Motile homes: a comparison of the spatial distribution of epibiont communities on Mediterranean sea turtles

Abstract

Understanding the ecological roles performed by an individual species requires knowledge from a wide range of disciplines; here we analyze the epibiont–host relationship found in marine turtles. During the study we recorded five new species of sea turtle epibiont: Laomedea flexuosa, Caprella fretensis, Hyale nilssoni, Hyale schmidti, Parasinelobus chevreuxi; as part of a total of nine zoological epibionts present on 35 female green turtles (Chelonia mydas) and 100 loggerhead turtles (Caretta caretta) nesting in Cyprus. The two most commonly occurring epibionts were acorn barnacles Chelonibia testudinaria and Chelonibia caretta, with larger specimens of both species recorded on loggerhead turtles. We analyzed the spatial distribution of these two barnacle species upon the carapaces of their hosts. Specimens of C. testudinaria situated on the anterior half of the carapace were larger than those located at the posterior. A significantly larger proportion of loggerhead turtles (52.5%) hosted epibionts in comparison to green turtles (30.3%). All non-barnacle epibionts were associated with either posterior algal mats or carapace scars.

Keywords:

• epibiont
• spatial distribution
• barnacles
• Caretta caretta
• Chelonia mydas

Acknowledgements

This work is part of the doctoral thesis of WJF, begun at the University of Wales, Swansea, and completed at the University of Exeter, part-funded by a University Scholarship. The authors thank all the student volunteers who assisted with fieldwork as part of the Marine Turtle Conservation Project 1999–2004, a collaboration between the Marine Turtle Research Group, The Society for the Protection of Turtles in North Cyprus and the Department of Environmental Protection. Sponsors included British Chelonia Group, British High Commission, and the Royal Society. The authors would also like to thank Dr P.J. Hayward for his confirmation of the non-barnacle species and Mike Frick for his advice and confirmation of the five new turtle epibiont records. BJG and ACB were funded by grants from the Darwin Initiative, European Social Fund and NERC. This manuscript was improved by comments from reviewers.

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