~ 181 ~ International Journal of Fisheries and Aquatic Studies 2021; 9(6): 181-186 E-ISSN: 2347-5129 P-ISSN: 2394-0506 (ICV-Poland) Impact Value: 5.62 (GIF) Impact Factor: 0.549 IJFAS 2021; 9(6): 181-186 © 2021 IJFAS www.fisheriesjournal.com Received: 01-09-2021 Accepted: 03-10-2021 Oguntade Samuel Temitayo Department of Fisheries and Aquaculture Technology, Federal University of Technology, Akure, Ondo, Nigeria Olabode Thomas Adebayo Department of Fisheries and Aquaculture Technology, Federal University of Technology, Akure, Ondo, Nigeria Omoniyi Micheal Popoola Department of Fisheries and Aquaculture Technology, Federal University of Technology, Akure, Ondo, Nigeria Corresponding Author: Oguntade Samuel Temitayo Department of Fisheries and Aquaculture Technology, Federal University of Technology, Akure, Ondo, Nigeria Critical water quality parameters and certain non specific immune parameters of Clarias gariepinus juveniles raised in bioflocs system with cassava flour and rice bran as carbon sources Oguntade Samuel Temitayo, Olabode Thomas Adebayo and Omoniyi Micheal Popoola DOI: https://doi.org/10.22271/fish.2021.v9.i6c.2599 Abstract This study was conducted to examine effects of bioflocs culture on critical water parameters and certain non specific immune parameters in C. gariepinus juveniles. This experiment was conducted for 72 days, in 9 separate tanks with an aerated blower. Bioflocs culture had two different sources of carbon addition. This research consists of three treatments, carbon sources were added at CN ratio of 15:1. Results showed no significant difference in dissolved oxygen, pH, and temperature in all treatments. However, conductivity, Total dissolved solids and salinity showed significant difference across all treatment groups. Total ammonia nitrogen, nitrate and nitrite showed significant difference between control and bioflocs treatments. Blood parameters examined were serum lysozyme, myeloperoxidase activity, neutrophils, lymphocytes and monocytes percentage. Serum lysozyme and myeloperoxidase showed significant difference across treatments while neutrophils percentage showed significant difference between bioflocs culture and control experiment. Lymphocytes and monocytes showed no significant difference. Keywords: biofloc, immune system, nitrite, dissolved oxygen, neutrophils 1. Introduction Almost all the earth’s natural resources have been harnessed, farmed, or cultured for man’s various needs. These resources have benefited man in various ways which include provision of food, fuel, shelther, clothing and meeting the energy demands of man such as electricity, transportation e.t.c (FAO, 2010) [33] . However, as population increases, these resources decreased proportionally, in some particular cases these resources have depleted than they are being replenished while some cases have led to environmental pollution, loss of biodiversity, extinction of said resources and climate change e.t.c (FAO, 2014) [34] . Global fish production has grown steadily in the last five decades, with food fish supply increasing at an average annual rate of 3.2%, outpacing world population growth at 1.6%. World per capita apparent fish consumption increased from an average of 9.9 kg in the 1960s to 20.3kg in 2017 (FAO, 2018) [29] . The aquaculture industry is a substantial global industry supplying a significant proportion of the aquatic food consumed and other aquatic products that are valuable sources of protein and essential nutrient components for global food security (FAO, 2018) [29] . To support the rapidly growing human population globally, food production industries such as aquaculture require an approach toward improving the output with minimal cost. Aquaculture is an activity in constant growth that requires maximizing resources and spaces. The rapid growth of global aquaculture is faced with environmental and economic imitations. Employment in the sector has grown faster than the world’s population, the sector provides jobs to tens of millions and supports the livelihoods of hundreds of millions and fish continues to be one of the most traded food commodities worldwide (FAO, 2014) [32] . Amongst the challenges of aquaculture include competition for land and water resource, the introduction of exotic species around the globe, the over exploitation of ocean fish stocks to