Growth and Life History Traits of a Highly Exploited Population of Non-Native Gibel carp, Carassius gibelio from a Large Eutrophic Lake (Lake Uluabat, NW Turkey): is Reproduction the Key Factor for Establishment Success?

Abstract

To assess establishment success of a heavily exploited population of non-native gibel carp Carassius gibelio, biological traits and population structure of the species from a large eutrophic lake (Lake Uluabat, Turkey) were investigated from June 2009 to May 2010 and attributes were compared with the published information from the introduced and native range. Commercial harvesting of gibel carp did not seem to affect population size and viability of gibe! carp in Lake Uluabat but it had one of the slowest growth rate represented by twelve age groups, and its life span was one of the longest recorded for the populations both in its natural and introduced areas. The reproductive season lasted from March to early May. Size at maturity was earlier and relative fecundity was higher than those in the introduced range. Higher investment in reproduction displayed by earlier maturation, higher relative fecundity and gonadosomatic index with gynogenetic spawning in Lake Uluabat is likely to be the key factor for establishment success of gibel carp.