Ritterbusch, D. & J. Bohlen

On the ecology of spined loach in Lake Müggelsee

Folia Zoologica 49 Suppl. 1: 187-192

Folia Zoologica 49 Suppl. 1: 187-192 (2000)

On the ecology of spined loach from Lake Müggelsee

RITTERBUSCH D. & J. BOHLEN

Abstract

The growth, density and diet of a diploid-polyploid-complex of spined loach were investigated. The recruitment of juveniles was irregular due to the dependence of reproduction on filamentous algae. If compared to literature data, growth was rather fast but varied between the years. The lack of young age classes possibly led to differences in density dependent factors influencing the growth. After appearance in spring, the fish were stationary with only single mobile individuals. In autumn the animals disappeared from the shallow shore area. The distribution at the shore was very irregular during the stationary period. The fish fed exclusively upon benthic organisms and showed a special size spectrum of ingested items. No differences between the genetic forms concerning the investigated aspects were found. This indicates a high niche overlap between the levels of ploidy.

Key words: growth, density, diet, diploid-polyploid-complex, competition, Cobitis