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

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

Helminthologia
Volume 58 (2021): Issue 3 (September 2021)
By: ,  ,   and    
Open Access
|Sep 2021
Figures & tables

Figures & Tables

Fig. 1

Location map showing study area in Damietta Governorate. Five sites were selected for this study; Al-Inaniyyah village; Izbat Al-Basartah village; EL-Shenawy village; EL-Serw and Kafr EL-Manazlla village.

Fig. 2

Snail species collected from different sites in Damietta Governorate. a: Pila wernei; b: Lanistes carinatus; c: Lanistes varicus; d: Gabbiella senoriansis; e: Biomphalaria alexandrina; f: Segmentorbis angustus, and g: Melanoides tuberculata. (Scale bar: 1cm and 4mm)

Fig. 3

Types of cercariae harvested from Lanistes carinatus collected from different sites in Damietta Governorate. a: Gymnocephalus cercariae; b: Xiphidiocercariae. Bo, Cercarial body; Cg, Cystogenous gland; Os, Oral sucker; T, Cercarial tail; Vs, Ventral sucker. (Scale bar: 25μm)

Table 1

Abundance of the collected snail species and prevalence of the cercarial types recovered from five sites in Damietta Governorate.

Snail speciesAl-Inaniyyah villageIzbat Al-Basartah villageEL-Shenawy villageEL-SerwKafr EL-Manazlla villageTotal
No.%No.%No.%No.%No.%No.%
Lanistes carinatus20043.117243.7717468.7716769.0114785.4786056.43
Lanistes varicus11725.227920.104417.44116.942514.5330620.08
Pila wernei245.17194.83000000432.82
Segmentorbis angustus5010.788220.873513.833414.050020113.2
Melanoides tuberculata245.17184.58000000422.76
Biomphalaria alexandrina245.1700000000241.57
Gabbiella senoriansis255.39235.85000000483.14
Total No. of snail species in each site4643932532421721524
Cercariae type %
Gymnocephalus cercariae30009.522.32
Xiphidiocercariae65.812.872.395.444.53

[i] Values represent the number (No.) and abundance (%) in case of a snails and the prevalence (%) in case of cercariae in each sampling site. Prevalence refers to the number of infected of snail species divided by the total number of the collected snail species. Abundance refers to the number of a specific snail species divided by the total number of the collected snail

Table 2

Biodiversity indices of the freshwater snails collected from five sites in Damietta Governorate.

Snail speciesAl-Inaniyyah villageIzbat Al-Basartah villageEL-Shenawy villageEL-SerwKafr EL-Manazlla villageP- value
Shannon – index (H)1.44±0.491.21±0.270.77±0.161.04±0.710.62±0.130.086
Richness – index (d)0.69±0.240.5±0.130.2±0.20.27±0.10.190.64
Evenness – index (E)0.86±0.160.78±0.360.89±0.211.1±0.560.9±0.180.002

[i] P values were considered significant if ≤0.05

Table 3

Seasonal changes in the abundance of snail species and the prevalence of cercaria types in Damietta Governorate.

Snail speciesWinterSpringSummerAutumnP- value
%±SD%±SD%±SD%±SD
Lanistes carinatus2.85±2.844.90±2.237.28±1.435.20±1.810.000
Lanistes varicus0.26±0.331.56±0.712.80±0.651.55±0.930.000
Pila wernei0.41±0.570.04±0.160.01±0.050.18±0.30.007
Segmentorbis angustus1.54±1.931.02±2.02000.006
Melanoides tuberculata00.33±0.930.22±0.6200.26
Biomphalaria alexandrina00.11±0.440.25±0.6200.3
Gabbiella senoriansis00.21±0.460.60±0.780.04±0.160.003
Cercariae type%±SD%±SD%± SD%±SDP-value
Gymnocephalus cercariae04.05±7.133.76±9.240.55±2.150.14
Xiphidiocercariae1.5±3.980.36±1.429.57±7.661.64±4.620.00

[i] SD, standard error; P values were considered significant if ≤0.05

Table 4

Variability of water physicochemical parameters among the sites of snail collection in Damietta Governorate.

SitesTemp. °CDo. mg/LTDS PpmEC μS/cmpH
Al-Inaniyyah21.95±6.206.74±0.95823.58±439.281380±6507.59±0.30
Izbat Al-Basartah village22.08±6.526.44±0.95669.75±368.12850±3207.47±0.29
EL-Shenawy village21.83±6.906.61±0.92433.08±126.44640±1807.74±0.35
EL-Serw21.75±6.486.66±1624.08±362.63920±5307.58±0.40
Kafr EL-Manazlla village22.29±6.017.02±0.61385.50±88.93570±13007.59±0.30
Table 5

Correlation analysis of the relationship between the physicochemical parameters of water and both of the snail abundance and cercaria prevalence in Damietta Governorate.

Snail speciesTemp. °CDo.mg/LTDS ppmEC μS/cmpH
Lanistes carinatus0.653**
(0.00)		-0.587**
(0.00)		-0.651**
(0.00)		-0.428**
(0.001)		-0.074
(0.576)
Lanistes varicus0.874**
(0.00)		-0.715**
(0.00)		-0.247
(0.057)		-0.155
(0.236)		-0.111
(0.397)
Pila wernei-0.415**
(0.001)		0.329*
(0.01)		0.454**
(0.00)		0.507**
(0.00)		-0.125
(0.343)
Segmentorbis angustus-0.496**
(0.00)		0.425**
(0.001)		0.189
(0.148)		0.170
(0.195)		-0.043
(0.747)
Melanoides tuberculata0.124
(0.346)		-0.074
(0.572)		-0.008
(0.95)		-0.030
(0.818)		-0.057
(0.665)
Biomphalaria alexandrina0.158
(0.227)		-0.172
(0.188)		0.032
(0.808)		0.074
(0.575)		0.040
(0.761)
Gabbiella senoriansis0.383**
(0.003)		-0.450**
(0.00)		0.028
(0.83)		-0.071
(0.588)		-0.072
(0.582)
Cercaria type
Gymnocephalus cercariae0.203
(0.119)		0.146
(0.267)		-0.11
(0.404)		-0.112
(0.395)		0.080
(0.542)
Xiphidiocercariae0.494**
(0.00)		-0.522**
(0.00)		-0.031
(0.813)		-0.140
(0.284)		-0.121
(0.356)

[i] P values (between brackets) were considered significant if ≤0.05; *, ** refer to high significance (0.01 and 0.001, respectively)

Fig. 4

Ordination diagram representing Canonical Correspondence Analysis of snail species and environmental variables in Damietta Governorate. a: Distribution of sampling sites and snail species along the gradients of environmental variables and b: Seasonal changes and snail species distributed along the gradients of environmental variables. (Ba: Biomphalaria alexandrina; Do: Dissolved oxygen; Ec: Electrical conductivity; Ga: Gabbiella senoriansis; Lc: Lanistes carinatus; Lv: Lanistes varicus; Mt: Melanoides tuberculata; pH; Water pH; Pw: Pila wernei; Sa: Segmentorbis angustus; Temp: Water temperature and TDS: Total dissolved salts).

Table 6

Monte Carlo test for evaluating the significance of environmental parameters in Damietta Governorate.

VariablesVariance explainedF-ratioP-value
Temp.0.2314.050.002
Ec0.042.260.06
pH0.010.730.596
Do00.360.832
TDS0.010.190.812

[i] P values were considered significant if ≤0.05

DOI: https://doi.org/10.2478/helm-2021-0026 | Journal eISSN: 1336-9083 | Journal ISSN: 0440-6605
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Language: English
Page range: 233 - 247
Submitted on: Jun 3, 2020
Accepted on: May 12, 2021
Published on: Sep 30, 2021
Published by: Slovak Academy of Sciences, Institute of Parasitology
In partnership with: Paradigm Publishing Services
Publication frequency: Volume open
Keywords:
Snails,
cercariae,
abundance,
seasonal,
physico-chemical,
Lanistes
Related subjects:
Life sciences,
Zoology,
Ecology,
Life sciences, other,
Medicine,
Clinical medicine,
Microbiology, virology and infection epidemiology

© 2021 M. E. El-Zeiny, A. M. Ghoneim, O. A. Abu Samak, A. A. Khidr, published by Slovak Academy of Sciences, Institute of Parasitology
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Volume 58 (2021): Issue 3 (September 2021)
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