Dolphins Stranded along the Tuscan Coastline (Central Italy) of the “Pelagos Sanctuary”: A Parasitological Investigation

Parasite monitoring is considered a necessary step for cetacean management and conservation. Between February 2013 and July 2015, 26 dolphins (15 Stenella coeruleoalba, 10 Tursiops truncatus, and one Grampus griseus) stranded along the Tuscan coastline of the protected marine area “Pelagos Sanctuary”, were examined. Organs, tissues, and faecal and blood samples taken from all animals were analysed by parasitological, immunological, and molecular techniques. Twenty-one out of 26 dolphins (80.77%) tested positive for at least one parasite species, and 13/15 (86.7%) S. coeruleoalba, 7/10 (70%) T. truncatus, and the single G. griseus were found positive. Identified parasites included the nematodes Skrjabinalius guevarai (7.69%, 2/26), Halocercus lagenorhynchi (3.85%, 1/26), Halocercus delphini (7.69%, 2/26), Stenurus ovatus (7.69%, 2/26), Crassicauda spp. (7.69%, 2/26); the trematodes Pholeter gastrophilus (26.92%, 7/26), Campula palliata (3.85%, 1/26); the cestodes Phyllobothrium delphini (42.31%, 11/26), Monorygma grimaldii (23.08%, 6/26), Tetrabothrium forsteri (7.69%, 2/26), Strobilocephalus triangularis (7.69%, 2/26), and the acanthocephalan Bolbosoma vasculosum (7.69%, 2/26). Moreover, 6/26 (23%) animals scored positive to Toxoplasma gondii at serology, but PCR confirmed the infection (T. gondii Type II genotype) in a single animal. In examined dolphins, obtained results showed a high prevalence of endoparasites, which included species considered as a cause of severe debilitation or deat

Parassiti dei delfini spiaggiati lungo le coste della Toscana dal 2013 al 2015

Nel periodo compreso tra Febbraio 2013 e Luglio 2015, sono stati esaminati 26 delfini (10 Tursiops truncatus, 15 Stenella coeruleoalba, 1 Grampus griseus) spiaggiati lungo le coste della Toscana al fine di valutare la presenza di parassiti. A tal fine, campioni di feci e sangue e tutti gli organi e i tessuti degli animali inclusi nello studio sono stati esaminati con analisi parassitologiche, immunologiche e molecolari. I dati ottenuti sono stati analizzati statisticamente. Ventuno dei 26 animali esaminati (80%) è risultato positivo per la presenza di almeno una specie parassitaria. In particolare, la prevalenza dei soggetti positivi è stata dell’86% in S. coeruleoalba e del 70% in T. truncatus. L’unico esemplare di G. griseus esaminato è risultato positivo. I parassiti identificati sono rappresentati dalle seguenti specie: Skrjabinalius guevarai (7,69%, 2/26), Halocercus lagenorhynchi (3,85%, 1/26), Halocercus delphini (7,69%, 2/26), Stenurus ovatus (7,69%, 2/26), Pholeter gastrophilus (26,92%, 7/26), Campula palliata (3,85%, 1/26), Bolbosoma vasculosum (7,69%, 2/26), Phyllobothrium delphini (42,31%, 11/26 ), Monorygma grimaldii (23,08%, 6/26), Tetrabothrius forsteri (7,69%, 2/26), Strobilocephalus triangularis (7,69%, 2/26). Infine, il 23,08% (6/26) degli animali esaminati è risultato sierologicamente positivo per Toxoplasma gondii ma la PCR ha confermato la presenza del parassita in un solo animale

PARASITES OF DOLPHINS STRANDED ALONG THE COAST OF TUSCANY (ITALY)

In recent years, an increase in the number of stranded cetaceans has been observed. In order to give a contribution to the knowledge of the parasite fauna of stranded dolphins, in the period between February 2013 and July 2015, 10 Tursiops truncatus, 15 Stenella coeruleoalba, 1 Grampus griseus stranded along the coast of Tuscany (Pelagos Sanctuary) were screened for the search of parasites. All organs and faecal samples were examined with parasitological techniques. Immunological and molecular techniques were used for the search of Toxoplasma gondii on serum and brain tissue samples, respectively, and for Giardia and Cryptosporidium on faecal samples. The prevalence of parasites and the corresponding confidence intervals (95% CI) were calculated and data were statistically analysed (p <0.05). Twenty-one out of 26 examined animals (80%) tested positive for of at least one parasitic species. Specifically, 86% (13/15) S. coeruleoalba, 70% (7/10) T. truncatus and the single G. griseus were found positive. Skrjabinalius guevarai (7.7%, 2/26), Halocercus lagenorhynchi (3.8%, 1/26), Halocercus delphini (7.7%, 2/26), Stenurus ovatus (7.7%, 2/26), Pholeter gastrophilus (26.9%, 7/26), Campula palliata (3.8%, 1/26), Bolbosoma vasculosum (7.7%, 2/26), Phyllobothrium delphini (42.3, 11/26), Monorygma grimaldii (23.9%, 6/26), Tetrabothrius forsteri (7.7%, 2/26), Strobilocephalus triangularis (7.7%, 2/26) were the identified parasite species. Moreover, 6 out of 26 (23.1%) dolphins serologically examined for T. gondii were found positive, but PCR confirmed the presence of the parasite in the brain of a single animal. At statistical analysis, parasitological prevalence and seropositivity to T. gondii were not significantly different between T. truncatus and S. coeruleoalba. The high prevalence of endoparasitic infections in the subjects herein examined and the isolation of parasitic species considered as a cause of severe debilitation or death, highlight the importance of parasite monitoring in investigations aimed to evaluate the health status of dolphins in the Tyrrhenian Sea