Abstract

Lepidochelys olivacea is one of the sea turtle species found along the Brazilian coastline.³ Due to the risk of extinction, the species is considered vulnerable.¹ Spirorchiids (Digenea: Spirorchiidae) are a group of trematodes that parasitize the circulatory systems of turtles. Of the 19 known genera, 10 parasitize sea turtles exclusively and have been reported in Chelonia mydas, Caretta caretta, and Eretmochelys imbricata.^4,7 The life cycle of these parasites in marine environments has not been clarified, and the lesions they cause usually manifest as granulomas containing the parasites' eggs in essentially all animals.^2,5,8 There is only one report of lesions caused by spirorchiids in L. olivacea.⁶ The present study reports on the infection of L. olivacea with spirorchiids. The turtles analyzed were L. olivacea found stranded on the beaches of the states of Rio de Janeiro and Espírito Santo, Brazil, between 2011 and 2012. In total, five turtles (all females) were necropsied. Curved carapace length was between 67.1 cm and 73.3 cm. Two animals were found in 2011, and three were found in 2012. Gross visual inspection revealed poor body score in four turtles.⁷ On necropsy, no spirorchiids were detected, and the most evident changes were spleen congestion and evident lobular liver pattern. Organ samples were collected, fixed in 10% buffered formalin for at least 48 h and subsequently processed according to the routine histological techniques. Microscopy inspection revealed the infection with trematodes of the family Spirorchiidae, based on the detection of eggs that were classified according to a methodology previously described.⁹ Eggs were oval-shaped (type 3: genera: Neospirorchis), or fusiform, with lateral processes (type 1: genera Learedius, Monticellius, and Hapalotrema). Of the five turtles examined, only one presented fusiform eggs. Eggs were detected in the telencephalon, lung, spleen, and intestinal serosa. Giant cell granulomas were observed focally in intestine, lung, and spleen. It is known that lesions attributed to spirorchiidiosis may be severe in other species, but little information has been published describing the disease in L. olivacea. There is only one report of lesions caused by parasites of the Spirorchiidae family in L. olivacea. In that study, the eggs were type 1 and located in lungs, spleen, and intestines associated with granulomatous inflammatory reaction in one male turtle from Costa Rica.⁶ Similarly, in the present study no spirorchiids were detected in the host analyzed. Apparently, the inflammatory reaction recorded in L. olivacea is compatible with findings published in other studies.^2,4,5,9 However, we considered the infections detected as random,⁸ since it was not possible to determine whether death was actually caused by spirorchiids.

Acknowledgements

The authors wish to thank Dr. Bruno Berger, of the company CTA -Meio Ambiente, and Dr. Cecília Baptistotte, of Projeto TAMAR - ICMbio, for allowing to use the samples analyzed in the present study.

* Presenting author

Literature Cited

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