Biodiversity of Earthworms with Special Reference to Tehsil Wazirabad, District Gujranwala, Punjab, Pakistan

Abstract

Earthworms are crucial soil invertebrates that are involved in the circulation of nutrients, humus formation, decomposition of organic matter and generation of soil texture. They play an important role as bioindicator of soil contamination. Objective: To investigate the biodiversity of earthworms in different habitats (Grassy lawns, croplands, marshy areas, ponds, edges of river and canals) of Tehsil Wazirabad, Punjab, Pakistan. Methods: A total number of four hundred and fifty (450) samples of earthworms were collected from above mentioned sites for a period of six months (March 2015 to August 2015), by hand sorting technique. Morphological details of all earthworm specimens collected from the designated areas were recorded and species were identified by using the systematic key. Results: During present investigation, six species; Pheretima posthuma, P. lignicola, P. morrisi, Microscolex dubis, Aporrectodea longa and Notoscolex sacutarius belonging to 4 genera and 2 families (Megascolecidae, Lumbricidae) were recorded. The distribution patterns of various earthworm species in the designated habitats shows that Pheretima posthuma is the most abundant species distributed in all sites; whereas, P. lignicola was least populated in the selected habitats. According to ecological grouping of reported earthworm species; Endogeic (50%) was the most dominant group followed by Epigeic (33%) and Anecic (17%). Conclusions: This study provided the base line data and much needed information about biodiversity of earthworms in Tehsil Wazirabad. This knowledge can be very useful in improving the soil conditions and agriculture gross production in investigated area.