On Caretta caretta’s shell: first spatial analysis of micro- and macro-epibionts on the Mediterranean loggerhead sea turtle carapace

ABSTRACT

The loggerhead sea turtle, Caretta caretta (Linnaeus, 1758), is the most common sea turtle species in the Mediterranean Sea, where it can experience severe anthropogenic impacts. Although C. caretta is known to host more than 200 epibiotic taxa (crustaceans, algae and cyanobacteria), no reports have included a detailed evaluation of the microbial community of its carapace scutes. Thus, this study aimed to determine the diversity and composition of the visible and invisible communities on the carapace scutes of wild loggerhead turtles from the Aeolian Archipelago (Southern Tyrrhenian Sea, Italy) by using a combined approach of morphological/spatial examination and molecular analyses. Altogether, our results displayed a higher abundance of crustaceans, macroalgae and Proteobacteria on the posterior carapace scutes, while Firmicutes were more abundant on the anterior scutes. For the first time, this study showed the complexity of the microbial (invisible) and visible epibionts of the loggerhead sea turtles from the Mediterranean Sea and suggests the importance of including evaluation of the microbial components when studying epibiont communities.

KEYWORDS:

• Caretta caretta
• cyanobacteria
• firmicutes
• proteobacteria
• Kilonelliaceae
• biofilm

Acknowledgements

We thank Dr Chiara Bruno for her support during turtle hospitalization and sampling at Filicudi Wildlife Conservation First Aid. The authors wish to thank Loretta Lattanzi and Paolo Tomassetti for crustacean identification, Chiara Conte and Nicoletta Perini for bioinformatics analyses. We wish to thank Filicudi Wildlife Conservation for Logistic and in-kind support.

Disclosure statement

No potential conflict of interest was reported by the authors.

Availability of data and material

Regarding bacterial sequence data, the complete set of raw sequences obtained in this study was deposited in GenBank under the study accession BioProject ID no. PRJNA681485.

Author contributions

Conceptualization and Methodology: Monica Blasi, Luciana Migliore; Formal analysis and investigation: Alice Rotini, Tiziano Bacci, Monica Targusi, Giusy Bonanno Ferraro, Luca Vecchioni; Writing – original draft preparation: Rosa Alduina, Alice Rotini, Tiziano Bacci, Monica Targusi, Giusy Bonanno Ferraro; Writing – review and editing: All authors; Resources: Monica Blasi, Luciana Migliore; Supervision: Monica Blasi, Luciana Migliore, Rosa Alduina. All authors read and approved the final manuscript.

Ethics approval:

Sampling was carried out following the regulations of the International Council for Laboratory Animal Science Ethical Guidelines and was authorized by the Italian Ministry of Environment (PROT. N° 0001735, 02-02-2010; renewal: PROT N° 0006876, 25-01-2013).

Consent to participate: not applicable.

Consent for publication: not applicable.

Additional information

Funding

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.