The phylogenetic relationships among “Barbus” species (Barbus jacksonii, B. paludinosus and B. trimaculatus) from Malagarasi and Pangani River systems were examined by partial mitochondrial cytochrome b (cyt.b) gene...The phylogenetic relationships among “Barbus” species (Barbus jacksonii, B. paludinosus and B. trimaculatus) from Malagarasi and Pangani River systems were examined by partial mitochondrial cytochrome b (cyt.b) gene. Sequences of the same samples from elsewhere in Africa obtained from the South African Institute of Aquatic Biodiversity (SAIAB’s) collection were also included in the analysis. Molecular technique was necessary due to phenotypic plasticity and extensive overlap of morphological features among the “Barbus species”. The findings of this study revealed that B. paludinosus from hale and Pangani populations occurred in two distinct genetic lineages though separated by a distance of approximately 10 km apart. Similar results were also noted amongst the population of B. paludinosus in Songati and Muumbara located on Lake Sagara in Malagarasi River basin. B. trimaculatus and B. jacksonii were indistinguishable such that it is envisaged that the two species are one and the same. The Barbus spp. from Africa included in the current study showed genetic affinity to neither European Barbus spp. nor South African redfins of the Pseudobarbus to conclude that the studied species of barbs are taxonomically quite different that needs further investigation to warrant renaming.展开更多
The alimentary canal contents of 360 Barbus luteus caught from MOD between January 2010 to December 2010 were examined. The phyto-plankton, zooplanktons, detritus, diatoms, insects and unidentified digestive food were...The alimentary canal contents of 360 Barbus luteus caught from MOD between January 2010 to December 2010 were examined. The phyto-plankton, zooplanktons, detritus, diatoms, insects and unidentified digestive food were identified in the alimentary canal of fish. The results of diet analysis showed that the B. luteus was omnivorous. The species of fish tended to consume more plant origin food. The aquatic plants and tissues were the main part of thier food followed by chlorophyta and cyanophyta. The results revealed that the species obtained or fell their food item from the bed of rivers or near to it.展开更多
In this study, Enteromius parablabes [1] was analyzed with the aim of providing baseline information regarding the diploid chromosome number and karyotype differences of both sexes. The diploid chromosome number (2n) ...In this study, Enteromius parablabes [1] was analyzed with the aim of providing baseline information regarding the diploid chromosome number and karyotype differences of both sexes. The diploid chromosome number (2n) was 50 for both sexes, and this corresponds to the diploid chromosome number reported for most small African Barbus species. The fundamental number (NFa) of the male and female was 81 and 98 respectively. The first pair of metaphase chromosomes which has been suggested to be a marker for the small African Barbus group was conspicuously larger in the female karyotype. The karyotype of the female consisted more of metacentric (39m + 7sm + 2st + 2t) which is common in the group while the karyotype of the male which consisted more of telocentric chromosomes (10m + 21st + 19T) is scarce. The chromosomal number obtained for E. parablabes demonstrates its diploid status in the context of the ploidy lines characteristic of the African Barbus assemblage.展开更多
The chromosomes of male and female individuals of Enteromius callipterus [1] were assessed in this study with the objective of determining the diploid chromosome and karyotype. The samples were obtained from the Tahos...The chromosomes of male and female individuals of Enteromius callipterus [1] were assessed in this study with the objective of determining the diploid chromosome and karyotype. The samples were obtained from the Tahoss River, Jos Plateau, and the assessment of the chromosomes was conducted using the conventional Giemsa staining technique. The study reveals that the male individual of E. callipterus has a diploid chromosome number of 2n = 50, the fundamental number of autosomal arms (NFa) of 82, and a karyotype formula of 2n = 14M + 4m + 32t. However, none of the spreads obtained for the female individuals were either equal to or below the common diploid chromosome number of 50 known for members of the genus. The two spreads presented here were of 2n equal to 54 and 58. Although sex dimorphism is rare within the genus, the present results suggest E. callipterus show sexual dimorphism at the chromosomal level.展开更多
文摘The phylogenetic relationships among “Barbus” species (Barbus jacksonii, B. paludinosus and B. trimaculatus) from Malagarasi and Pangani River systems were examined by partial mitochondrial cytochrome b (cyt.b) gene. Sequences of the same samples from elsewhere in Africa obtained from the South African Institute of Aquatic Biodiversity (SAIAB’s) collection were also included in the analysis. Molecular technique was necessary due to phenotypic plasticity and extensive overlap of morphological features among the “Barbus species”. The findings of this study revealed that B. paludinosus from hale and Pangani populations occurred in two distinct genetic lineages though separated by a distance of approximately 10 km apart. Similar results were also noted amongst the population of B. paludinosus in Songati and Muumbara located on Lake Sagara in Malagarasi River basin. B. trimaculatus and B. jacksonii were indistinguishable such that it is envisaged that the two species are one and the same. The Barbus spp. from Africa included in the current study showed genetic affinity to neither European Barbus spp. nor South African redfins of the Pseudobarbus to conclude that the studied species of barbs are taxonomically quite different that needs further investigation to warrant renaming.
文摘The alimentary canal contents of 360 Barbus luteus caught from MOD between January 2010 to December 2010 were examined. The phyto-plankton, zooplanktons, detritus, diatoms, insects and unidentified digestive food were identified in the alimentary canal of fish. The results of diet analysis showed that the B. luteus was omnivorous. The species of fish tended to consume more plant origin food. The aquatic plants and tissues were the main part of thier food followed by chlorophyta and cyanophyta. The results revealed that the species obtained or fell their food item from the bed of rivers or near to it.
文摘In this study, Enteromius parablabes [1] was analyzed with the aim of providing baseline information regarding the diploid chromosome number and karyotype differences of both sexes. The diploid chromosome number (2n) was 50 for both sexes, and this corresponds to the diploid chromosome number reported for most small African Barbus species. The fundamental number (NFa) of the male and female was 81 and 98 respectively. The first pair of metaphase chromosomes which has been suggested to be a marker for the small African Barbus group was conspicuously larger in the female karyotype. The karyotype of the female consisted more of metacentric (39m + 7sm + 2st + 2t) which is common in the group while the karyotype of the male which consisted more of telocentric chromosomes (10m + 21st + 19T) is scarce. The chromosomal number obtained for E. parablabes demonstrates its diploid status in the context of the ploidy lines characteristic of the African Barbus assemblage.
文摘The chromosomes of male and female individuals of Enteromius callipterus [1] were assessed in this study with the objective of determining the diploid chromosome and karyotype. The samples were obtained from the Tahoss River, Jos Plateau, and the assessment of the chromosomes was conducted using the conventional Giemsa staining technique. The study reveals that the male individual of E. callipterus has a diploid chromosome number of 2n = 50, the fundamental number of autosomal arms (NFa) of 82, and a karyotype formula of 2n = 14M + 4m + 32t. However, none of the spreads obtained for the female individuals were either equal to or below the common diploid chromosome number of 50 known for members of the genus. The two spreads presented here were of 2n equal to 54 and 58. Although sex dimorphism is rare within the genus, the present results suggest E. callipterus show sexual dimorphism at the chromosomal level.
