Species Composition And Distribution Of Leech (Annelida: Clitellata) In Zaria, Northern Guinea Savana, Nigeria

Abstract

Leeches are distributed worldwide and are found in aquatic and humid terrestrial environments. They play important roles in trophic systems as parasites, predators and prey and, in determining water quality and biodiversity of aquatic and wetland ecosystems. This study was carried out to determine the species composition and effects of physico-chemical parameters on the distribution of leeches in Zaria located within the northern guinea savanna zone of Nigeria. Leeches were collected from August - October 2019 in rice farms and the banks of a stream and a pond with the aid of forceps. The pH, temperature, electrical conductivity and total dissolved solids of each sampled location were taken in-situ using a Hanna Instrument. The average of each physico-chemical parameter was recorded as mean ± Standard Error. A total of 12 leeches belonging to 3 families were collected (Erpobdellidea: Erpobdella octoculata, Glossiphoniidae: Placobdella costata and Hirudinidae: Hirudo species). The species composition (3) which constitutes 25% and abundance (9) constitutes 75% of leeches were highest in the rice farm. Temperature, pH and electrical conductivity (EC) were relatively higher in the rice farm as compared with the stream and pond. However, the physico-chemical parameter did not affect the distribution and abundance of Erpobdella octoculata which was collected in all sampled locations. Species composition of leeches in Zaria was generally low due to reduced precipitation and vegetation type in the study area. Temperature, electrical conductivity, pH and total dissolved solids have effects on the distribution and abundance of Placobdella costata and Hirudo species. Intense survey of Leeches species composition is recommended in the study area.