Freshwater Snail Distribution Related to Physicochemical Parameters and Aquatic Macrophytes in Giza and Kafr El-Shiekh Governorates, Egypt

Abstract

A fi eld work was conducted to study the density of the freshwater snail in relation to the vegetation cover as well as the physical and chemical properties in different watercourses. Two sites were selected in Giza governorate while, three sites were selected at Kafr El-Shiekh governorate. Water temperature, conductivity, total hardness, and pH were measured in the selected sites as well as bisphenol A (BPA) levels. Snail sampling was carried out and all types of macrophytes found in each site were collected, identifi ed and coverage. Nine snails species namely Biomphalaria alexandrina, Physa acuta, Planorbis planorbis, Lymnaea natalensis, Bulinus truncates, Bellamya unicolor, Melanoides tuberculata, Helisoma duryi and Lanistes carinatus were identifi ed. B. alexandrina was the most enumeration of snail species. The percentage of total snail species (75.47 %) was recorded at 28 °C as compared to 5.86 % recorded at 34 °C. Five species of aquatic vegetation were identifi ed, two of them correlated positively and signifi cantly with various snail species. Sites in which snails associated with macrophytes were characterized with higher ranges of chemicals, dissolved oxygen, and conductivity. In conclusion, the most important of the associating vegetation was L. gibba which correlated with B. alexandrina and served as an indicator plant.

Environmental and biotic factors affecting freshwater snail intermediate hosts in the Ethiopian Rift Valley region

“…The increase in presence of B. pfeifferi and the increase in abundance of B. sudanica and Bu. globosus at sites with a high macrophyte cover observed in our study, indicate that food availability and the accessibility of aquatic weeds as a suitable surface on which egg masses of snails are deposited play an important role [21,62,75,76]. On the contrary, the decrease in abundance of Bu.…”

Abundance and annual distribution of freshwater snails and some trematode cercariae at Damietta Governorate, Egypt

“…(2010) , Mohammed et al . (2016) , and El-deeb et al . (2017) , many factors affect the density and distribution of snail species.…”

“…(2015) revealed that the mean values of water temperature ranged from 23.5 – 25.7°C at seven sites in the four northern Egyptian governorates; Giza, Ismailia, Menoufia, and Gharbia. The highest occurrence of the snail Biomphalaria alexandrina was recorded at 28°C and 31°C in two northern Egyptian governorates; Giza and Kafr El Shiekh ( El-deeb et al ., 2017 ). Salawu & Odaibo (2014) reported the suitability of the water temperature range 21.7 – 29°C in all river bodies at Ogun state, Nigeria, for the survival of aquatic snail species.…”

“…It is crucial to know the habitat, ecological factors, and distribution of the freshwater snails especially the medically and economically important species. Unfortunately, few studies addressed the ecology and population dynamics of the freshwater snails in Egypt ( Hussein et al ., 2011 ; Marie et al ., 2015 ; El-deeb et al ., 2017 ; Mahmoud & Sayed 2018 ). Because of this and the unique freshwater ecosystem of Damietta governorate, the present study aimed to (1) survey the freshwater snails in selected sites at Damietta governorate, (2) determine the abundance of these snails and the seasonal changes in their abundance, (3) investigate whether there is a correlation between the abundance of these snails and some physicochemical parameters, and (4) address the seasonal changes in the snails’ cercarial contents and investigate whether there is a correlation between their prevalence and some physicochemical parameters.…”

“…According toYirenya-Tawiah et al (2011), the temperature ranging from 27.4 -33°C is suitable for the survival of snails.Marie et al (2015) revealed that the mean values of water temperature ranged from 23.5 -25.7°C at seven sites in the four northern Egyptian governorates; Giza, Ismailia, Menoufia, and Gharbia. The highest occurrence of the snail Biomphalaria alexandrina was recorded at 28°C and 31°C in two northern Egyptian governorates; Giza and Kafr El Shiekh(El-deeb et al, 2017).Salawu & Odaibo (2014) reported the suitability of the water temperature range 21.7 -29°C in all river bodies at Ogun state, Nigeria, for the survival of aquatic snail species Islam et al (2015). revealed that the suitable water temperature needed for the development of gymnocephalus cercariae in Lymnaea sp.…”