Original scientific paper
Growth dynamics of the chub fish in the river Sava
Dobrila Habeković
; Univrsity of Zagreb, Faculty of Agriculture, Svetošimunska 25, 10 000 Zagreb
Ivica Aničić
; Univrsity of Zagreb, Faculty of Agriculture, Svetošimunska 25, 10 000 Zagreb
Roman Safner
; Univrsity of Zagreb, Faculty of Agriculture, Svetošimunska 25, 10 000 Zagreb
Abstract
Investigations on the chub fish (Leuciscus c. cephalus L. 1578) and its growth dynamics were carried out in the summer of 1991, and during the spring, summer and autumn of 1992 in the river Sava downstream from Podsused (near Zagreb) on 2 locations (area of Medsava).
It was determined that the chub is constantly inhabiting this area in numbers which are within the values determined in previous investigations (numerousness 22-30%, ichtyomass 45-51%).
The results of investigations are presented in Tables 1-3 and in Figures 1-7. The age structure of the chub is between 0 to 4+, with a dominance of younger age groups.
Length and height relations and feeding coefficients of the chub gradually increase with age, while the seasonal differences are minimal.
A significantly slower growth rate in length was determined for the chub 3+ and 4+, while the weight growth has an already slower rate from age 1+, then particularly slow at age 2+, 3+ and 4+ in relation to the results of previous investigations.
Deteriorating living conditions over the past few years in the river Sava is the cause of the slower growth rate of the chub, which is especially emphasized in the dynamics of weight growth.
Keywords
Hrčak ID:
77053
URI
Publication date:
23.9.1993.
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