Age, growth and reproduction of largemouth bass, Micropterus salmoides, in Lake Manyame, Zimbabwe
- Beamish, C A, Booth, Anthony J, Deacon, N
- Authors: Beamish, C A , Booth, Anthony J , Deacon, N
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/446770 , vital:74559 , https://doi.org/10.1080/15627020.2005.11407310
- Description: A total of 478 largemouth bass, Micropterus salmoides (Lacépède, 1802), was sampled between September 1997 and July 2001 using hook-and-line in Lake Manyame, a water supply reservoir situated outside Harare, Zimbabwe. Male fish dominated the samples, possibly an effect of aggressive behaviour towards the sampling gear used. Ages, determined from sectioned sagittal otoliths, ranged from one to nine years with 94% of the sample being between one and four years of age. An annulus was deposited in late-winter/early spring. Female fish, despite being the largest fish sampled, were found to grow at a significantly slower rate than males. Growth was modelled with the von Bertalanffy model as L(t)=37.22(1–exp(–0.66t)) cm SL for males, and L(t) = 48.16(1–exp(–0.41t)) cm SL for females. All fish matured after one year, thereafter they spawned over a four-month period between July and October. Reproductive activity peaked in August. Largemouth bass has successfully colonized freshwater bodies in southern Africa where it has been introduced, causing significant ecological damage to the indigenous ichthyofauna. Given its ability to grow to a large size, and live to an old age and to breed successfully, further introductions should be viewed with extreme caution.
- Full Text:
- Date Issued: 2005
- Authors: Beamish, C A , Booth, Anthony J , Deacon, N
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/446770 , vital:74559 , https://doi.org/10.1080/15627020.2005.11407310
- Description: A total of 478 largemouth bass, Micropterus salmoides (Lacépède, 1802), was sampled between September 1997 and July 2001 using hook-and-line in Lake Manyame, a water supply reservoir situated outside Harare, Zimbabwe. Male fish dominated the samples, possibly an effect of aggressive behaviour towards the sampling gear used. Ages, determined from sectioned sagittal otoliths, ranged from one to nine years with 94% of the sample being between one and four years of age. An annulus was deposited in late-winter/early spring. Female fish, despite being the largest fish sampled, were found to grow at a significantly slower rate than males. Growth was modelled with the von Bertalanffy model as L(t)=37.22(1–exp(–0.66t)) cm SL for males, and L(t) = 48.16(1–exp(–0.41t)) cm SL for females. All fish matured after one year, thereafter they spawned over a four-month period between July and October. Reproductive activity peaked in August. Largemouth bass has successfully colonized freshwater bodies in southern Africa where it has been introduced, causing significant ecological damage to the indigenous ichthyofauna. Given its ability to grow to a large size, and live to an old age and to breed successfully, further introductions should be viewed with extreme caution.
- Full Text:
- Date Issued: 2005
Marine Reserves: a guide to science, design, and use
- Authors: Booth, Anthony J
- Date: 2005
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124965 , vital:35714 , https://doi.10.2989/16085910509503862
- Description: With the considerable pressures that are being placed on our marine resources, there is an urgent need to find alternative strategies to ensure their long-term sustainability. One measure that has been proposed, and which is rapidly gaining popularity, is the designation of Marine Protected Area (MPA). These are demarcated areas that prohibit (or at least restrict) consumptive or extractive uses, such that human interferences and impacts are minimised. In this edited collection of papers, most of which have been written or co-written by the authors themselves, Sobel and Dahlgren have presented an excellent synopsis of the rationale behind, and the scientific basis underpinning, the use of marine reserves as a management tool. In addition, they have devoted half the book to the provision of case studies.
- Full Text:
- Date Issued: 2005
- Authors: Booth, Anthony J
- Date: 2005
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124965 , vital:35714 , https://doi.10.2989/16085910509503862
- Description: With the considerable pressures that are being placed on our marine resources, there is an urgent need to find alternative strategies to ensure their long-term sustainability. One measure that has been proposed, and which is rapidly gaining popularity, is the designation of Marine Protected Area (MPA). These are demarcated areas that prohibit (or at least restrict) consumptive or extractive uses, such that human interferences and impacts are minimised. In this edited collection of papers, most of which have been written or co-written by the authors themselves, Sobel and Dahlgren have presented an excellent synopsis of the rationale behind, and the scientific basis underpinning, the use of marine reserves as a management tool. In addition, they have devoted half the book to the provision of case studies.
- Full Text:
- Date Issued: 2005
Reproductive biology of ningu, Labeo victorianus (pisces: cyprinidae), in the kagera and Sio rivers, Uganda
- Rutaisire, Justus, Booth, Anthony J
- Authors: Rutaisire, Justus , Booth, Anthony J
- Date: 2005
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125864 , vital:35827 , https://doi.10.1007/s10641-004-5564-8
- Description: We investigated aspects of the reproductive biology of the cyprinid fish, Labeo victorianus, locally known as ningu, in the Kagera and Sio Rivers, Uganda. These rivers represent the last remaining refuges for this species within Uganda. L. victorianus is a highly fecund, potamodrometic fish that migrates upstream to spawn. Spawning is generally synchronised with the bimodal water level maxima observed within the rivers. There were, however, some deviations from this pattern. We caught sexually mature fish throughout the year in the Sio River, and noticed that spawing started before the second rainfall peak. Fish from the Kagera matured at significantly larger sizes than fish from the Sio River. Male and female fish, from both rivers, fed intensively during the non-breeding months accumulating significant fat reserves; a probable energy storage mechanism prior to their spawning migrations. The differences between the populations is probably a phenotypic response to differing abiotic factors such as river size, flow velocity and food availability.
- Full Text:
- Date Issued: 2005
- Authors: Rutaisire, Justus , Booth, Anthony J
- Date: 2005
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125864 , vital:35827 , https://doi.10.1007/s10641-004-5564-8
- Description: We investigated aspects of the reproductive biology of the cyprinid fish, Labeo victorianus, locally known as ningu, in the Kagera and Sio Rivers, Uganda. These rivers represent the last remaining refuges for this species within Uganda. L. victorianus is a highly fecund, potamodrometic fish that migrates upstream to spawn. Spawning is generally synchronised with the bimodal water level maxima observed within the rivers. There were, however, some deviations from this pattern. We caught sexually mature fish throughout the year in the Sio River, and noticed that spawing started before the second rainfall peak. Fish from the Kagera matured at significantly larger sizes than fish from the Sio River. Male and female fish, from both rivers, fed intensively during the non-breeding months accumulating significant fat reserves; a probable energy storage mechanism prior to their spawning migrations. The differences between the populations is probably a phenotypic response to differing abiotic factors such as river size, flow velocity and food availability.
- Full Text:
- Date Issued: 2005
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