abebe Getahun | Addis Ababa University (original) (raw)
Papers by abebe Getahun
Zoological Journal of The Linnean Society, 2007
A clarification of the morphological character data supporting the hypothesis of labeonin monophy... more A clarification of the morphological character data supporting the hypothesis of labeonin monophyly, and also for one of its subgroups, the Garraina, is presented. As an aid to ongoing studies, a full listing of putative labeonin genera is provided. Included in the Garraina is the widespread and taxonomically problematical Afro-Asian genus Garra. Getahun (2000) in an unpublished thesis clarified much of the taxonomic confusion surrounding the African members of this genus, and we summarize many of his conclusions in the form of an artificial identification key for all 17 valid species of Garra on the African continent. The diversity of Garra in Ethiopia, the geographical centre of species diversity for the genus in Africa, is resolved and redescriptions of the six species previously recognized in Ethiopian inland waters are provided, along with formal taxonomic descriptions of an additional five new species from that country. Four of the new species are endemic to Ethiopia: Garra regressus sp. nov., Garra duobarbis sp. nov., Garra geba sp. nov., and Garra tana sp. nov., whereas the fifth, Garra dembecha sp. nov., is more widespread and found also in Eritrea, Kenya, and Tanzania in eastern Africa. © 2007 The Linnean Society of London, Zoological Journal of the Linnean Society, 2007, 150, 41–83.
![Research paper thumbnail of Effect of stocking density on the growth performance and yield of Nile tilapia [ Oreochromis niloticus (L., 1758)] in a cage culture system in Lake Kuriftu, Ethiopia](https://attachments.academia-assets.com/47861593/thumbnails/1.jpg)
](Aquaculture Research, 2008
This research was conducted to investigate the effect of stocking density on the growth performan... more This research was conducted to investigate the effect of stocking density on the growth performance and yield of Oreochromis niloticus in cage culture in Lake Kuriftu. The treatments had stocking densities of 50 (50F), 100 (100F), 150 (150F), and 200 (200F) fish per m−3. All treatments were in duplicate. Juveniles with an average weight of 45. 76±0.25 g were stocked in the treatments. The fish were fed a composite mixture of mill sweeping, cotton seed, and Bora food complex at 2% of their body weight twice per day using feeding trays for 150 days in powdered form. The growth performance of O. niloticus was density dependent. The final mean weight of O. niloticus ranged 147.76±0.28–219.71±1.42 g and the mean daily weight gain was 0.69±0.01–1.15±0.02 g day−1. Fish held in cages with lower density were heavier than the ones held at higher densities, and showed higher weight gain and daily weight gain. The most effective stocking density, in terms of growth parameters, was 50 fish m−3. The gross yield (4.5–20.55 kg cage−1) showed a significant difference with increasing stocking density (P<0.05). Moreover, the apparent food conversion ratio (2.48–7.22) was significantly affected by stocking density (P<0.05). However, survival rate was not affected by stocking density (P>0.05). It can be concluded that the most effective stocking densities were at 50 fish m−3 cage for larger size fish demand in a short period and 200 fish m−3 for higher gross production with supplementary feed.
Hydrobiologia, 2009
An out-of-Africa dispersal route has been proposed for many organisms, including modern man. Howe... more An out-of-Africa dispersal route has been proposed for many organisms, including modern man. However, counter examples of in-to-Africa dispersal routes are less common. In the present article, the phylogenetic relationships within the Labeoninae, a subfamily of cyprinid fishes distributed in Asia and Africa, were analyzed to investigate the biogeographic processes governing the modern distribution of these Asian and African cyprinids. The mitochondrial DNA cytochrome b gene was used as a molecular marker. The phylogenetic analysis indicated that the subfamily Labeoninae is a monophyletic group, with some Asian labeonins located at the basal position. Two subclades were found that contained both African and Asian species, which highlighted a need for further biogeographic analysis. Based on this analysis, it is proposed that the centre of origin of the Labeoninae was in East Asia. Molecular clock estimation suggests that the Labeoninae arose by the Early Miocene (~23 MYA) during the period of the second Tibetan uplift. Subsequently, two dispersal events of labeonins from Asia into Africa occured in the Early Miocene (~ 20 MYA) and Late Miocene (~9 MYA) and serve as examples counter to out-of-Africa dispersal.
Hydrobiologia, 2009
An out-of-Africa dispersal route has been proposed for many organisms, including modern man. Howe... more An out-of-Africa dispersal route has been proposed for many organisms, including modern man. However, counter examples of in-to-Africa dispersal routes are less common. In the present article, the phylogenetic relationships within the Labeoninae, a subfamily of cyprinid fishes distributed in Asia and Africa, were analyzed to investigate the biogeographic processes governing the modern distribution of these Asian and African cyprinids. The mitochondrial DNA cytochrome b gene was used as a molecular marker. The phylogenetic analysis indicated that the subfamily Labeoninae is a monophyletic group, with some Asian labeonins located at the basal position. Two subclades were found that contained both African and Asian species, which highlighted a need for further biogeographic analysis. Based on this analysis, it is proposed that the centre of origin of the Labeoninae was in East Asia. Molecular clock estimation suggests that the Labeoninae arose by the Early Miocene (~23 MYA) during the period of the second Tibetan uplift. Subsequently, two dispersal events of labeonins from Asia into Africa occured in the Early Miocene (~ 20 MYA) and Late Miocene (~9 MYA) and serve as examples counter to out-of-Africa dispersal.
Hydrobiologia, 2009
An out-of-Africa dispersal route has been proposed for many organisms, including modern man. Howe... more An out-of-Africa dispersal route has been proposed for many organisms, including modern man. However, counter examples of in-to-Africa dispersal routes are less common. In the present article, the phylogenetic relationships within the Labeoninae, a subfamily of cyprinid fishes distributed in Asia and Africa, were analyzed to investigate the biogeographic processes governing the modern distribution of these Asian and African cyprinids. The mitochondrial DNA cytochrome b gene was used as a molecular marker. The phylogenetic analysis indicated that the subfamily Labeoninae is a monophyletic group, with some Asian labeonins located at the basal position. Two subclades were found that contained both African and Asian species, which highlighted a need for further biogeographic analysis. Based on this analysis, it is proposed that the centre of origin of the Labeoninae was in East Asia. Molecular clock estimation suggests that the Labeoninae arose by the Early Miocene (~23 MYA) during the period of the second Tibetan uplift. Subsequently, two dispersal events of labeonins from Asia into Africa occured in the Early Miocene (~ 20 MYA) and Late Miocene (~9 MYA) and serve as examples counter to out-of-Africa dispersal.
Zoological Journal of The Linnean Society, 2007
A clarification of the morphological character data supporting the hypothesis of labeonin monophy... more A clarification of the morphological character data supporting the hypothesis of labeonin monophyly, and also for one of its subgroups, the Garraina, is presented. As an aid to ongoing studies, a full listing of putative labeonin genera is provided. Included in the Garraina is the widespread and taxonomically problematical Afro-Asian genus Garra. Getahun (2000) in an unpublished thesis clarified much of the taxonomic confusion surrounding the African members of this genus, and we summarize many of his conclusions in the form of an artificial identification key for all 17 valid species of Garra on the African continent. The diversity of Garra in Ethiopia, the geographical centre of species diversity for the genus in Africa, is resolved and redescriptions of the six species previously recognized in Ethiopian inland waters are provided, along with formal taxonomic descriptions of an additional five new species from that country. Four of the new species are endemic to Ethiopia: Garra regressus sp. nov., Garra duobarbis sp. nov., Garra geba sp. nov., and Garra tana sp. nov., whereas the fifth, Garra dembecha sp. nov., is more widespread and found also in Eritrea, Kenya, and Tanzania in eastern Africa. © 2007 The Linnean Society of London, Zoological Journal of the Linnean Society, 2007, 150, 41–83.
Aquaculture Research, 2008
This research was conducted to investigate the effect of stocking density on the growth performan... more This research was conducted to investigate the effect of stocking density on the growth performance and yield of Oreochromis niloticus in cage culture in Lake Kuriftu. The treatments had stocking densities of 50 (50F), 100 (100F), 150 (150F), and 200 (200F) fish per m−3. All treatments were in duplicate. Juveniles with an average weight of 45. 76±0.25 g were stocked in the treatments. The fish were fed a composite mixture of mill sweeping, cotton seed, and Bora food complex at 2% of their body weight twice per day using feeding trays for 150 days in powdered form. The growth performance of O. niloticus was density dependent. The final mean weight of O. niloticus ranged 147.76±0.28–219.71±1.42 g and the mean daily weight gain was 0.69±0.01–1.15±0.02 g day−1. Fish held in cages with lower density were heavier than the ones held at higher densities, and showed higher weight gain and daily weight gain. The most effective stocking density, in terms of growth parameters, was 50 fish m−3. The gross yield (4.5–20.55 kg cage−1) showed a significant difference with increasing stocking density (P<0.05). Moreover, the apparent food conversion ratio (2.48–7.22) was significantly affected by stocking density (P<0.05). However, survival rate was not affected by stocking density (P>0.05). It can be concluded that the most effective stocking densities were at 50 fish m−3 cage for larger size fish demand in a short period and 200 fish m−3 for higher gross production with supplementary feed.
Hydrobiologia, 2009
An out-of-Africa dispersal route has been proposed for many organisms, including modern man. Howe... more An out-of-Africa dispersal route has been proposed for many organisms, including modern man. However, counter examples of in-to-Africa dispersal routes are less common. In the present article, the phylogenetic relationships within the Labeoninae, a subfamily of cyprinid fishes distributed in Asia and Africa, were analyzed to investigate the biogeographic processes governing the modern distribution of these Asian and African cyprinids. The mitochondrial DNA cytochrome b gene was used as a molecular marker. The phylogenetic analysis indicated that the subfamily Labeoninae is a monophyletic group, with some Asian labeonins located at the basal position. Two subclades were found that contained both African and Asian species, which highlighted a need for further biogeographic analysis. Based on this analysis, it is proposed that the centre of origin of the Labeoninae was in East Asia. Molecular clock estimation suggests that the Labeoninae arose by the Early Miocene (~23 MYA) during the period of the second Tibetan uplift. Subsequently, two dispersal events of labeonins from Asia into Africa occured in the Early Miocene (~ 20 MYA) and Late Miocene (~9 MYA) and serve as examples counter to out-of-Africa dispersal.
Hydrobiologia, 2009
An out-of-Africa dispersal route has been proposed for many organisms, including modern man. Howe... more An out-of-Africa dispersal route has been proposed for many organisms, including modern man. However, counter examples of in-to-Africa dispersal routes are less common. In the present article, the phylogenetic relationships within the Labeoninae, a subfamily of cyprinid fishes distributed in Asia and Africa, were analyzed to investigate the biogeographic processes governing the modern distribution of these Asian and African cyprinids. The mitochondrial DNA cytochrome b gene was used as a molecular marker. The phylogenetic analysis indicated that the subfamily Labeoninae is a monophyletic group, with some Asian labeonins located at the basal position. Two subclades were found that contained both African and Asian species, which highlighted a need for further biogeographic analysis. Based on this analysis, it is proposed that the centre of origin of the Labeoninae was in East Asia. Molecular clock estimation suggests that the Labeoninae arose by the Early Miocene (~23 MYA) during the period of the second Tibetan uplift. Subsequently, two dispersal events of labeonins from Asia into Africa occured in the Early Miocene (~ 20 MYA) and Late Miocene (~9 MYA) and serve as examples counter to out-of-Africa dispersal.
Hydrobiologia, 2009
An out-of-Africa dispersal route has been proposed for many organisms, including modern man. Howe... more An out-of-Africa dispersal route has been proposed for many organisms, including modern man. However, counter examples of in-to-Africa dispersal routes are less common. In the present article, the phylogenetic relationships within the Labeoninae, a subfamily of cyprinid fishes distributed in Asia and Africa, were analyzed to investigate the biogeographic processes governing the modern distribution of these Asian and African cyprinids. The mitochondrial DNA cytochrome b gene was used as a molecular marker. The phylogenetic analysis indicated that the subfamily Labeoninae is a monophyletic group, with some Asian labeonins located at the basal position. Two subclades were found that contained both African and Asian species, which highlighted a need for further biogeographic analysis. Based on this analysis, it is proposed that the centre of origin of the Labeoninae was in East Asia. Molecular clock estimation suggests that the Labeoninae arose by the Early Miocene (~23 MYA) during the period of the second Tibetan uplift. Subsequently, two dispersal events of labeonins from Asia into Africa occured in the Early Miocene (~ 20 MYA) and Late Miocene (~9 MYA) and serve as examples counter to out-of-Africa dispersal.