Utjecaj invazivnih stranih vrsta rakušaca (Crustacea, Amphipoda) na makrozoobentos i razgradnju listinca u velikim rijekama

doctoral thesis

• Title (english): The impact of invasive alien amphipods (Crustacea, Amphipoda) on macroinvertebrate community and leaf litter decomposition in large rivers
• Author: Tomislav Kralj
• Mentor: Damir Valić (mentor)
• Mentor: Krešimir Žganec (komentor)
• Committee member: Zlatko Mihaljević (predsjednik povjerenstva)
• Committee member: Jasna Lajtner (član povjerenstva)
• Committee member: Marina Vilenica (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2023, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology
• Universal decimal classification (UDC): 57 - Biological sciences. Physical anthropology. Biodiversity

Abstract

Invazivne vrste su među najvažnijim uzrocima smanjivanja bioraznolikosti u slatkovodnim
ekosustavima. Rakovi iz nadreda Peracarida (redovi Amphipoda, Isopoda i Mysida) su skupina s
brojnim invazivnim vrstama. Prijašnjim istraživanjima, u velikim rijekama Hrvatske (Dunav, Sava,
Drava, Mura) zabilježeno je 13 stranih vrsta perakaridnih rakova, no malo se zna o njihovom
utjecaju na makrozoobentos, odnosu s abiotičkim čimbenicima te utjecaju na razgradnju listinca.
Ciljevi ovog rada obuhvatili su doprinos invazivnih stranih vrsta rakušaca biokontaminaciji
makrozoobentosa, njihov odnos s abiotičkim čimbenicima vode te utjecaj invazivnog rakušca
Dikerogammarus villosus na autohtone perakaridne rakove i razgradnju listinca. Strani perakaridni
rakovi dominiraju brojnošću jedinki te značajno doprinose biokontaminaciji istraživanih rijeka.
Iako se smatra da su otporni na onečišćenje vode, veće gustoće ovih rakova zabilježene su na
postajama s manjim onečišćenjem i višim vrijednostima bioloških metrika. Za utjecaj rakušca D.
villosus na razgradnju listinca dobiveni su oprečni rezultati koji pokazuju da njegov utjecaj ovisi o
okolnostima i sastavu zajednica usitnjivača. Uzvodno širenje ove vrste praćeno je smanjenjem
gustoće autohtonih perakaridnih rakova, osobito na šljunkovito-valutičastom supstratu pri čemu
nije zabilježen negativan utjecaj na fekunditet autohtonih rakušaca.

Abstract (english)

Invasive species highly contribute to freshwater biodiversity loss. Peracarid crustaceans, the orders
Amphipoda, Isopoda, and Mysida consist of many invasive alien species. In Croatian large rivers
(Danube, Sava, Drava, Mura), 13 alien peracarid species have been recorded in previous studies,
yet little is known about their impact on aquatic macroinvertebrate communities, their relationship
with physico-chemical water parameters, and their influence on leaf litter decomposition. The
objectives of this work were to investigate their contribution to the biocontamination of
macrozoobenthos in large rivers, their relationship with abiotic factors, and the effects of the
invasive amphipod Dikerogammarus villosus on native peracarids and leaf litter decomposition.
Alien peracarids were abundant in studied rivers, contributing significantly to the biocontamination
of the rivers studied. Although assumed to be resistant to pollution, they exhibited higher
population densities at sites with higher values of biological metrics with lower level of pollution.
Conflicting results were obtained regarding the effects of D. villosus on decomposition rates of leaf
litter, as they depended on the circumstances and abundance of native shredders. The invasion of
D. villosus was accompanied by a decrease in population densities of native peracarids, especially
on stony substrates, while no negative effects of this invasive amphipod species on fecundity of
native amphipods were detected.

• Keywords: perakaridni rakovi; invazivni rakušci; biokontaminacija; fizikalno-kemijski čimbenici vode; razgradnja listinca; mikrodistribucija; fekunditet
• Keywords (english): Peracarida; invasive amphipods; biocontamination; physico-chemical water properties; leaf litter decomposition; microdistribution; fecundity
• Language: croatian
• URN:NBN: urn:nbn:hr:217:535726
• Promotion: 2023
• Study programme: Title: Biology; Study programme type: university; Study level: postgraduate; Academic / professional title: doktor/doktorica znanosti, područje prirodnih znanosti, polje biologija (doktor/doktorica znanosti, područje prirodnih znanosti, polje biologija)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Embargoed access; Embargo expiration date: 2025-05-04
• Created on: 2023-05-31 10:10:15