Epibiont communities of loggerhead marine turtles (Caretta caretta) in the western Mediterranean: influence of geographic and ecological factors

Abstract

This study reports for the first time on the whole epibiont fauna of loggerhead marine turtles, Caretta caretta, in the western Mediterranean, analysing the factors that account for the predictability and composition of the assemblage. A total of 104 loggerhead turtles stranded along the coasts of eastern Spain during 1995-2006 were surveyed for epibionts. A total of 39 epibiont taxa were identified, three of them being new records for loggerhead turtles: Bittium sp., Idotea metallica and Jassa sp. The assemblage was composed of a group of 27 facultative taxa that use turtles as any inanimate buoyant substrate, and 12 taxa that have developed more specific associations to marine turtles, including six species that occur in marine turtles exclusively, two that dwell also on other hosts, and four that can also survive as free-living forms but have developed a strong association with marine turtles. Hierarchical clustering and Similarity Profile Analysis based on the occurrence of 166 epibiont taxa from nine available surveys indicated that the epibiont assemblages from loggerhead turtles in the western Mediterranean (WM) are similar to those from Central Mediterranean (CM), but significantly different from turtles surveyed in the eastern Mediterranean and the Atlantic. The subset of epibionts occurring on WM and CM turtles is defined by a combination of geographic factors (exclusive Mediterranean epibiont taxa) and ecological factors (relative absence of littoralbenthic taxa). Loggerhead turtles from WM and CM apparently exploit both pelagic and benthic habitats in similar fashion, representing a homogeneous unit for epibiont recruitment. R. (2005) Size at male maturity, sexing methods and adult sex ratio in loggerhead turtles (Caretta caretta) from Italian waters investigated through tail measurements. . (2014) Deconstructing an assemblage of "turtle" barnacles: species assignments and fickle fidelity in Chelonibia. Marine Biology 161, 45-59. and Zibrowius H. (1971) Les espèces Méditerranéennes du genre Hydroides (Polychaeta Serpulidae): remarques sur le prétendu polymorphisme de Hydroides uncinata. Tethys 2, 691-746.

Description, systematics and ecology of a new tanaidacean (Crustacea, Peracarida) species from mediterranean fish farms

“…Hexapleomera robusta, previously reported from turtles in the Mediterranean [12][13][14][15], has been also observed associated to fish farm fouling in this study. According to [15], H. robusta may be found associated to the algae Polysiphonia sp, which is also part of fish farms fouling [11]. It is feasible that H. bultidactyla will be found in other natural habitats containing similar algae or hydroids species than those found in fish farm fouling.…”

“…Specifically, tanaidaceans represent between 0.03 and 15.9 % of the mobile epifauna associated with fish farms fouling in the Mediterranean Sea, being the third group in importance after amphipods and polychaetes [11]. Hexapleomera robusta, previously reported from turtles in the Mediterranean [12][13][14][15], has been also observed associated to fish farm fouling in this study. According to [15], H. robusta may be found associated to the algae Polysiphonia sp, which is also part of fish farms fouling [11].…”

Epibiontes en juveniles de tortugas carey Eretmochelys imbricata varadas en la costa del Departamento de Rocha, Uruguay

“…La importancia del conocimiento de los epibiontes radica en que pueden proporcionar información indirecta acerca de aspectos biológicos de los quelonios que son difíciles de elucidar, tales como sus rutas migratorias y determinados aspectos de su ciclo de vida (Casale et al 2012, Domènech et al 2014. Recopilar información sobre los epibiontes de tortugas marinas ayuda a conocer la dinámica de las diferentes poblaciones; la cantidad y especies de epibiontes pueden dar indicios de las características del área de alimentación y tiempo de permanencia en las mismas, además del estado de salud de las tortugas marinas.…”

“…Se define como epibionte cualquier organismo que vive y crece sobre otro ser vivo, siendo el basibionte el organismo que funciona como sustrato en esta asociación (Liria 2011). Existe una gran cantidad de organismos capaces de colonizar la superficie de las tortugas marinas (Schärer 2003, Liria 2011, ya que éstas ofrecen un sustrato para el asentamiento que es temporalmente estable y adecuado a la escala de duración del ciclo de vida de los epibiontes (Domènech et al 2014). La relación epibionte-tortuga puede resultar muy estrecha y compleja e incluso específica de especie; existen organismos que sólo se encuentran asociados a tortugas marinas (Hernández-Vázquez & Valadez-González 1998).…”

To Swim or Not to Swim: Potential Transmission of Balaenophilus manatorum (Copepoda: Harpacticoida) in Marine Turtles

“…A second species, B . manatorum , occurs on the skin of marine turtles and manatees, including wild or captive loggerhead sea turtles, Caretta caretta , from the western Mediterranean and Japan [9] [10] [11] [12], olive ridleys, Lepidochelys olivacea , and green turtles, Chelonia mydas , in the Pacific coast of Mexico [13] [14], and West Indian manatees, Trichechus manatus , in the western Caribbean [15] [16]. …”