Microbiological load evaluation of white shrimp (Nematopalaemon hastatus Aurivillius, 1898) in the coastal waters of Ondo state, Nigeria

A.O. Ajibare1*, O.O. Olawusi-Peters2, K.A. Oyinlola3

1Department of Fisheries and Aquaculture Technology, Olusegun Agagu University of Science and Technology Okitipupa, Nigeria
2Department of Fisheries and Aquaculture Technology, Federal University of Technology Akure, Nigeria
3Department of Biological Sciences, KolaDaisi University Ibadan, Nigeria

(Manuscript received 30 November 2020; accepted for publication 31 August 2021)

Abstract. This study investigated the condition factor with microbial load of Nematopalaemon hastatus (Aurivillius, 1898) collected for two years from four coastal towns in Ilaje communities of Ondo State, Nigeria. Shrimps’ weight, length and condition factor were determined using standard methods while estimation of microbial load (Total heterotrophic bacteria, coliform, Escherichia coli, Salmonella/Shigella, and fungal counts) was done using standard microbiological methods. The correlation between microbial load and condition factor was thereafter determined using regression analysis. N. hastatus exhibited allometric growth, with low but consistent condition factor. Mean heterotrophic bacteria count was 1.107×102 CFU/g and 1.079×102 CFU/g during the dry and wet season, respectively. Mean coliform count, total Salmonella-Shigella and E. coli counts were 0.398×102 CFU/g, 0.218×102 CFU/g and 0.303×102 CFU/g, respectively, during the wet season. A significant increase in counts (mean) was observed in the dry season for the coliform (0.404×102 CFU/g), total Salmonella-Shigella (0.234×102 CFU/g) and E. coli (0.326×102 CFU/g). The mean fungal count was 0.604×102 SFU/g and 0.563×102 SFU/g during the wet and dry seasons, respectively. The microbial loads were below acceptable limits; therefore, shrimps of the study area are safe for consumption. Conclusively, the condition factor of the shrimps was non-significantly influenced by the microbes. However, there is a need to regulate and/or prevent untreated sewage and effluent discharge into natural water bodies to reduce the environmental hazards it may portend and also obtain relatively safe aquatic products for consumption.