Author: K. Nasira, S. Shamim and F. Shahina
Publishing Date: 2016
Volume 34 Issue 1
Fresh water is natural source of water for drinking; domestic and industrial use which available primarily from melting of ice, rivers, streams ponds and ground. In Pakistan Indus River and its tributaries are the major sources of fresh water. Fresh water is clear from pollutants in upcountry, but as it flows downstream it becomes more pollutant. In the present study nematodes were selected as bio-indicators for these pollutants at eight localities of Sindh, which are Malir, Karachi; Kalri (Keenjhar) Lake, Thatta; Karachi Canal and Al-Manzar at River Indus near Jamshoro; Goth Detha Hyderabad; Khesana Mori near Tandojam; Mirpurkhas and Jamesabad (Kot Ghulam Mohammad). Samples from different sources of freshwater viz., river, lake, canal, tube well, pond and irrigation water chennal were examined for the prevalence of nematodes with an aim to disseminate the knowledge of fresh water nematodes as indicators in environmental monitoring. Detailed sample analysis revealed the presence of forty nematode species including three new species viz., Bathyeurystomina minima Nasira, Shahina & Shamim, 2014, Belbolla longispiculata Nasira, Shahina & Shamim, 2014 and Metoncholaimus siddiqii Shahina, Nasira & Shamim, 2015 while six species were reported as new records of Pakistan. These nematode species belong to 36 genera, 27 families and seven orders. Frequency of occurrence and distribution of nematode species varied from site to site. The overall occurrence (%) of fresh water nematode samples ranged from 3.22-32.25% at different sites. The highest number of positive samples was found at Malir, Karachi (32.25%) and the lowest was at Khesana Mori, Tandojam (3.22%). Free-living soil nematodes have more occurrences (55%) as compared to other group of nematodes. The occurrence (%) of nematode species at each site also varied considerably and ranged between 0.86-4.47% at Malir, Karachi; 1.93-5.79% at Kalri Lake, Thatta; 1.15-5.98% at Karachi Canal, Jamshoro; 1.58-5.93% at Al Manzar, Jamshoro; 24-8.11% at Detha, Hyderabad; 2.33-8.84% at Khesana Mori, Tandojam; 1.71-5.57% at Mirpurkhas and 2.38-8.95% at Jamesabad. A similarity matrix based on the proportion of shared nematode community was used to establish the level of relatedness between the different sites. Two surveyed sites Karachi Canal and Al-Manzar at River Indus, Jamshoro were close to each other for the presence of fresh water nematodes as compared to other localities whereas, similarity for localities and nematode species ranged from 0.458 to 0.7 and 0.45 to 1.0, respectively. Ecological indices viz., Shannon’s index, species richness, evenness and maturity index were used for monitoring environmental conditions of each sampling site. The two indices viz., diversity index and maturity index were lowest at sites, Jamesabad and Khesana Mori which can be considered as indications of stress at these sites.
Key word: Fresh water nematodes, diversity, Sindh, Pakistan