A review of various factors affecting parasite assemblages in fish hosts is presented. These factors are broadly divided into two: Biotic and abiotic factors. Biotic factors such as host age and size, host size and parasites size, host specificity, host diet and host sex and their influence on the abundance and distribution of parasites are considered and highlighted. Equally, seasonality and other environmental factors that may facilitate the establishment and proliferations of parasites in host populations are also highlighted.

This study reviews the effects of parasites of fresh water fish hosts. Like other living organisms, fish harbour parasites either external or internal which cause a host of pathological debilities in them. The parasites live in close obligate association and derive benefits such as nutrition at the host's expense, usually without killing the host. They utililize energy otherwise available for the hosts growth, sustenance, development, establishment and reproduction and as such may harm their hosts in a number of ways and affect fish production. The common parasites of fishes include the unicellular microparasites (viruses, bacteria, fungi and protozoans). The protozoans i.e. microsporidians and mixozoans are considered in this review. The multicellular macroparasites mainly comprised of the helminthes and arthropods are also highlighted. The effects of parasites on their fish hosts maybe exacerbated by different pollutants including heavy metals and hydrocarbons, organic enrichment of sediments by domestic sewage and others such as parasite life cycles and fish population size.

DNA barcoding is a widely used molecular approach for species cataloging for unambiguous identification and conservation. In the present study, DNA barcoding of some West African mammals were performed with six new mitochondrial CO1 sequences for Civettictis civetta, Tadarida nigeriae, Orycteropus afer, Heliosciurus gambianus, Equus africanus asinus and Funisciurus anerythrus which are absent in public databases such as BLAST/NCBI and BOLD. Sequence identifications were made by comparing unknown sequences against the DNA barcodes of known species through distance-based tree construction and alignment probing. The sequences have been deposited to GenBank/NCBI.

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In this research, mass production of freshwater rotifer, Branchionus calyciflorus, for aquaculture in southeastern Nigeria, using different food types (Chlorella sp., Spirulina sp and Baker's yeast) was investigated. Rotifer stock culture was prepared using Nitrogen phosphorus Potassium, (NPK) + urea (50 : 2.5 g) and chicken droppings (25 g) with freshly grown alga. Different food concentrations (150, 300, 650 and 1000 mg/ml) and feeding intervals (2x and 3x per day) were used to grow B. calyciflorus in a Batch culture method. The highest population growth was attained with 650 mg/ml of Chlorella sp. (213.81±9.94 individuals/ml), followed by Baker's yeast (196.67±8.18 individuals/ml) and 300 mg/ml of Spirulina sp. (151.90±7.98 individuals/ml). The least population growth of B. calyciflorus was recorded with 150 mg/ml concentration of Chlorella sp. and Spirulina sp. (81.43±6.19 and 75.71±5.12 individuals/ml, respectively), and 1000 mg/ml of Baker's yeast (from local market) (65.24 ±3.86 individuals/ml). The peak population growth was attained on day 8 of experiment (p < 0.05). This study indicated that both the quantity and quality of food type have significant role on mass production of rotifer for aquaculture.