Browsing by Author "Amon P., Shoko"

Now showing 1 - 4 of 4
  • Thumbnail Image
    Item
    Effect of initial stocking size of the predatory African sharptooth catfish (Clarias gariepinus) on recruits, growth performance, survival and yield of mixed-sex Nile tilapia (Oreochromis niloticus) in concrete tank culture system
    (Springer, 2015-01-21) Samwel Mchele Limbu; Amon P., Shoko; Lamtane, Hieromin A.; Shirima, Evantuce D.; Kishe-Machumu, Mary A.; Mgana, Huruma F.; Mgaya, Yunus D.
    Prolific breeding and production of high percentage of recruits are main problems in mixed-sex Nile tilapia (Oreochromis niloticus) culture in earthen ponds. The current study assessed the efficiency of different sizes of African sharptooth catfish (Clarias gariepinus) in controlling recruitment in mixed-sex Nile tilapia cultured in tanks and its effect on growth performance, percentage survival and yield. Three treatments consisting of triplicate ponds stocked with mixed-sex Nile tilapia in monoculture and in polyculture with large (62.50 ± 3.26 g) and small (40.00 ± 2.68 g) African sharptooth catfish were fed on a 297.50 g kg-1 crude protein diet for 126 days. Results showed that, the number of recruits was significantly lower in larger African sharptooth catfish predator than smaller ones and monoculture of Nile tilapia. Polyculture with larger African sharptooth catfish resulted in significantly higher growth performance of Nile tilapia. Large African sharptooth catfish in polyculture reduced the amount of small, low-value recruits, while the yield of large and high value Nile tilapia was increased. This study revealed that fish farmers can reduce prolific breeding, obtain higher growth performance and produce larger size of marketable Nile tilapia by predominantly stocking ponds with large African sharptooth catfish predator of at least 60 g.
  • Thumbnail Image
    Item
    Effect of stocking density on growth performance, survival, production and economic benefits of African sharptooth catfish (Clarias gariepinus) monoculture in earthen ponds.
    (Springer, 2016-08-02) Amon P., Shoko; Samwel Mchele Limbu; Yunus D., Mgaya
    The present on-farm study assessed the effect of different stocking densities on growth, production, and financial benefits of African sharptooth catfish (Clarias gariepinus) in earthen ponds for 180 days. Low stocking density (LSD), medium stocking density (MSD), and high stocking density (HSD) of 3, 6, and 9 fish m−2, respectively, were tested. C. gariepinus stocked at LSD and MSD showed significantly higher weight gain, specific growth rate, and final mean weight than those cultured at HSD (P < .05). There was a significant linear relationship between the stocking density and the yields and financial variables (P < .05). Net fish yields were significantly higher for C. gariepinus reared at HSD and MSD than those stocked at LSD (P < .05). Similarly, C. gariepinus raised at MSD and HSD generated significantly more profit than those cultured at LSD (P < .05). Results demonstrated that farmers can achieve high net yield and financial benefits by stocking C. gariepinus at HSD of 9 fish m−2.
  • Thumbnail Image
    Item
    Fish polyculture system integrated with vegetable farming improves yield and economic benefits of small-scale farmers.
    (Wiley, 2016-09-12) Samwel Mchele Limbu; Amon P., Shoko; Hieromin Amon, Lamtane; Mary Alphonce, Kishe-Machumu; Masanja Charles, Jorum; Athanasio S., Mbonde; Huruma Fredrick, Mgana; Yunus Daud, Mgaya
    This study explored the yield and economic benefits of African sharptooth catfish, Clarias gariepinus, and Nile tilapia, Oreochromis niloticus polyculture, reared in earthen ponds for 270 days integrated with Chinese cabbage, Brassica rapa chinensis, farmed for 45 days to small‐scale farmers in Tanzania. An integrated aquaculture–agriculture (IAA) system involving fishes and vegetables resulted in three and 2.5 times higher net yield than the culture of fishes alone and farming of non‐integrated vegetables respectively. Vegetables irrigated with pond water resulted in 1.8 times higher net and annual yields than those irrigated with stream water. The practice of fish–vegetable integration and growing of vegetables irrigated with pond water produced 14 and 13 times higher net annual yield, respectively, than the culture of fishes alone. The integrated system produced 20 and 150 times more net returns compared with vegetables irrigated with pond and stream water respectively. Integrating fishes with vegetables resulted in significantly higher annual net cash flow than the farming of fishes and vegetables separately. The study revealed that integrating fishes with B. rapa chinensis increases yields, income and food production to small‐scale farmers. Thus, small‐scale farmers can adopt IAA technology to meet the increasing demand of fish and vegetables, stabilize their incomes and diversify food production, consequently improving food security. These benefits will be realized by providing proper training in IAA technology and management skills to small‐scale farmers.
  • Thumbnail Image
    Item
    Phytoplankton and food selectivity in Nile tilapia reared in earthen ponds under monoculture and polyculture with African Sharptooth catfish.
    (Multidisciplinary Digital Publishing Institute (MDPI), 2017-06-16) Athanasio S., Mbonde; Samwel Mchele Limbu; Amon P., Shoko; Yunus D., Mgaya
    Phytoplankton availability is one of the most important biotic factors affecting the successful culture of Nile tilapia (Oreochromis niloticus, Linnaeus) in semi-intensive ponds. The present study investigated phytoplankton composition, abundance and food selectivity in Nile tilapia Oreochromis niloticus (Linnaeus, 1758) reared in monoculture and polyculture system with African sharptooth catfish Clarias gariepinus (Burchell 1822) in earthen ponds. Water samples and stomachs of 144 O. niloticus were collected from respective pond systems for examination of phytoplankton composition and abundance. The obtained phytoplankton species in water and stomachs were used to determine food selectivity of O. niloticus. The results showed significantly higher Chlorophyceae in polyculture than monoculture ponds. The gut contents of O. niloticus from both systems were mainly composed of Bacillariophyceae, Euglenophyceae and Cyanophyceae and detritus and insect remains. Bacillariophyceae, detritus and insect remains were selected as food by O. niloticus cultured in both systems. Findings from this study show that, under monoculture and polyculture pond systems, O. niloticus exhibit selective feeding consuming more Bacillariophyceae, detritus and insect remains.The results suggest that fish farmers can practice either monoculture or polyculture of O. niloticus without affecting its food selectivity.