Sastav prehrane štuke (Esox lucius Linnaeus, 1758) unesene u rijeku Vrljiku

master's thesis

• Title (english): Diet composition of pike (Esox lucius Linnaeus, 1758) introduced in Vrljika river
• Author: Dajana Majnarić
• Mentor: Daniel Matulić (mentor)
• Mentor: Goran Jakšić (komentor)
• Committee member: Daniel Matulić (predsjednik povjerenstva)
• Committee member: Goran Jakšić (član povjerenstva)
• Committee member: Tea Tomljanovic (član povjerenstva)
• Committee member: Ana Gavrilović (član povjerenstva)
• Granter: University of Zagreb; Faculty of Agriculture; (Fisheries, Beekeeping, Game Management and Special Zoology); Zagreb
• Defense date and country: 2024-09-19, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Agronomy

Abstract

Cilj rada bio je analizirati prirodnu prehranu štuke (Esox lucius) naturalizirane u gornjem toku
rijeke Vrljike. Prikupljeno je 38 jedinki štuke u veljači 2020. godine. Svakoj jedinki izdvojeno
je probavilo rezanjem kod jednjaka i analnog otvora te su pronađene svojte determinirane
do razine razreda i reda, a neke i do vrste. Kako bi dobili uvid u kvalitativni i kvantitativni
sastav prehrane štuke u Vrljici, izračunat je postotak brojnosti (%N), postotak učestalosti
pojavljivanja (%F), postotak mase (%W) i indeks relativne važnosti (%IRI). Od ukupno 38
analiziranih jedinki, kod njih 17 (44,74%) utvrđeno je puno, a kod 21 (55,26%) prazno
probavilo. Jedinke manje od 50 cm ukupne duljine tijela preferiraju ribu kao svoj plijen, dok
kod jedinki ukupne duljine tijela manje od 50 cm najveću zastupljenost u prehrani imaju
rakušci iz reda Amphipoda i jednakonošci iz reda Isopoda. U prehrani štuka iz Vrljike
determinirane su tri vrste riba, od kojih su dvije endemske basak (Rutilus basak) i imotska
gaovica (Delminichthys adspersus) i štuka (Esox lucius) s čime se potvrdio kanibalizam kod
štuke. Rezultati izračuna navedenih metoda prikazuju da štuka preferira drugačiji plijen
ovisno o njezinoj dužini tijela.

Abstract (english)

The aim of this study was to analyze the natural food diet composition of pike introduced
and naturalized in the upper course of the Vrljika River. In February 2020., 38 individuals of
pike were collected. Digestion was isolated from each individual by cutting the esophagus
and anal opening. The individuals analyzed were determined to the class and level of order.
Out of a total of 38 analyzed pike, 17 (44,74%) of them had a full and 21 (55,26%) had an
empty stomach. In order to gain an insight into the qualitative and quantitative composition
of the diet of pike in Vrljika, the percentage of abundance (%N), the percentage of frequency
of occurrence (%F), the percentage of mass (%W) and the relative importance index (%IRI)
were calculated. The calculation results of the mentioned methods show that pike prefers
different prey depending on the body length. Pike with a total body length of less than 50 cm
prefer fish as their prey, while for pike with total body length of less than 50 cm, crustaceans
from the order Amphipoda and Isopoda are the most important in their diet. Three types of
fish have been found in the diet of pike in Vrljika river, two of them are endemic; basak
(Rutilus basak) and spotted minnow (Delminichthys adspersus), and pike (Esox lucius) which
confirmed cannibalism in pike.

• Keywords: Esox lucius; štuka; Vrljika; prirodna prehrana; endemske vrste
• Keywords (english): Esox lucius; pike; Vrljika; endemic species; natural diet
• Language: croatian
• URN:NBN: urn:nbn:hr:204:659695
• Study programme: Title: Fisheries and Game Management; Study programme type: university; Study level: graduate; Academic / professional title: magistar/ magistra inženjer/inženjerka ribarstva i lovstva (magistar/ magistra inženjer/inženjerka ribarstva i lovstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2024-10-01 08:48:07