Browsing by Author "Mwita, Chacha J."

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    Environmental Contamination by Taenia Eggs in Iringa Rural District, Tanzania
    (2013) Mwita, Chacha J.; Tesha, Julius; Nkwengulila, Gamba
    Cysticercosis and Taeniosis are global health problems with impacts on human beings and the development of the livestock industry. This study tested the presence of Taenia eggs in the soil of two villages in Iringa rural district, Tanzania. No recognizable Taenia egg was found, though those found were difficult to identify due to absorption of the flotation fluid which made them dark with difficulties to see the innermost structures. In view of their sizes (30 - 40 microns in diameter) these eggs were considered to be of Taenia spp. In addition, eggs from four geo-helminth species were identified namely; Ascaris lumbricoides, Schistosoma mansoni, Strongyloides stercoralis and Trichuris trichiura eggs. The frequency of T. trichiura was 81.97%, Ascaris lumbricoides was 8.2%, unidentified eggs 6.01%, Strongyloides stercoralis 3.3% and Schistosoma mansoni was 0.5%. The most contaminated sites were backyard with a prevalence of 30.1% followed by west disposal site (WDS) 25.7%, open defaecation area (ODA) 24.0% and the least was toilet 20.2%. About 31 (31%) samples had no eggs. The findings revealed that the environment of Izazi village was more contaminated by geohelminth eggs (19.4%) than that of Migoli village (12.1%) and that higher moisture content in soils favors the growth, development, spread and transmission of geo-helminth eggs.
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    Fatty Acid Composition and Levels of Selected Polyunsaturated Fatty Acids in Four Commercial Important Freshwater Fish Species from Lake Victoria, Tanzania
    (Hindawi Publishing Corporation, 2014) Robert, Agnes; Mfilinge, Prosper; Samwel Mchele Limbu; Mwita, Chacha J.
    Fatty acids (FAs) particularly 𝜔3 and 𝜔6 polyunsaturated fatty acids (PUFAs) play important role in human health.This study aimed to investigate the composition and levels of selected 𝜔3 PUFAs in four commercial fish species, Nile perch (Lates niloticus), Nile tilapia (Oreochromis niloticus), Tilapia zillii, and dagaa (Rastrineobola argentea) from Mwanza Gulf in Lake Victoria. The results indicated that 36 types of FAs with different saturation levels were detected. These FAs were dominated by docosahexaenoic (DHA), eicosapentaenoic (EPA), docosapentaenoic (DPA), and eicosatetraenoic acids. O. niloticus had the highest composition of FAs (34) compared to L. niloticus (27), T. zillii (26), and R. argentea (21). The levels of EPA differed significantly among the four commercial fish species (𝐹 = 6.19, 𝑃 = 0.001). The highest EPA levels were found in R. argentea followed by L. niloticus and O. niloticus and the lowest in T. zillii. The DPA levels showed no significant difference among the four fish species studied (𝐹 = 0.652, 𝑃 = 0.583). The study concluded that all four commercial species collected from Mwanza Gulf are good for human health, but R. argentea is the best for consumption because it contains higher levels of 𝜔3 FAs, mainly EPA.
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    Molecular phylogeny of the clariid fishes of Lake Victoria, Tanzania, inferred from cytochrome b DNA sequences
    (2008) Mwita, Chacha J.; Nkwengulila, Gamba
    Mitochondrial DNA cytochrome b (cyt b) sequence variation among the clariid fishes of Lake Victoria and the Malagarasi wetland Tanzania were studied between August 2003 and February 2005. Seven species were sampled and together with 26 cyt b sequences from GenBank were used to reconstruct phylogenetic relationships in the family Clariidae. The study revealed two clades: one consisting of the big-head species, Clarias gariepinus and Heterobranchus longifilis, and the other of small-sized species, Clarias werneri, Clarias alluaudi, Clarias liocephalus and Clariallabes petricola. The study further revealed that the genus Clarias is paraphyletic and that H. longifilis clusters deeply inside the Clarias group. Although H. longifilis is thought to be the oldest in evolutionary age in Tanzania, it is not close to the ancestor of the Clariidae family. The results also showed that C. werneri and C. alluaudi are genetically distinct from each other.
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    The Risk Factors for Human Cysticercosis in Mbulu District, Tanzania
    (2014) Mwang’onde, Beda J.; Mwita, Chacha J.; Nkwengulila, Gamba
    The objective of this study was to explore the reasons for the persistence of human cysticercosis (HCC) transmission in Mbulu District, northern Tanzania. The study was carried out in 25 villages, whereby five major risks were identified. The risks were indiscriminate defaecation and improper use of toilets; a free-range system of keeping pigs; indiscriminate or unregulated slaughtering and inadequate meat hygiene and inspection; consumption of undercooked and porcine cysticerci infected pork; and social structure and roles. All of the identified risks were backed up by the immanent lifestyles of the community involved. These findings are important for the development of intervention strategies in the study area.
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    Spatial Patterns of Zooplankton Distribution and Abundance in Relation to Phytoplankton, Fish Catch and Some Water Quality Parameters at Shirati Bay, Lake Victoria-Tanzania
    (2016-03) Waya, Revania K.; Samwel Mchele Limbu; Ngupula, Godfrey W.; Mwita, Chacha J.; Mgaya, Yunus D.
    Spatial patterns and abundance of zooplankton in aquatic habitats are important determinants for production of fish species, invertebrates and availability of phytoplankton. Weekly monitoring for zooplankton abundance was conducted in Shirati Bay, Lake Victoria, to explore their spatial patterns in relation to phytoplankton, fish catch and some water quality parameters. The vertical distribution of zooplankton was generally higher close to the bottom as compared to surface waters of the lake. Zooplankton vertical distribution positively correlated with water transparency (r = 0.680, p = 0.011). The horizontal abundance of zooplankton was not significantly different amongst the three stations (p = 0.5143). While Copepoda was the dominant group in terms of composition, Rotifera had the highest diversity indices of all the zooplankton groups obtained. The abundance of nauplius larvae was significantly higher than that of the copepodites (p = 0.022). Nile perch, Lates niloticus dominated the total catches (47%) followed by Nile tilapia, Oreochromis niloticus (29%) and haplochromines (21%). The abundance of haplochromines and juvenile fishes correlated significantly with the abundance of zooplankton (r = 0.856, p = 0.002 and r = 0.58, p = 0.038, respectively). The current study revealed that zooplankton vertical distribution at Shirati Bay is mainly controlled by water transparency and predation by juvenile Nile perch, Nile tilapia and haplochromines.