Species Diversity, Distribution, and Abundance of Freshwater Snails in KwaZulu-Natal, South Africa

Abstract

Disease distribution is correlated to the distribution of the freshwater snails which in turn is influenced by the physicochemical status of the habitats. This study aimed to evaluate freshwater snail species diversity, abundance, and distribution in KwaZulu-Natal (KZN) province, South Africa, between December 2020 to February 2021. A total of 4576 freshwater snails consisting of 8 species were collected from 127 sites in 11 districts. Tarebia granifera snails were the most abundant (n = 2201), while bivalves (n = 95) were the least abundant. The highest and least Shannon–Weiner Simpson’s diversity indices were recorded in Ugu and iLembe districts, respectively. A negative relationship was observed between rainfall, Bulinus tropicus, Lymnaea natalensis, bivalves, and Physa acuta, while temperature had a positive relationship with B. globosus, B. pfeifferi, and T. granifera. A positive relationship was observed between B. globosus and B. pfeifferi (r = 0.713, p < 0.05). Snail presence constitutes potential health and economic risks to humans and animals in contact with the waterbody. Hence, our study described the current distribution, abundance, and species diversity of freshwater snails in the KZN province with insights into the possibilities of snail-based biological control for schistosomes intermediate host snails.

Spatial distribution, abundance, and infection rates of human schistosome-transmitting snails and related physicochemical parameters in KwaZulu-Natal (KZN) province, South Africa

“…Although water velocity was not measured in this study, Bu. globosus snails are not found in water exceeding 0.3 m/s as they cannot attach themselves to the rocks [ 34 ]. Annual rainfall higher than 1192.2 mm leads to higher humidity, negatively impacting snail populations.…”

Spatial and seasonal distribution of human schistosomiasis intermediate host snails and their interactions with other freshwater snails in 7 districts of KwaZulu-Natal province, South Africa

“…Other freshwater snails such as Bulinus tropicus , Bulinus forskalii , Physa acuta , Tarebia granifera, and Bivalves, which are not intermediate host for human schistosomiasis have to a lesser extent been studied in KwaZulu-Natal compared to human schistosomiasis intermediate host snails: Bulinus globosus and Biomphalaria pfeifferi 7 . Previous studies have shown the effects of water physicochemical parameters such as water temperature, pH, dissolved oxygen, total dissolved solids, electrical conductivity, and climatic factors such as land surface temperature and rainfall on the distribution and abundance of freshwater snails 6 , 7 .…”

“…A cross-sectional study on the diversity, distribution and abundance of freshwater snails in all the districts in KZN province has also been carried out 7 . However, the study lacked information on temporal and seasonal patterns of freshwater snails in KZN as the study was cross-sectional based and accounted for the rainy season only.…”

Seasonal and environmental dynamics of intra-urban freshwater habitats and their influence on the abundance of Bulinus snail host of Schistosoma haematobium in the Tiko endemic focus, Mount Cameroon region

“…Some studies have shown a positive correlation between other freshwater snails ( Tarebia granifera ) and Bulinus globosus [ 67 , 68 ] whereas a recent study showed a negative correlation, though not significant, between B . globosus and the invasive Physa acuta [ 69 ]. This finding has implication for further investigation as research has shown that P .…”