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THE NUTRITION OF A PIKEPERCH, Stizostedion lucioperca Linnaeus, 1758 in THE RIVER NERETVA
S. Trožić-Borovac
R. Škrijelj
Sažetak
The analysis of content of a pikeperch gastro–intestine system was done on the basis of examination of contents of gastro–intestine systems of 27 specimens captured in the accumulations of the river Neretva system. The fish capture was done using the nets set by the members of Ichthyology and Fishing Center at the Faculty of Science Sarajevo, in the period between 17. 07 — 24. 09. 2002. The dissection and fixation of gastro–intestine systems using the 4 % formaldehyde were done on the terrain. The examination of their contents was done in the laboratory of the Faculty of Science Sarajevo. The appearance of a pikeperch in the river Neretva system is result of an accident introduction in the lake Rama (Š k r i j e l j, 1995; Š k r i j e l j and Ma š o v i ć, 2001). The analysis results of the contents of a pikeperch gastrointestine system have indicated very various way of its nutrition caused by capacity of a water ecosystem and a specimen size. Its tendency to the nutrition with the other fish species is expressive in the lakes with the bigger competition with the other fish species and its tendency to cannibalism is expressive in the hydro–accumulations (Salakovac and Mostar). The cannibalism has characterized a pikeperch specimens larger than 30 cm. The specimens in the lake Grabovica (4), shorter than 30 cm, ate the specimens of the zoobenthos settlement. The algae are registered in stomach of one specimen. The survival of important autochthonous species of salmonoids and cyprinids has been endangered because of the established expressive greed of a pikeperch (the larger size specimens). This fact has caused larger negative ecological changes in the central water current of the river Neretva system. These conditions require the measures of control of a pikeperch population density and introduction in general. Comparison of the nutrition of this fish species with the others in the river Neretva accumulations (K a č a n s k i et al., 1976; T r o ž i ć – B o r o v a c, 2002a), it could be concluded that a pikeperch has no competitor. The other fish species have fed on the invertebrates and plants of benthos, accept a rare lake trout Salmo trutta m. lacustris Linnaeus, 1758 specimens which have shown tendency to the greedy way of the nutrition.
This paper is the contribution to the knowledge of a pikeperch nutrition in the river Neretva accumulations that is, beside the reproduction, the important character of population growth control of this greedy animal, and in the aim of the survival of the autochthonous ichthyopopulations in the river Neretva system.
Ključne riječi
pikeperch nutrition; river Neretva; hydro–accumulations
Hrčak ID:
18898
URI
Datum izdavanja:
30.6.2007.
Posjeta: 2.226 *