Age, growth and reproductive properties of an invasive species carassius gibelio (Bloch, 1782) (Cyprinidae) in the Ikizcetepeler Dam Lake (Balikesir), Turkey

Abstract

Background and Purpose: The Prussian carp Carassius gibelio is well known as a hazardous fish species for native fish communities. Ikizcetepeler Dam Lake inhabits some fish species as Cyprinus carpio, Leuciscus cephalus, and Barbus species. The dam lake has major economic importance to the area for both fisheries and drinking water. The reason to select C. gibelio was due to the dominant species in stagnant and slow running waters and possible harmful interactions with native species.

Materials and methods: A total of 480 specimens of C. gibelio were monthly collected by gill nets during a 1-year period from Ikizcetepeler Dam Lake. Age was determined from scales. Length-weight relationships, von Bertalanffy equation were used to estimated for growth. Sex were determined by macroscopic observation of gonads. Spawning period of this species was determined according to gonado-somatic index (%).

Results: Females and males reached a maximum age groups of VI. Total length was 23.6-31.3 cm in females and 23.0-31.4 cm in males. The male and female ratio was 1:3.52 (M:F) in the favor of females. The Von Bertalanffy growth equations (in length) were found as L-t = 34.89.(1-e(-0.11(t+760))), L-t = 32.09(1-e(-0.23(t+5.83))) for females and males, respectively. The estimated b values were given as 2.886 and 2.981 for females and males, respectively (b<3). The condition of the fish increased during early summer. Spawning period of this species occured between April and July.

Conclusions: With a comparison of the relevant literature, the studied Prussian carp population was characterized by a shorter life span and more rapid