Endobiotic and epibiotic mycobiota of loggerhead sea turtles (Caretta caretta)

master's thesis

• Title (croatian): EEndobiotska i epibiotska mikobiota glavatih želvi (Caretta caretta)
• Author: Borna Branimir Vuković
• Mentor: Sunčica Bosak (mentor)
• Mentor: Klara Filek (komentor)
• Committee member: Sunčica Bosak (predsjednik povjerenstva)
• Committee member: Marin Ježić (član povjerenstva)
• Committee member: Sandra Hudina (član povjerenstva)
• Committee member: Petar Kružić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2023-07-17, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

The loggerhead sea turtle (Caretta caretta) is a keystone species with an important ecological role
in marine ecosystems. They are the most widespread sea turtles in the Mediterranean Sea, and there
are ongoing conservation efforts aimed at preventing their population decline. These efforts can be
helped through loggerhead-associated microbiota studies by facilitating the diagnosis and
treatment of illnesses caused by pathogenic microorganisms. Despite that, such studies are scarce,
and comprehensive studies of fungal communities associated with loggerheads are non-existent.
The aim of this study was to describe the structure and composition of endobiotic and epibiotic
mycobiota of Mediterranean loggerheads. Microbial fungi were explored from the turtles’ cloacal
and tank water samples by analysing sequences of the ITS2 region of rDNA and carapace and skin
samples by analysing the V4 region of 18S rDNA. Cloacal and tank water mycobiota significantly
differed, but the cloacal mycobiota did not show significant alteration in relation to the turtles’ age
or hospitalisation length. Carapace and skin mycobiota were composed of the same dominant
divisions, but in different proportions. Comparison of endo-, epi- and environmental mycobiota
revealed marked differences in community composition. This study offers first insights into fungal
microbial communities associated with loggerheads, providing the basis for future research

Abstract (croatian)

Glavata želva (Caretta caretta) je ključna vrsta s iznimno važnom ekološkom ulogom u morskim
ekosustavima. U Sredozemnom moru je najzastupljenija vrsta morskih kornjača te se poduzimaju
značajni napori s ciljem očuvanja populacije. Ti su napori potpomognuti istraživanjima mikrobnih
zajednica povezanih sa želvama čime se pospješuje dijagnoza i liječenje bolesti uzrokovanih
patogenim mikroorganizmima. Unatoč tome, ovakva su istraživanja rijetka, dok sveobuhvatna
istraživanja zajednica gljiva (mikobiote) ovih kornjača ne postoje. Cilj ovog istraživanja je opisati
strukturu i sastav endobiotske i epibiotske mikobiote glavatih želvi iz Sredozemnog mora.
Zajednice gljiva su proučavane u uzorcima kloake kornjača i vode iz bazena analizom sekvenci
ITS2 regije rDNA, te uzorcima oklopa i kože kornjača analizom sekvenci V4 regije 18S rDNA.
Mikobiota kloake i bazenske vode se značajno razlikovala, no kloakalna mikobiota se nije značajno
mijenjala s obzirom na dob kornjača i duljinu rehabilitacijskog perioda. Mikobiota oklopa i kože
se sastojala od istih dominirajućih odjeljaka, no u različitim udjelima. Usporedba endo-, epi- i
okolišne mikobiote pokazala je znatne razlike u sastavu zajednica. Ovaj rad donosi prve uvide u
mikrobne zajednice gljiva asocirane s glavatim želvama te služi kao osnova za buduća istraživanja.

• Keywords: sea turtles; Fungi; Mediterranean Sea; ITS2; 18S
• Keywords (croatian): morske kornjače; Fungi; Sredozemno more; ITS2; 18S
• Language: english
• URN:NBN: urn:nbn:hr:217:852893
• Study programme: Title: Molecular Biology; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra molekularne biologije (magistar/magistra molekularne biologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Embargoed access; Embargo expiration date: 2025-07-17
• Created on: 2023-07-26 09:12:14