Notes on Feeding Preferences of Some Cyprinids (Osteichthyes, Cyprinidae) in the Danube Downstream from Belgrade

Marija Egerić1, Dubravka Škraba1, Marija Ilić1, Vanja Marković1, Vera Nikolić2

 

1 Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar Despota Stefana 142, 11060 Belgrade, Serbia; E-mail: This e-mail address is being protected from spambots. You need JavaScript enabled to view it

2 Department of Zoology, Faculty of Biology, University of Belgrade, Studentski Trg 16, 11000 Belgrade, Serbia

 

 

Abstract

The aim of this paper is to analyze the diet of some cyprinids in Serbia. Fish were caught in the Danube near Belgrade in 2011. The gut contents of 27 specimens belonging to four species - Vimba vimba (Linnaeus, 1758), Abramis brama (Linnaeus 1758), Ballerus sapa (Pallas 1814) and silver bream Blicca bjoerkna(Linnaeus 1758), were analyzed. Gammarids (Amphipoda: Gammaridae) were found to be the most common and abundant prey utilized by all analyzed species. An especially high proportion of gammarids in the total diet composition was found in vimba bream. The Jacobs' preference index was used to better describe the diet of fish. Molluscs and oligochaetes, besides gammarids, are the dominant and most common macroinvertebrates in potamon-type rivers in Serbia. Based on our results those organisms are not preferred as a food of studied species.

Keywords: Jacobs' index, diet preferences, Abramis brama, Ballerus sapa, Vimba vimba, Blicca bjoerkna, Danube.

 

Introduction

European cyprinids are characterized by a variety of diets and feeding modes and have specialized representatives as zooplanktivores, herbivores, piscivores and benthivores (Lammens and Hoogenboezem, 1991). Although none of the cyprinids are strictly monophagous, many may feed on only one type of food organism, depending on its availability (Lammens and Hoogenboezem, 1991). As juveniles, they are planktivorous, eating various zooplankton taxa (Copepoda and Cladocera mostly), and most cyprinids can continue feeding on zooplankton until they are up to 15 cm in length or more (Biró et al, 1991; Lammens and Hoogenboezem, 1991).

Having a specialized feeding mechanism, involving a protrusible jaw, a branchiostegal pumping system and a pharyngeal mill, the majority of cyprinids are omnivores eating small aquatic insects, crustaceans, worms and detritus or often whatever is available (Bănărescu and Coad, 1991; Simonović, 2006).

Even when the principal food is invertebrates, cyprinids can supplement their diet with plant material. Piscivorous cyprinids are also comparatively rare, not unusually because of the lack of jaw teeth (Bănărescu and Coad, 1991). Although dominant fish in freshwater systems of Europe, little is known of cyprinid biology, including feeding/diet (Bănărescu and Coad, 1991).

The Danube is a river with the highest fish species richness (102 species ever reported) in Europe and cyprinids are the most numerous (Kovač, 2015). The Serbian stretch of the Danube is 588 km long, and mostly belongs to its middle part (Paunović et al, 2007).

Data regarding the biology, including feeding of cyprinids in Serbia/Serbian Danube are scarce. Krpo-Ćetković et al (2010) published a paper concerning the biology of Aspius aspius (Linnaeus, 1758), while Đikanović (2011) analyzed parasites and biology of the fish of the Belgrade region.

The present study aims to contribute to the knowledge regarding diet and feeding preferences of some cyprinid fish in the Serbian Danube.