benthic floc from feeding areas of juveniles and adults have similar concentrations of organic matter, total carbohydrate, soluble carbohydrate and calories, but differ markedly in respect to diatom and protein concentration. Diatom concentrations are generally high in terrace floc but are consistently low in floc from deep water. Protein concentration of benthic floc decreases with increasing depth from 0 - 5 m. Partial correlation analysis shows that protein and diatom concentrations have no correlation independent. of their common relationship to depth, and the evidence implicates detrital bacteria as the primary source of protein in benthic floc. Probable causes of the observed distributions of diatoms and protein are discussed. The protein content of benthic floc profoundly influences its nutritional value. A comparison with available data on animal nutrition shows that the ratio of digestible protein to digestible energy in floc in the shallows is high enough that this food resource would be expected to support good growth, but the ratio for deep water floc is so low that it would be expected to result in conspicuous malnutrition. Thus, inadequate dietary protein is identified as the principal cause of stunting and poor condition of adult S· mossambicus in Lake Sibaya; It is argued that the ratio of digestible protein to digestible calories can be expected to determine the food value of particulate organic matter that includes amorphous detritus in other ecosystems. Despite stunting and poor condition of adults, S. mossambicus are abundant in Lake Sibaya. The precocious breeding of this population is discussed as an adaptation that allows it to maximize reproductive output given the limited resources available to adults. Juvenile S. mossambicus perform daily movements from deep water onto the terraces where they feed and then back into deep water. During periods of relatively low lake level when terrace waters were usually less than 1.5 m deep (1-73 to 1-74), juveniles were present on the terrace throughout daylight hours. At relatively high lake levels (7-74 to 8-75), juveniles were present on the terraces for only about five hours following sunset. Periods of heavy wave action interrupt feeding activity and result in reduced numbers of fish in terrace waters. The possible roles of predator avoidance and temperature in determination of daily feeding behavior are discussed. Daily energy assimilation by juveniles, estimated by a field technique, is approximately 115 cal per g fish dry weight.
- Full Text:
- Date Issued: 1977
- Authors: Bowen, Stephen H
- Date: 1977
- Subjects: Cichlids -- Ecology , Fishes -- Ecology -- South Africa -- KwaZulu-Natal -- Sibaya, Lake
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5837 , http://hdl.handle.net/10962/d1009688 , Cichlids -- Ecology , Fishes -- Ecology -- South Africa -- KwaZulu-Natal -- Sibaya, Lake
- Description: The feeding of the cichlid fish Sarotherodon mossambicus in Lake Sibaya, KwaZulu, was studied in relation to various biotic and abiotic features of the l ake environment from January, 1973 to July, 1975. The primary goal of the study was to determine the cause of stunting and poor condition of adults in this population. Juvenile and adult S. mossambicus feed on a mixture of detritus, bacteria and diatoms that occurs as a flocculent layer on sand substrates throughout the lake. Concentrated gastric acid, commonly at pH values of 1.5 and lower, lyses diatoms and bacteria which are subsequently digested in the intestine. This is the first report of digestion of bacteria by a fish, and the nutritional significance of the finding is discussed. Juveniles feed predominantly on shallow sand terraces found along the margin of much of the lake, while adults usually feed in offshore waters at depths of 3 m and greater. Benthic floc from feeding areas of juveniles and adults have similar concentrations of organic matter, total carbohydrate, soluble carbohydrate and calories, but differ markedly in respect to diatom and protein concentration. Diatom concentrations are generally high in terrace floc but are consistently low in floc from deep water. Protein concentration of benthic floc decreases with increasing depth from 0 - 5 m. Partial correlation analysis shows that protein and diatom concentrations have no correlation independent. of their common relationship to depth, and the evidence implicates detrital bacteria as the primary source of protein in benthic floc. Probable causes of the observed distributions of diatoms and protein are discussed. The protein content of benthic floc profoundly influences its nutritional value. A comparison with available data on animal nutrition shows that the ratio of digestible protein to digestible energy in floc in the shallows is high enough that this food resource would be expected to support good growth, but the ratio for deep water floc is so low that it would be expected to result in conspicuous malnutrition. Thus, inadequate dietary protein is identified as the principal cause of stunting and poor condition of adult S· mossambicus in Lake Sibaya; It is argued that the ratio of digestible protein to digestible calories can be expected to determine the food value of particulate organic matter that includes amorphous detritus in other ecosystems. Despite stunting and poor condition of adults, S. mossambicus are abundant in Lake Sibaya. The precocious breeding of this population is discussed as an adaptation that allows it to maximize reproductive output given the limited resources available to adults. Juvenile S. mossambicus perform daily movements from deep water onto the terraces where they feed and then back into deep water. During periods of relatively low lake level when terrace waters were usually less than 1.5 m deep (1-73 to 1-74), juveniles were present on the terrace throughout daylight hours. At relatively high lake levels (7-74 to 8-75), juveniles were present on the terraces for only about five hours following sunset. Periods of heavy wave action interrupt feeding activity and result in reduced numbers of fish in terrace waters. The possible roles of predator avoidance and temperature in determination of daily feeding behavior are discussed. Daily energy assimilation by juveniles, estimated by a field technique, is approximately 115 cal per g fish dry weight.
- Full Text:
- Date Issued: 1977