Microalgae production in fresh market wastewater and its utilization as a protein substitute in formulated fish feed for oreochromis spp.

Rapid growing of human population has led to increasing demand of aquaculture production. Oreochromis niloticus or known as tilapia is one of the most globally cultured freshwater fish due to its great adaptation towards extreme environment. Besides, farming of tilapia not only involves small scales farming for local consumption but also larger scales for international market which contributes to a foreign currency earning. Extensive use of fishmeal as feed for fish and for other animals indirectly caused an increasing depletion of the natural resource and may consequently cause economic and environmental unstable. Microalgae biomass seems to be a promising feedstock in aquaculture industry. It can be used for many purposes such as live food for fish larvae and dried microalgae to substitute protein material in fish feed. The microalgae replacement in fish feed formulation as protein alternative seem potentially beneficial for long term aqua-business sustainability. The present chapter discussed the potential of microalgae as an alternative nutrition in fish feed formulations, specifically Tilapia

Electrical Conductivity of Alkali-silicate Glass containing Fe_2O_3.

Electrical resistivity (ρ) of Alkali-Silicate glasses has been measured to find out the behavior of Fe-ion in these glasses. ρ depends mainly upon the Fe^<2＋>/Fe total-ratio, and has the minimum peak. The behavior of Fe-ion at the minimum of ρ is discussed by the results of Mo^^¨ssbauer-spectra in terms of the oxygen-coordination number of Fe^<3＋>-ion. The mechanism of electrical conductance in these glasses is assumed to be the valence electron transfer between Fe^<2＋> and 6-fold oxygen Fe^<3＋>