The allochthonous pumpkin seed, (Lepomis gibbosus, L.1758) is the most abundant species (about half of the total fish 

abundance) in Bara Lake, Croatia. Pumpkin seeds caught by electro fishing were subjected to the determination of length-

weight relationship, length-length relationship, morphometric and meristic characters, age structure and growth performance. 

The length-weight relationship showed a significant linear relationship (P = 0.00). Similarly, the total and standard length 

also showed a highly significant linear relationship (P < 0.05).The growth model for the individuals based on length-weight 

relationship was determined as W = 0.013L3.14. Three age groups were observed (1 + to 3 + ) in the age structure among which 

more than 60% of the fish belonged to the 2 + groups. The asymptotic length (L∞) found in the present study was smaller 

(8.45cm) than those reported from other European countries. The estimated value of growth coefficient was 0.723 and overall 

growth performance, ǿ was 1.71derived using Von Bertalanffy growth parameters. The pumpkinseed population in the present 

study was characterized by higher growth and smaller age structure compared with other European pumpkinseed populations 

suggesting the recent invasion of pumpkinseed population in Bara Lake