Rasprostranjenost i populacijske značajke invazivne vrste raka Pacifastacus leniusculus (Dana, 1852) i autohtone vrste raka Astacus astacus (Linné, 1758) na području Međimurja

master's thesis

• Title (english): Distribution and population characteristics of invasive crayfish species Pacifastacus leniusculus (Dana, 1852) and native crayfish species Astacus astacus (Linné, 1758) in Međimurje
• Author: Sara Janković
• Mentor: Jasna Lajtner (mentor)
• Committee member: Jasna Lajtner (predsjednik povjerenstva)
• Committee member: Renata Šoštarić (član povjerenstva)
• Committee member: Ana Galov (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2010-12-15, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

Cilj ovog rada bio je ustanoviti gustoću i značajke populacije strane invazivne vrste signalnog raka u rijeci Muri te trenutačnu rasprostranjenost i značajke populacije autohtone vrste riječnog raka na području Međimurja. Značajke populacije invazivnih rakova istraživane su na dvije postaje, dok je rasprostranjenost populacija autohtone vrste istražena na ukupno 53 lokacije, upotrebom LiNi vrša. Procijenjena gustoća populacije signalnog raka u rijeci Muri pripada srednjoj zabilježenoj gustoći ove invazivne vrste u Europi. Populacije riječnog raka trenutno su prisutne na malom broju istraženih lokacija (17 %), većinom u šljunčarama (66 %), u koje su unesene od strane čovjeka. Analize uzrasno-spolne strukture pokazale su kako su istražene populacije obje vrste relativno stabilne. Povećan postotak tjelesnih oštećenja u populacijama riječnog raka (42 % životinja) pripisan je nepovoljnosti šljunčara kao staništa za ovu vrstu. Jedinke riječnog raka bile su u prosjeku veće i teže od jedinki signalnog raka, što pokazuje kako nedavno uspostavljena populacija signalnog raka u rijeci Muri još nije dosegla svoju maksimalnu veličinu i gustoću.

Abstract (english)

The aim of this work was to examine the population size and characteristics of the invasive signal crayfish in the Mura River and the current distribution and population characteristics of the indigenous noble crayfish populations in Međimurje. The signal crayfish population was examined at two locations, whereas the noble crayfish populations were examined at 53 locations, with baited LiNi traps. The estimated density of the signal crayfish in the Mura River belongs to mean values recorded for this species in Europe. The distribution of the noble crayfish populations in MeĎimurje is narrow, since crayfish were present in only 17 % of the examined locations, mainly in gravel pits (66 %) where they were introduced anthropogenically. The analysis of size and gender showed that populations of both species were relatively stable. Since gravel pits are unfavourable habitats for noble crayfish, increased proportion of body injuries (42 %) was recorded in these populations. Noble crayfish individuals were on average larger and heavier than signal crayfish, which indicates that the recently established signal crayfish population in the Mura River did not reach its maximum size and density at the time.

• Keywords: riječni rak; signalni rak; gustoća populacije; rasprostranjenost; uzrasno-spolna struktura populacija
• Keywords (english): noble crayfish; signal crayfish; population size; distribution; size and gender structure of populations
• Language: croatian
• URN:NBN: urn:nbn:hr:217:300216
• Study programme: Title: Ecology; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra ekologije i zaštite prirode (magistar/magistra ekologije i zaštite prirode)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-05-03 12:51:14