The Role of Interspecific Competition in the Distribution of two Stream Dwelling Triclads, Crenobia alpina (Dana) and Polycelis felina (Dalyell), in North Wales

Publisher Website
Google Scholar
Abstract
The evidence for interspecific competition between C. alpina and P. felina (Tricladida) in the spring-fed streams of North Wales [United Kingdom] is examined. Circumstantial evidence is presented on the basis of distribution and abundance. Using serology it was demonstrated that their food requirements were very similar, providing a basis for competition. Evidence of intraspecific competition from the performance of field populations could not be obtained. A relative increase of the food resource by manipulating the population resulted in the apparent alleviation of intraspecific competition as determined by a biochemical method. Finally, a natural experiment presented itself in which a sudden decrease in a numerically superior population of P. felina resulted in a rapid increase in the numbers of a previously numerically inferior population of C. alpina. Collectively the several approaches suggested that interspecific competition was occurring between the 2 spp.

This publication has 1 reference indexed in Scilit: