Publication Abstract

Life history traits of introduced Iberian pumpkinseed (Lepomis gibbosus) relative to native populations: Can differences explain colonization success?

Life history traits of introduced Iberian pumpkinseed (Lepomis gibbosus) relative to native populations: Can differences explain colonization success? 

M.G. Fox, A. Vila-Gispert & G.H. Copp

To assess the colonization success of pumpkinseed on the Iberian Peninsula, we compare life history attributes of pumpkinseed populations from Spanish water bodies to populations in the northern and southern parts of its native range, as well as to those of English water bodies where introduced populations have shown minimal natural range expansion. Discriminate Function analysis using five population characteristics (mean age at maturity, mean length at maturity, gonadosomatic index (GSI), mean length at age 2 as an indication of juvenile growth rate, and relative body condition) strongly differentiated populations from the four regional study areas. Spanish populations were early maturing, showed moderate juvenile growth rate and length at maturity, and high gonadosomatic index relative to the other population groups. Spanish populations matured significantly earlier than Canadian and English populations, but not southern U.S. populations. However, Spanish populations had a significantly higher GSI than southern U.S. populations, suggesting greater reproductive output. Considering these differences in the context of the triangular life-history strategy model of Winemiller and Rose (1992) the pumpkinseed exhibits “equilibrium” life history traits that have made other non-native fishes successful invaders in areas where habitat alteration has resulted in more predictable discharge regimes and water levels, yet populations in Iberia appear to have achieved their success by adopting a more “opportunistic” life history strategy than their native counterparts. High levels of life history plasticity appear to contribute to the success of this species on the Iberian Peninsula.

Reference:
Fox, M.G., Vila-Gispert, A. & Copp, G.H. 2007. Life history traits of introduced Iberian pumpkinseed (Lepomis gibbosus) relative to native populations: Can differences explain colonization success? Journal of Fish Biology 71 (Supplement D), 56–69.

M.G. Fox, A. Vila-Gispert & G.H. Copp*

Journal of Fish Biology 71 (Supplement D), 56–69.