DIGENETIC TREMATODE COMMUNITY IN NESTING GREEN SEA TURTLES (CHELONIA MYDAS) FROM TORTUGUERO NATIONAL PARK, COSTA RICA

Case report: Blindness associated with Learedius learedi trematode infection in a green sea turtle, Chelonia mydas, of the northern Red Sea

Spirorchiid blood flukes are widespread in sea turtles, causing disease and mortality in their populations, with high prevalence in several ocean basins. Besides being leading parasitic causes of sea turtle strandings in several parts of the world, these infectious agents can cause endocarditis, vasculitis, thrombosis, miliary egg granulomas, and aneurysms, which ultimately may compromise the survival of green sea turtles. More severe cases may also result in multifocal granulomatous meningitis or pneumonia, both of which can be fatal. Herein, we report the first case of severe trematode infection, Caused by Learedius learedi, in a green sea turtle in the northern Red Sea; this infection is associated with bilateral blindness. Necropsy revealed multiple granulomas with intralesional trematode eggs in the optic nerve, eyes, spleen, heart, and lungs. The parasite was identified as Learedius learedi through specific primers of the ribosomal genome and COI sequences obtained from GenBank. Altogether, these findings emphasize the importance of recognizing the systemic nature of this particular fluke infection to ultimately protect the lives of these marine animals and ensure the sustainability of these species in the wild.

Helminth Fauna of Juvenile Green Sea Turtles (Chelonia mydas) from Rio de Janeiro State, Brazil

The helminth fauna of juvenile green sea turtles (Chelonia mydas Linnaeus, 1758) is still poorly known. Herein, we study the gastrointestinal helminths of 28 juvenile green sea turtles found stranded on the north coast of Rio de Janeiro state, Brazil. All turtles were infected showing a rich helminth fauna. In total, 14802 trematodes belonging to 30 species and 5 families including Micros-caphidiidae, Plagiorchiidae, Pronocephalidae, Hapalotrematidae, and Telorchiidae were recovered. An unidentified nematode specimens was also found. The mean intensity was 536 (95% CI = 362 - 853) (range: 1 - 2831), and the species richness was 7.86 (95% CI = 6.46 - 9.21) (range: 1 - 17). The coast of Rio de Janeiro state represents new locality records for Angiodictyum posterovitellatum, Microscaphidium aberrans, M. warui, Octangium hyphalum, O. sagitta, Enodiotrema reductum and Pleurogonius laterouterus. This study confirms that the green sea turtle harbors the richest helminth fauna among sea turtle species and provides useful information on the gastrointestinal helminths of a poorly known stage in the life cycle of this endangered chelonian.

Vermetid gastropods as key intermediate hosts for a lineage of marine turtle blood flukes (Digenea: Spirorchiidae), with evidence of transmission at a turtle rookery

Blood flukes of the family Spirorchiidae Stunkard, 1921 are significant pathogens of marine turtles, both in the wild and in captivity. Despite causing considerable disease and mortality, little is known about the life cycles of marine species, with just four reports globally. No complete life cycle has been elucidated for any named species of marine spirorchiid, but the group is reported to use vermetid and fissurellid gastropods, and terebelliform polychaetes as intermediate hosts. Here we report molecular evidence that nine related spirorchiid species infect vermetid gastropods as first intermediate hosts from four localities along the coast of Queensland, Australia. ITS2 rDNA and cox1 mtDNA sequence data generated from vermetid infections provides the first definitive identifications for the intermediate hosts for the four species of Hapalotrema Looss, 1899 and Learedius learedi Price, 1934. Additionally, we provide a new locality report for larval stages of Amphiorchis sp., and evidence of three additional unidentified spirorchiid species in Australian waters. Based on the wealth of infections from vermetids during this study, we conclude that the previous preliminary report of a fissurellid limpet as the intermediate host for L. learedi was likely mistaken. The nine species found infecting vermetids during this study form a strongly supported clade exclusive of species of the other two marine spirorchiid genera for which sequence data are available; Carettacola Manter & Larson, 1950 which falls sister to the vermetid-infecting clade + a small clade of freshwater spirorchiids, and Neospirorchis Price, 1934 which is distantly related to the vermetid-infecting clade. We provide further evidence that spirorchiid transmission can occur in closed system aquaria and show that spirorchiid transmission occurs at both an important turtle rookery (Heron Island, southern Great Barrier Reef, Australia) and foraging ground (Moreton Bay, Australia). We discuss the implications of our findings for the epidemiology of the disease, control in captivity, and the evolution of vermetid exploitation by the Spirorchiidae.

The biodiversity of marine trematodes: then, now and in the future

Trematodes are the richest class of platyhelminths in the marine environment, infecting all classes of marine vertebrates as sexual adults and many phyla of marine invertebrates as part of their life cycles. Despite the cryptic nature of their existence (almost all marine trematodes are internal parasites), they have been the focus of study for almost 250 years, with the first species described in 1774. Here we review progress in the study of the "biodiversity" of these parasites, contrasting the progress made in the last 50 years (post-1971) to that in the almost 200 years before it (pre-1972). We consider an understanding of biodiversity to require knowledge of the species present in the system, an understanding of their evolutionary relationships (which informs higher classification), and, specifically for trematodes, an understanding of their complex life cycles. The fauna is now large, comprising well over 5,000 species. Although species description continues, we see evidence of a slow-down in all aspects of discovery. There has been only one completely new family identified since 1984 and the proposal of new genera is in decline as is the description of new species, especially for those of tetrapods. However, the extent to which this slow-down reflects an approach to the richness asymptote is made uncertain by changes in the field; reduced effort and difficulty of study may be important components of the effect. Regardless of how close we are to a complete description of the fauna, we infer that the outline is well-understood although the details are not. Adoption of molecular methodologies over the last 40 years have complemented morphometric analyses to facilitate objective recognition of species; however, despite these objective data, there is still inconsistency between authors on species delimitation. Molecular methodologies have also completely revolutionised inference of relationships at all levels, from within genera to between orders, and underpinned elucidation of novel life cycles. We expect the next 50 years to produce further dividends from technological innovations. The backdrop to the field will be global environmental concerns and the growing problem of funding for basic biodiversity studies.

Some Digenetic Trematodes Found in a Loggerhead Sea Turtle (Caretta Caretta) from Brazil

This paper reports three recovered species of digeneans from an adult loggerhead sea turtle - Caretta caretta (Testudines, Cheloniidae) in Brazil. These trematodes include Diaschistorchis pandus (Pronocephalidae), Cymatocarpus solearis (Brachycoeliidae) and Rhytidodes gelatinosus (Rhytidodidae) The first two represent new geographic records. A list of helminths reported from the Neotropical region, Gulf of Mexico and USA (Florida) is presented.

Detection and molecular characteristics of Pyelosomum cochlear (Digenea: Pronocephalidae) in the urinary bladder of the green sea turtle (Chelonia mydas) in the Northwest Pacific Ocean

The genus Pyelosomum consists of parasitic flukes occurring primarily in marine turtles; Pyelosomum cochlear Looss 1899 is the only species of this genus that parasitizes the urinary bladder. In this study, we detected flukes in the urinary bladders of 20 of 88 green sea turtles (Chelonia mydas) harvested in the Ogasawara Islands, in the Northwest Pacific Ocean. We identified the flukes as P. cochlear based on detailed morphological observations and comparisons of morphometric measurements of the species reported previously. Nucleotide sequences of nuclear ribosomal 18S and 28S regions and the mitochondrial cytochrome c oxidase subunit 1 (COI) region were determined for the flukes. The 18S and 28S phylogenetic trees revealed that the species of the superfamily Pronocephaloidea, including P. cochlear, constituted a single clade, but the species of the family Pronocephalidae did not constitute a single taxon. These findings suggest that Pronocephalidae is a paraphyletic group. The COI sequences of P. cochlear exhibited high genetic diversity, suggesting that they would be useful markers to understand the genetic structure of the parasite and its evolutionary relationship with the host turtle populations. This is the first study to provide the nucleotide sequences of Pyelosomum species; these data will be available for further molecular studies of this genus and its related taxa.

Detection and molecular characteristics of Rhytidodoides sp. (Digenea: Rhytidodidae) from the gall bladder of green sea turtles (Chelonia mydas) in the Ogasawara Islands, Japan

Trematodes of the genus Rhytidodoides are parasitic in marine turtles. Of the already known species, Rhytidodoides similis Price, 1939, occurs especially in the gall bladder. In this study, we surveyed 73 green sea turtles (Chelonia mydas) in the Ogasawara Islands, Japan, and detected Rhytidodoides sp. from the gall bladders of 18 turtles. A detailed morphological analysis revealed that the forebody of Rhytidodoides sp. differed slightly in shape from that of R. similis. There has been no information on DNA sequences of the family Rhytidodidae. A molecular phylogeny based on 28S rDNA sequences of Rhytidodoides sp. and related taxa suggested that the Rhytidodidae is sister to the other families of Echinostomatoidea. The intraspecific diversity of Rhytidodoides sp. was examined by using DNA sequences of mitochondrial cytochrome c oxidase subunit 1 gene (COI). The population genetic features of the COI haplotypes demonstrated that Rhytidodoides sp. is highly diverse in the Ogasawara Islands. The DNA sequences determined in this study will contribute to the species identification of congeners and the taxonomic reconsideration of the Echinostomatoidea.

Desmogonius baldassinae n. sp. (Digenea: Pronocephalidae) collected in a green sea turtle-Chelonia mydas-from Brazil

The genus Desmogonius (Digenea: Pronocephalidae) is known only from sea turtles and currently contains two species: D. desmogonius Stephens, 1911 and D. loossi Chattopadhyaya, 1972. The present study describes a third species, Desmogonius baldassinae n. sp. found in a juvenile green sea turtle (Chelonia mydas) from Brazil. The new species is larger than its congeners in all dimensions, with vitellinic fields ending posterior to the ovary. In addition, we present a key for species identification and an emended diagnosis of the genus Desmogonius.

Colocolic Intussusception Associated with Octangium sp. (Digenea: Microscaphidiidae) in a Green Sea Turtle Chelonia mydas

Reports of intussusception in sea turtles are generally linked to marine debris ingestion; therefore, only a few cases of the disease are associated with parasitic infestations. The objective of this study was to describe the necropsy findings of the first reported case of colocolic intussusception in a green sea turtle Chelonia mydas, associated with the helminth Octangium sp. A juvenile female green sea turtle, which was registered and rescued by the team from the Cetaceans Project of Costa Branca, State University of Rio Grande do Norte, was examined. The animal died 1 d after being treated and was immediately submitted for necropsy. Our findings indicated that parasitic infestation by Octangium sp. in the green sea turtle caused intussusception and consequently led to the animal's death. Early diagnosis and surgical correction are fundamental for a good prognosis and, consequently, for successful rehabilitation of marine species.

Two New Species of Telorchis (Digenea: Telorchiidae) from a Green Turtle, Chelonia Mydas (Cheloniidae), from the Upper Texas Coast with a Key to North American Species of Telorchis

Sea turtles are difficult to sample because of their protected status; however, museum collections and sea turtle stranding networks provide unique opportunities for parasitological research. Four gastrointestinal tracts from stranded, endangered green turtles, Chelonia mydas, were collected between 1993 and 1995 from the upper Texas coast and opportunistically sampled for parasite fauna. Two new species of Telorchis, a common freshwater amphibian and reptilian intestinal parasite genus, were found and described. Telorchis marinus n. sp. differs from Telorchis mydas n. sp. by its short body length, lack of pharyngeal glands, long esophagus relative to total body length, short and straight cirrus sac, short ventral sucker to ovary length relative to total body length, and an ovary located in the anterior one-third of body; it differs from its congeners in the number of ovary lengths between the ventral sucker and ovary, the number of ventral sucker lengths the cirrus sac extends beyond the posterior margin of the ventral sucker, and the vitelline field extent. Telorchis mydas differs from its congeners in the number of ovary lengths between the ventral sucker and ovary, the number of ventral sucker lengths the cirrus sac extends beyond the posterior margin of the ventral sucker, and the combination of having its ovary position near the midbody and a long, sinuous cirrus sac that is 35-44% of the total body length. Given the taxonomic complexities within Telorchis, a revised key to North American species is provided using morphological characteristics to assist future researchers in delineating true species and appropriate synonymies with molecular explorations. We reject the majority of synonymies in the genus until molecular data are available; we accept the synonymies of Telorchis necturi as Telorchis stunkardi and Telorchis gutturosi as Telorchis chelopi. Both Telorchis linstowi and Telorchis stossichi should be considered as species inquirenda. This is the first confirmed report of Telorchis from a marine host and the first report on parasites of cheloniid sea turtles in Texas, and this study adds to the ever-growing evidence that collections are essential to understanding biodiversity.

Disease risk analysis in sea turtles: A baseline study to inform conservation efforts

The impact of a range of different threats has resulted in the listing of six out of seven sea turtle species on the IUCN Red List of endangered species. Disease risk analysis (DRA) tools are designed to provide objective, repeatable and documented assessment of the disease risks for a population and measures to reduce these risks through management options. To the best of our knowledge, DRAs have not previously been published for sea turtles, although disease is reported to contribute to sea turtle population decline. Here, a comprehensive list of health hazards is provided for all seven species of sea turtles. The possible risk these hazards pose to the health of sea turtles were assessed and "One Health" aspects of interacting with sea turtles were also investigated. The risk assessment was undertaken in collaboration with more than 30 experts in the field including veterinarians, microbiologists, social scientists, epidemiologists and stakeholders, in the form of two international workshops and one local workshop. The general finding of the DRA was the distinct lack of knowledge regarding a link between the presence of pathogens and diseases manifestation in sea turtles. A higher rate of disease in immunocompromised individuals was repeatedly reported and a possible link between immunosuppression and environmental contaminants as a result of anthropogenic influences was suggested. Society based conservation initiatives and as a result the cultural and social aspect of interacting with sea turtles appeared to need more attention and research. A risk management workshop was carried out to acquire the insights of local policy makers about management options for the risks relevant to Queensland and the options were evaluated considering their feasibility and effectiveness. The sea turtle DRA presented here, is a structured guide for future risk assessments to be used in specific scenarios such as translocation and head-starting programs.

Pronocephaloid cercariae (Platyhelminthes: Trematoda) from gastropods of the Queensland coast, Australia

The superfamily Pronocephaloidea Looss, 1899 comprises digeneans occurring in the gut and respiratory organs of fishes, turtles, marine iguanas, birds and mammals. Although many life cycles are known for species of the Notocotylidae Lühe, 1909 maturing in birds and mammals, relatively few are known for the remaining pronocephaloid lineages. We report the cercariae of five pronocephaloid species from marine gastropods of the Queensland coast, Australia. From Lizard Island, northern Great Barrier Reef, we report three cercariae, two from Rhinoclavis vertagus (Cerithiidae) and one from Nassarius coronatus (Nassariidae). From Moreton Bay, southern Queensland, an additional two cercariae are reported from two genotypes of the gastropod worm shell Thylacodes sp. (Vermetidae). Phylogenetic analysis using 28S rRNA gene sequences shows all five species are nested within the Pronocephaloidea, but not matching or particularly close to any previously sequenced taxon. In combination, phylogenetic and ecological evidence suggests that most of these species will prove to be pronocephalids parasitic in marine turtles. The Vermetidae is a new host family for the Pronocephaloidea.

First Report of Pyelosomum Cochlear Looss 1899 (Digenea: Pronocephalidae) in a Hawksbill Turtle - Eretmochelys Imbricata L. Found in Brazilian Coast

Pyelosomum cochlearLooss 1899 (Digenea: Pronocephalidae) is a parasite exclusive to sea turtles, having been described in the green turtle (Chelonia mydas) in Egypt, the USA, Panama, Costa Rica and Brazil as well as the olive ridley turtle (Lepidochelys olivacea) in Brazil. The present note describes the first occurrence of P. cochlear in a hawksbill turtle (Eretmochelys imbricata) found on the coast of Brazil.

Gastrointestinal investigation of parasites and Enterobacteriaceae in loggerhead sea turtles from Italian coasts

Background

Caretta caretta is the most abundant sea turtle species in the Mediterranean, and studies on this species have vastly expanded during recent years, including those investigating gut bacterial and parasitic communities. Members of these communities have been reported with variable prevalence and pathogenicity, mainly depending on their host and environment (e.g. lifespan, distribution, habitat, diet, health status and stressors). Indeed, many species commonly inhabiting the sea turtle gastrointestinal tract exhibit an opportunistic behaviour.

This study aimed to provide baseline data on enterobacterial and parasitic composition, through bacteriological culture-based methods and the FLOTAC parasitological technique, in cloacal and faecal samples of 30 live Caretta caretta, examined upon their arrival at the Marine Turtle Research Centre (Portici, Italy).

Results

Enterobacteriaceae were isolated in 18/23 cloacal samples (78.3%), with Citrobacter and Morganella as the most common genera, followed by Proteus, Enterobacter, Providencia, and Hafnia. Parasitic elements were detected in 11/30 faecal samples (36.7%), with Enodiotrema, Rhytidodes, and Eimeria as most common genera, followed by Pachypsolus and Cymatocarpus. Additionally, Angiodyctium is reported for the first time in this host. The majority (47.8%) of sea turtles hosted exclusively Enterobacteriaceae, whereas 30.4% hosted both parasites and Enterobacteriaceae; the remaining 21.8% hosted neither of the agents.

Conclusions

Bacteria and parasites evaluated in the present study are common in Mediterranean loggerhead sea turtles, with slight differences between the western and eastern basin. Although naturally present in the gastrointestinal system of free-living sea turtles, their relationship with these hosts might range from mutualism to parasitism. Indeed, members of the gut community might express their pathogenic potential in immune-compromised animals, such as those in rehabilitation facilities. Therefore, it is advisable to include in the standard work-up of rescued sea turtles a screening procedure for such opportunistic agents, in order to better evaluate the animal’s health status and achieve timely intervention with appropriate treatment, thus improving rehabilitation. Furthermore, data collected from free-living sea turtles represent a starting point for investigating wild populations. However, further studies are needed to clarify the differences between sea turtle’s normal gut microbiome and pathobiome.

Fatal Rameshwarotrema uterocrescens infection with ulcerative esophagitis and intravascular dissemination in green turtles

The trematode Rameshwarotrema uterocrescens (Digenea: Pronocephalidae) parasitizes the glands of the caudal esophagus of Chelonia mydas. In the present study, 741 C. mydas were examined, 85 animals had adult specimens of R. uterocrescens associated with necrotizing ulcerous esophagitis, of these 85, 21 presented invasion of the esophageal mural vessels in the caudal esophagus of juvenile green turtles (Chelonia mydas). Necrotizing granulomatous splenitis, hepatitis, and nephritis were associated with the presence of parasites. The eggs from R. uterocrescens are birefringent under plane-polarized light, which distinguishes them from those of spirorchiid trematodes. This study contributes novel data on R. uterocrescens, methods for detecting this parasite, and demonstrates the fatal potential of parasitism in C. mydas.

•

For the first time R. uterocrescens was associated with extra-esophageal lesions and esophageal obstruction.

•

R. uterocrescens infection in juvenile green turtles is fatal.

•

R. uterocrescens can disseminate to other organs through blood vessels.

The Genus Rhytidodoides Price, 1939 (Digenea: Rhytidodidae) in Brazil: New Geographic Occurrence and Report of Pathology in the Gallbladder

The present note describes the occurrence of Rhytidodoides intestinalis and Rhytidodoides similis (Digenea: Rhytidodidae) in the gallbladder of two juvenile green turtles (Chelonia mydas - Testudines, Cheloniidae) found on the coast of Brazil. Both were detected in gallbladder and intestine of green turtles: Rhytidodoides similis (United States, Panama, Costa Rica and Brazil) and R. intestinais (United States, Panama and Costa Rica). This note is the first report of R. intestinalis in Brazil and South-West Atlantic Ocean. Also the histological lesions caused by the parasites in one gallbladder are described.

Spirorchiidiasis in marine turtles: the current state of knowledge

Blood flukes of the family Spirorchiidae are important disease agents in marine turtles. The family is near cosmopolitan in distribution. Twenty-nine marine species across 10 genera are currently recognized, but taxonomic problems remain and it is likely that more species will be discovered. Spirorchiids infect the circulatory system, where they and their eggs cause a range of inflammatory lesions. Infection is sometimes implicated in the death of the turtle. In some regions, prevalence in stranded turtles is close to 100%. Knowledge of life cycles, important for control and epidemiological studies, has proven elusive until recently, when the first intermediate host identifications were made. Recent molecular studies of eggs and adult worms indicate that a considerable level of intrageneric and intraspecific diversity exists. The characterization of this diversity is likely to be of importance in exploring parasite taxonomy and ecology, unravelling life cycles, identifying the differential pathogenicity of genotypes and species, and developing antemortem diagnostic tools, all of which are major priorities for future spirorchiid research. Diagnosis to date has been reliant on copromicroscopy or necropsy, which both have significant limitations. The current lack of reliable antemortem diagnostic options is a roadblock to determining the true prevalence and epidemiology of spirorchiidiasis and the development of effective treatment regimes.

Is Amphiorchis (Digenea: Spirorchiidae) an Exclusive Parasite of Sea Turtles?

The side-necked turtle Hydromedusa tectifera commonly inhabits the tributary streams of the Rio de La Plata and occasionally is found in brackish waters within the estuary of the Rio de La Plata. Few studies have been conducted on its parasitic fauna, especially in Argentina. In the present work Amphiorchis sp. is registered for the first time in a freshwater turtle, expanding the knowledge about the specifi city of the genus that until now was considered inhabiting only marine turtles.

First evidence of polychaete intermediate hosts for Neospirorchis spp. marine turtle blood flukes (Trematoda: Spirorchiidae)

Life cycles of spirorchiids that infect the vascular system of turtles are poorly understood. Few life cycles of these blood flukes have been elucidated and all intermediate hosts reported are gastropods (Mollusca), regardless of whether the definitive host is a freshwater or a marine turtle. During a recent survey of blood fluke larvae in polychaetes on the coast of South Carolina, USA, spirorchiid-like cercariae were found to infect the polychaetes Amphitrite ornata (Terebellidae) and Enoplobranchus sanguineus (Polycirridae). Cercariae were large, furcate, with a ventral acetabulum, but no eyespots were observed. Partial sequences of D1-D2 domains of the large ribosomal subunit, the internal transcribed spacer 2, and the mitochondrial cytochrome oxidase 1 genes allowed the identification of sporocysts and cercariae as belonging to two unidentified Neospirorchis species reported from the green turtle, Chelonia mydas, in Florida: Neospirorchis sp. (Neogen 13) in A. ornata and Neospirorchis sp. (Neogen 14) in E. sanguineus. Phylogenetic analysis suggests that infection of annelids by blood flukes evolved separately in aporocotylids and spirorchiids. Our results support the contention that the Spirorchiidae is not a valid family and suggest that Neospirorchis is a monophyletic clade within the paraphyletic Spirorchiidae. Since specificity of spirorchiids for their intermediate hosts is broader than it was thus far assumed, surveys of annelids in turtle habitats are necessary to further our understanding of the life history of these pathogenic parasites.

Amphiorchis stacyi n. sp. (Digenea: Spirorchiidae) in the heart of a green turtle from Florida, USA and the literature review of Amphiorchis (Price, 1934)

The present paper reports the occurrence of the seventh species in the genus Amphiorchis (Digenea: Spirorchiidae) collected from the heart of a green turtle found in Florida, USA. A taxonomic key to the species of Amphiorchis and a literature review for the genus are presented.

Ecologia da comunidade de helmintos gastrointestinais de tartarugas-verdes ( Chelonia mydas ) recolhidas no litoral do Espírito Santo

RESUMO A tartaruga-verde, Chelonia mydas, apresenta distribuição cosmopolita. No Brasil, ocorre na costa, porém desova em ilhas oceânicas. A helmintofauna de tartarugas-verdes é diversificada, podendo-se dizer que tem a maior diversidade comparada com outras espécies de tartarugas. Objetivou-se avaliar aspectos ecológicos da comunidade de helmintos gastrointestinais e relacionar com a condição corporal de tartarugas-verdes recolhidas no litoral do Espírito Santo. Foram utilizados 36 exemplares juvenis da espécie C. mydas. O trato gastrointestinal foi separado e dividido em porções: esôfago/estômago, intestino delgado e intestino grosso. Cada porção foi inspecionada à procura de parasitos, e os exemplares encontrados foram separados para posterior identificação. Das 36 tartarugas avaliadas, 34 estavam parasitadas por helmintos (94,44%), com um total de 10.734 helmintos. Foram encontradas 18 espécies de trematodas pertencentes a quatro famílias. A riqueza de espécies encontrada foi de 4,29±2,19 (1-10) e a intensidade média de infecção foi de 315,64±281,83 (2-994) helmintos. Os parasitos mais prevalentes foram Cricocephalus albus, Metacetabulum invaginatum e Neoctangium travassosi, ambos com 61,11% (22/36), Pronocephalus obliquus com 33,33% (12/36), e Glyphicephalus lobatus com 30,55% (11/36). O helminto mais abundante foi M. invaginatum com 70,63 helmintos/animal, seguido de C. albus com 58,77 helmintos/animal e N. travassosi com 41,75 helmintos/animal.

Pathology and molecular analysis of Hapalotrema mistroides (Digenea: Spirorchiidae) infecting a Mediterranean loggerhead turtle Caretta caretta

Turtle blood flukes belonging to the family Spirorchiidae (Digenea) represent a major threat for sea turtle health and are considered the most important parasitic cause of turtle stranding and mortality worldwide. Despite the large diversity of spirorchiid species found globally, there are only 2 records for free-ranging Mediterranean sea turtles that date back to the late 1800s involving just Hapalotrema mistroides Monticelli, 1896. This study describes the first fatal confirmed case of spirorchiidiasis in a free-ranging Mediterranean loggerhead turtle Caretta caretta (Linnaeus) and, owing to the complexities of taxonomic identification of these parasites, provides the first molecular characterization and phylogenetic analysis of H. mistroides from the Mediterranean Sea. The loggerhead turtle showed cachexia and digestive disorders associated with severe damage to the pancreas and intestinal ganglia, caused by deposition of Hapalotrema eggs forming granulomas. Massive Hapalotrema egg emboli in several tissues and organs and encephalitis were the most probable contributions to the death of the turtle. The congruence between the phylogenetic analysis of both the ITS2 and 28S rDNA resolved the Italian and USA H. mistroides as the same species, confirming the parasite identification. The case here described clearly indicates that the blood flukes should be considered in the differential diagnosis of Mediterranean sea turtle diseases.

Checklist of sea turtles endohelminth in Neotropical region

This paper presents a list of parasites described in sea turtles from the Neotropical region. Through the review of literature the occurrence of 79 taxa of helminthes parasites were observed, mostly consisting of the Phylum Platyhelminthes with 76 species distributed in 14 families and 2 families of the Phylum Nematoda within 3 species. Regarding the parasite records, the most studied host was the green turtle (Chelonia mydas) followed by the hawksbill turtle (Eretmochelys imbricata), olive ridley turtle (Lepidochelys olivacea), loggerhead turtle (Caretta caretta) and leatherback turtle (Dermochelys coriacea). Overall helminths were reported in 12 countries and in the Caribbean Sea region. This checklist is the largest compilation of data on helminths found in sea turtles in the Neotropical region.

Report of the fourth specimen of Amphiorchis solus (Simha & Chattopadhyaya, 1970) Platt, 2002 46 years after the original description

The aim of this paper was to describe the occurrence of the fourth specimen of Amphiorchis solus (Simha & Chattopadhyaya, 1970) Platt, 2002 (Digenea: Spirorchiidae) in a green turtle (Chelonia mydas L.1758) found in northeastern Brazil. Amphiorchis solus is a parasite that has only been reported in green turtles in India, Costa Rica and Brazil. Although the original description was made in 1970, only four specimens (including the one described herein) have been reported in the literature. In this note, we present the second occurrence of A. solus in Brazil, broadening information on the species and providing the first photographic record of this parasite.

Helminth fauna of Chelonia mydas (Linnaeus, 1758) in the south of Espírito Santo State in Brasil

Due to an inadequate knowledge about threats to the sea turtle, we aimed to evaluate the helminth fauna of Chelonia mydas which had died on the southern coast of Espirito Santo, Brasil and described the associated tissue pathological lesions. Retrospective and prospective studies on turtle parasites were conducted and tissues samples were collected. 106 of 212 of sea turtles (50 %) were parasitized, and 47 of 106 of infected animals 43.0 % (47/106) were in poor health condition. Seven trematoda families covering 19 different helminths species were identified. Turtles were inhabited with one or more species of parasites, and there was no significant association between parasitism and weakness of the animals. Trematode eggs, with or without giant cells in tissues of various organs were observed.

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.

Postmortem diagnostic investigation of disease in free-ranging marine turtle populations: a review of common pathologic findings and protocols

Over the past few decades, there have been increasing numbers of reports of diseases in marine turtles. Furthermore, in recent years, there have been documented instances of apparently new diseases emerging in these species of which the etiology and/or pathogenesis remain unknown. These instances i) raise concern for the survival of marine turtles, and ii) question the health and stability of the benthic marine environments in which turtles live. Knowledge of common disease processes and pathologic changes in lesions, along with a standardized approach to postmortem and sample collection are required to document and understand the host-agent-environment interactions in marine turtle health. This review combines, for the first time, a standardized approach to the postmortem of marine turtles for veterinary clinicians, with a concurrent descriptive review of the gross and microscopic pathologic changes in lesions commonly seen.