Table of Contents
Advances in Zoology
Volume 2014 (2014), Article ID 678763, 7 pages
http://dx.doi.org/10.1155/2014/678763
Research Article

Seasonal Changes in Condition Factor and Weight-Length Relationship of Invasive Carassius gibelio (Bloch, 1782) from Leszczynskie Lakeland, Poland

1Dipartimento di Matematica, Università degli Studi di Bari, 4 Via Orabona, 70125 Bari, Italy
2Department of Fisheries Management in Open Waters, West Pomeranian University of Technology in Szczecin, 4 Ulica Krolewicza, 71-550 Szczecin, Poland
3Department of Aquatic Sozology, West Pomeranian University of Technology in Szczecin, 4 Ulica Krolewicza, 71-550 Szczecin, Poland

Received 30 July 2014; Revised 3 October 2014; Accepted 10 November 2014; Published 23 November 2014

Academic Editor: Raine Kortet

Copyright © 2014 Marcello De Giosa et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Samples of invasive cyprinid fish, the Prussian carp (Carassius gibelio), were collected by fyke nets in Leszczynskie Lakeland (Poland) during the summer and autumn, 2010, and during the spring, 2011. All captured fish were females. For each fish, the total weight () and the standard length () were measured and Fulton’s condition factor was computed. Graphical investigation and the Mann-Whitney-Wilcoxon test showed statistically significant location shift of the distribution from summer to autumn (upward) and from autumn to spring (downward). Relationship between total weight and standard length was described with the mean growth curve . Seasonal parameters ( and ) were estimated with a nonlinear regression approach, that is, numerical optimization methods. Growth was allometric in summer and autumn and isometric in spring. The differences between summer and autumn growth curves and between autumn and spring growth curves were statistically significant. The seasonality exhibited by the condition factor and the growth curve may be due to different spawning, breeding, and feeding activity in the different seasons and to variable environmental conditions.