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Abundance of the collected snail species and prevalence of the cercarial types recovered from five sites in Damietta Governorate_
| Snail species | Al-Inaniyyah village | Izbat Al-Basartah village | EL-Shenawy village | EL-Serw | Kafr EL-Manazlla village | Total | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| No. | % | No. | % | No. | % | No. | % | No. | % | No. | % | |
| Lanistes carinatus | 200 | 43.1 | 172 | 43.77 | 174 | 68.77 | 167 | 69.01 | 147 | 85.47 | 860 | 56.43 |
| Lanistes varicus | 117 | 25.22 | 79 | 20.10 | 44 | 17.4 | 41 | 16.94 | 25 | 14.53 | 306 | 20.08 |
| Pila wernei | 24 | 5.17 | 19 | 4.83 | 0 | 0 | 0 | 0 | 0 | 0 | 43 | 2.82 |
| Segmentorbis angustus | 50 | 10.78 | 82 | 20.87 | 35 | 13.83 | 34 | 14.05 | 0 | 0 | 201 | 13.2 |
| Melanoides tuberculata | 24 | 5.17 | 18 | 4.58 | 0 | 0 | 0 | 0 | 0 | 0 | 42 | 2.76 |
| Biomphalaria alexandrina | 24 | 5.17 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 24 | 1.57 |
| Gabbiella senoriansis | 25 | 5.39 | 23 | 5.85 | 0 | 0 | 0 | 0 | 0 | 0 | 48 | 3.14 |
| Total No. of snail species in each site | 464 | 393 | 253 | 242 | 172 | 1524 | ||||||
| Cercariae type % | ||||||||||||
| Gymnocephalus cercariae | 3 | 0 | 0 | 0 | 9.52 | 2.32 | ||||||
| Xiphidiocercariae | 6 | 5.81 | 2.87 | 2.39 | 5.44 | 4.53 | ||||||
Seasonal changes in the abundance of snail species and the prevalence of cercaria types in Damietta Governorate_
| Seasons | |||||
|---|---|---|---|---|---|
| Snail species | Winter | Spring | Summer | Autumn | P- value |
| %±SD | %±SD | %±SD | %±SD | ||
| Lanistes carinatus | 2.85±2.84 | 4.90±2.23 | 7.28±1.43 | 5.20±1.81 | 0.000 |
| Lanistes varicus | 0.26±0.33 | 1.56±0.71 | 2.80±0.65 | 1.55±0.93 | 0.000 |
| Pila wernei | 0.41±0.57 | 0.04±0.16 | 0.01±0.05 | 0.18±0.3 | 0.007 |
| Segmentorbis angustus | 1.54±1.93 | 1.02±2.02 | 0 | 0 | 0.006 |
| Melanoides tuberculata | 0 | 0.33±0.93 | 0.22±0.62 | 0 | 0.26 |
| Biomphalaria alexandrina | 0 | 0.11±0.44 | 0.25±0.62 | 0 | 0.3 |
| Gabbiella senoriansis | 0 | 0.21±0.46 | 0.60±0.78 | 0.04±0.16 | 0.003 |
| Cercariae type | %±SD | %±SD | %± SD | %±SD | P-value |
| Gymnocephalus cercariae | 0 | 4.05±7.13 | 3.76±9.24 | 0.55±2.15 | 0.14 |
| Xiphidiocercariae | 1.5±3.98 | 0.36±1.42 | 9.57±7.66 | 1.64±4.62 | 0.00 |
Monte Carlo test for evaluating the significance of environmental parameters in Damietta Governorate_
| Variables | Variance explained | F-ratio | P-value |
|---|---|---|---|
| Temp. | 0.23 | 14.05 | 0.002 |
| Ec | 0.04 | 2.26 | 0.06 |
| pH | 0.01 | 0.73 | 0.596 |
| Do | 0 | 0.36 | 0.832 |
| TDS | 0.01 | 0.19 | 0.812 |
Correlation analysis of the relationship between the physicochemical parameters of water and both of the snail abundance and cercaria prevalence in Damietta Governorate_
| Snail species | Temp. °C | Do.mg/L | TDS ppm | EC μS/cm | pH |
|---|---|---|---|---|---|
| Lanistes carinatus | 0.653** | -0.587** | -0.651** | -0.428** | -0.074 |
| Lanistes varicus | 0.874** | -0.715** | -0.247 | -0.155 | -0.111 |
| Pila wernei | -0.415** | 0.329* | 0.454** | 0.507** | -0.125 |
| Segmentorbis angustus | -0.496** | 0.425** | 0.189 | 0.170 | -0.043 |
| Melanoides tuberculata | 0.124 | -0.074 | -0.008 | -0.030 | -0.057 |
| Biomphalaria alexandrina | 0.158 | -0.172 | 0.032 | 0.074 | 0.040 |
| Gabbiella senoriansis | 0.383** | -0.450** | 0.028 | -0.071 | -0.072 |
| Cercaria type | |||||
| Gymnocephalus cercariae | 0.203 | 0.146 | -0.11 | -0.112 | 0.080 |
| Xiphidiocercariae | 0.494** | -0.522** | -0.031 | -0.140 | -0.121 |
Variability of water physicochemical parameters among the sites of snail collection in Damietta Governorate_
| Sites | Temp. °C | Do. mg/L | TDS Ppm | EC μS/cm | pH |
|---|---|---|---|---|---|
| Al-Inaniyyah | 21.95±6.20 | 6.74±0.95 | 823.58±439.28 | 1380±650 | 7.59±0.30 |
| Izbat Al-Basartah village | 22.08±6.52 | 6.44±0.95 | 669.75±368.12 | 850±320 | 7.47±0.29 |
| EL-Shenawy village | 21.83±6.90 | 6.61±0.92 | 433.08±126.44 | 640±180 | 7.74±0.35 |
| EL-Serw | 21.75±6.48 | 6.66±1 | 624.08±362.63 | 920±530 | 7.58±0.40 |
| Kafr EL-Manazlla village | 22.29±6.01 | 7.02±0.61 | 385.50±88.93 | 570±1300 | 7.59±0.30 |
Biodiversity indices of the freshwater snails collected from five sites in Damietta Governorate_
| Snail species | Al-Inaniyyah village | Izbat Al-Basartah village | EL-Shenawy village | EL-Serw | Kafr EL-Manazlla village | P- value |
|---|---|---|---|---|---|---|
| Shannon – index (H) | 1.44±0.49 | 1.21±0.27 | 0.77±0.16 | 1.04±0.71 | 0.62±0.13 | 0.086 |
| Richness – index (d) | 0.69±0.24 | 0.5±0.13 | 0.2±0.2 | 0.27±0.1 | 0.19 | 0.64 |
| Evenness – index (E) | 0.86±0.16 | 0.78±0.36 | 0.89±0.21 | 1.1±0.56 | 0.9±0.18 | 0.002 |