Helminth communities of loggerhead turtles (Caretta caretta) from Central and Western Mediterranean Sea: the importance of host's ontogeny.
We investigated the factors providing structure to the helminth communities of 182 loggerhead sea turtles, Caretta caretta, collected in 6 localities from Central and Western Mediterranean. Fifteen helminth taxa (10 digeneans, 4 nematodes and 1 acanthocephalan) were identified, of which 12 were specialist to marine turtles; very low numbers of immature individuals of 3 species typical from fish or cetaceans were also found. These observations confirm the hypothesis that phylogenetic factors restrict community composition to helminth species specific to marine turtles. There were significant community dissimilarities between turtles from different localities, the overall pattern being compatible with the hypothesis that parasite communities reflect the ontogenetic shift that juvenile loggerheads undergo from oceanic to neritic habitats. The smallest turtles at the putative oceanic, pelagic-feeding stage harboured only the 2 digenean species that were regionally the most frequent, i.e. Enodiotrema megachondrus and Calycodes anthos; the largest turtles at the putative neritic, bottom-feeding stage harboured 11 helminth taxa, including 3 nematode species that were rare or absent in turtles that fed partially on pelagic prey. Mean species richness per host was low (range: 1.60-1.89) and did not differ between localities. Variance ratio tests indicated independent colonization of each helminth species. Both features are expected in ectothermic and vagrant hosts living in the marine environment.
Santoro
Mario
M
Department of Public Health Science, Section of Parasitology, Sapienza University of Rome, P.le Aldo Moro, Rome, Italy.
Badillo
Francisco J
FJ
Mattiucci
Simonetta
S
Nascetti
Giuseppe
G
Bentivegna
Flegra
F
Insacco
Gianni
G
Travaglini
Andrea
A
Paoletti
Michela
M
Kinsella
John M
JM
Tomás
Jesús
J
Raga
Juan A
JA
Aznar
Francisco J
FJ
D000818:Animals; D017163:Anisakis / Q000145:classification / Q000235:genetics / Q000254:growth & development; D051546:Cyclooxygenase 2 / Q000235:genetics; D004272:DNA, Mitochondrial / Q000235:genetics; D017753:Ecosystem; D006374:Helminthiasis, Animal / Q000469:parasitology; D006376:Helminths / Q000145:classification* / Q000302:isolation & purification / Q000502:physiology*; D006790:Host-Parasite Interactions; D007422:Intestines / Q000469:parasitology; D008522:Mediterranean Sea; D008969:Molecular Sequence Data; D017422:Sequence Analysis, DNA; D013045:Species Specificity; D013270:Stomach / Q000469:parasitology; D014426:Turtles / Q000254:growth & development* / Q000469:parasitology*
D004272:DNA, Mitochondrial; D051546:Cyclooxygenase 2