| Autor: |
Krzywda, Marta, Kaleli, Aydin, Solak, Cüneyt, Ljubešić, Zrinka, Bosak, Sunčica, Car, Ana, Witkowski, Andrzej |
| Přispěvatelé: |
Bosak, Sunčica, Ljubešić, Zrinka |
| Jazyk: |
angličtina |
| Rok vydání: |
2019 |
| Předmět: |
|
| DOI: |
10.1080/09670262.2019.1626628 |
| Popis: |
Loggerhead turtles (Caretta caretta) are primarily open-ocean animals that visit shallow coastal areas only for nesting. The geographic distribution and behavior of the species are strongly related to water temperature, food availability and oceanic currents. The turtle carapaces include a surface biofilm that serves as a habitat for epibiontic microorganisms such as bacteria and unicellular protists with diatoms being prominent in the assemblage. Research on diatom commensals on loggerhead turtle carapaces can provide interesting information on environments visited and general migration routes of the turtles. Mucilage stalks of the diatoms enable attachment to the carapace, but diatoms may also live inside mucilaginous tubes e.g. Parlibellus sp., or embed cells in mucilage matrix developed on the carapace surface. However, numerous diatoms simply inhabit the microbial EPS (extracellular polymeric substance) mixed with the mineral particles and form a distinct biofilm over the carapace. Here presented are results of a research on biofilm collected from Dalyan Beach region in Aegean Sea coast of SW Turkey during 2014 – 2018. The Dalyan Beach is considered one of the important Mediterranean nesting grounds for C. caretta. In 2016, a few pilot samples have been collected from C. caretta carapaces from Adriatic Sea (Croatia), the migration route for this species. Numerous diatoms, principally small pennate species, were isolated from biofilm into culture principally belonging in Navicula, Nitzschia, Diploneis, Halamphora, Entomoneis, Amphora and one centric Melosira sp. The true epibionts isolated in culture were few and involved stalked Achnanthes spp. and tube-dwelling Parlibellus spp. Identification of diatoms has principally been based on LM and SEM analyses of cleaned material. Diatoms in clonal cultures isolated from the C. caretta biofilm provided DNA that has been sequenced. A combined morphology (LM, SEM) and molecular markers (SSU, psbC, rbcL) establish a data base on a few dozens of taxa living in the C. caretta carapace biofilm. The spatial and temporal (sampling year) diversity of the diatom assemblages have been tested with multivariate analysis and multimetric ordination analysis (nonparametric multidimensional scaling – MDS). |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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