Physicochemical Changes and Abundance of Freshwater Snails in Anambra River (Nigeria) During the Rainy Season

Abstract

Rapid diversification is a way of responding to environmental change for freshwater organisms. This work examined the physicochemical changes and abundance of freshwater snails in Anambra River (Nigeria) during the rainy season. Field studies were conducted fortnightly from June to August 2019 at three stations of the river namely: Otuocha (station I), Otunsugbe (station II), and Ukwubili (station III) about 8.35 kilometers apart from each other. A scoop net of 2 cm mesh size and handpicking was used to sample freshwater snails randomly and water samples were taken to the laboratory for physicochemical analysis. A total of 896 freshwater snails belonging to 6 species (Afropomus balanoidea, Pomacea maculata, Lymnea stagnalis, Lanistes ovum, Pila wernei, and Saulea vitrea) were collected. Pomacea maculata was the most dominant species with a relative abundance of 45.87 %, while Saulea vitrea was the least dominant species with a relative abundance of 2.34 %. There was a significant negative correlation between dissolved oxygen and Pomacea maculate (r = –0.877, p = 0.002) and a positive correlation between dissolved oxygen and Stagnalis lymnea (r = 0.840, p = 0.005). The diversity of species was highest at Otuocha (1.171) followed by Ukwubili (1.133) and Otunsugbe (0.856) with average mean temperatures of (23.1 ±0.1) °C, (27.30 ±0.00) °C, and (26.80 ±0.03) °C respectively. The distribution of freshwater snails was influenced by the physicochemical variability of Anambra River during the rainy season. Therefore, further studies for a longer time and different seasons to examine the impact of physicochemical changes on the snail distribution are encouraged.

Physicochemical Characteristics of Snail Breeding Habitats in Ndokwa West Lga, Delta State

“…Pearson correlation revealed no significant relationship between the water temperature and the abundance of snails throughout the season, with a significance level of 0.268 (P>0.05). This is in contrast to the findings of Okoye et al (2022) who recorded great abundance due to their endurance of a relatively high temperature. The high temperature recorded in this study can be attributed to the absence of shades in the Umoni and Adofi rivers, while in others there were partial shades.…”

“…The significant contributions of organic matter in the water, which led to their greater mineralization, are what account for the high levels of electrical conductivity at the Ase River. This finding is in disagreement with Okoye et al (2022), in a similar study in the Anambra River (Nigeria) during the rainy season, who reported a low electrical conductivity range of 8.25 S/cm to 10.7 S/cm. Based on the study of Tchakonte et al (2014), increased electrical conductivity affects the maturity and survival of snails and increases their abundance.…”

Assessment of Njaba River Quality Using Physico-Chemical Parameters

“…However, the pH values across the stations did not fall within the FMEnv recommended range of 6.50-8.50 for surface water. According to Enuneku et al [10] and Rim-Rukeh et al [11], acidic conditions in an aquatic body could be attributable to humic acid formed from decaying organic matter.…”

Panacea for the nanoplastic surge in Africa: A state-of-the-art review

“…Biodegradation of NPs usually involves the release of certain extracellular enzymes (such as hydrolases) by microorganisms, which transforms complex NP polymers into low molecular forms through biodeterioration, bio-fragmentation, biosynthesis, and mineralization [ 166 , 207 ]. This process is influenced by biotic (metabolic activity, the release of acids, enzymatic activity) [ 208 , 209 ], abiotic factors (surface morphology, topography, surface hydrophobicity, electric charge distribution), and other environmental conditions (such as temperature, pH, salinity, oxygen level) [ 207 , 210 ].…”