Disseminated Toxoplasmosis in a Narrow-Ridged Finless Porpoise (Neophocaena asiaeorientalis) with Transplacental Embryonal Transmission.

We describe a case of systemic toxoplasmosis in a female adult narrow-ridged finless porpoise (Neophocaena asiaeorientalis) found in May 2018 inside a gillnet set in the Ariake Sound, southern Japan. The main lesions observed were lymphoplasmacytic and focally necrotizing encephalitis, necrotizing to granulomatous adrenalitis, myocarditis, and inflammation in the intestinal wall, associated with protozoal tissue cysts and tachyzoites. Additionally, the individual had a 5.6 mm (crown-rump length) early-stage embryo in the left uterine horn, which had multifocal necrotizing lesions with intralesional tissue cysts and tachyzoites in the parenchyma. Immunohistochemistry and PCR and sequencing of the internal transcribed spacer 1 region confirmed a Toxoplasma gondii infection. Further genotyping revealed an atypical type II genotype with a type I pattern for the Apico locus. Narrow-ridged finless porpoises are an endangered coastal species already facing various anthropogenic threats. Toxoplasmosis, especially with its ability to transmit to an early-stage embryo, should be considered an emerging threat to this vulnerable species.

Revision of the taxonomic status of Synthesium elongatum (Ozaki, 1935) (Brachycladiidae), an intestinal digenean of narrow-ridged finless porpoise (Neophocaena asiaeorientalis).

Synthesium elongatum (Brachycladiidae) is an intestinal digenean described from the finless porpoise (Neophocaena asiaeorientalis) in Japan. Few records of this species exist and there is a remarkable morphological similarity between S. elongatum and S. tursionis, such that a synonymy between the species has been suggested previously. However, no morphological and/or molecular analysis has been carried out to clarify the taxonomic status of S. elongatum. In this study, we collected specimens of Synthesium sp. from N. asiaeorientalis in western Japan. The specimens possess lobed testes within the third quarter of the body, a round ovary, and vitellaria extending to level of uterine field, which are diagnostic characters for both S. elongatum and S. tursionis. They were morphologically identified to S. elongatum or S. tursionis due to the fact that the available morphometric data for both species overlap remarkably. A molecular analysis of the mitochondrial ND3 gene showed that the pairwise nucleotide distances between these specimens and S. tursionis were small, and phylogenetic analysis showed that these specimens and S. tursionis are in the same clade. Therefore, it was indicated that S. elongatum and S. tursionis are the same species and, consequently, S. elongatum is a synonym of S. tursionis.

Potential association between exposure to legacy persistent organic pollutants and parasitic body burdens in Indo-Pacific finless porpoises from the Pearl River Estuary, China.

A high prevalence of infectious diseases (mostly lungworms) is found in finless porpoises (genus Neophocaena) in the coastal waters of China, which is one of the most dichlorodiphenyltrichloroethane (DDT)-polluted areas worldwide, while its association with contaminant exposure remains undetermined. To address this gap, we investigated blubber levels of polychlorinated diphenyls (PCBs), organochlorine pesticides (OCPs) and polycyclic aromatic hydrocarbons in Indo-Pacific finless porpoises (Neophocaena phocaenoides) stranded in the Pearl River Estuary (PRE) of China. In the post-mortem examinations, lungworms (Halocercus species) were found to be the most common parasites, with a high density observed in lungs and bronchi. Severe infections by nematode parasites were also found in the uterus (Cystidicola species), intestine (Anisakis typica) and muscle (A. typica). For all the pollutant compounds analyzed, only the concentrations of p,p'-DDT, p,p'-dichlorodiphenyldichloroethane (DDD) and o,p'-DDD were significantly higher in porpoises died of infectious diseases than in the "healthy" individuals (died from physical trauma). Contrasted accumulation pattern of DDTs and their metabolites was found between animals with different health status. The proportion of p,p'-DDT in ΣDDTs was higher than that of p,p'-dichlorodiphenyldichloroethylene (DDE) in diseased animals, whereas an opposite pattern was shown for "healthy" ones. While this study is the first to describe a significant positive correlation between parasitic diseases and high levels of DDTs in cetaceans, the direction of causality cannot be determined in our data: either a parasitic infection affected the porpoises' ability to metabolize DDTs, resulting in high levels of p,p'-DDT in their blubber, or the pollutant burden rendered them more susceptible to parasitic infection.

Metazoan parasites from odontocetes off New Zealand: new records.

Information about the parasite fauna of spectacled porpoises and cetaceans from New Zealand waters in general is scarce. This study takes advantage of material archived in collections of the Otago Museum in Dunedin and Massey University in Auckland, sampled from cetacean species found stranded along the New Zealand coastline between 2007 and 2014. Parasites from seven species of cetaceans (spectacled porpoise, Phocoena dioptrica (n = 2 individuals examined); pygmy sperm whale (n = 1); long-finned pilot whale, Globicephala melas (n = 1); Risso's dolphin, Grampus griseus (n = 1); short-beaked common dolphin, Delphinus delphis (n = 7); striped dolphin, Stenella coeruleoalba (n = 3) and dusky dolphin, Lagenorhynchus obscurus (n = 2)) from the respiratory and gastro-intestinal tract, cranial sinus, liver, urogenital and mammary tract, fascia and blubber were investigated. Ten parasite species were identified, belonging to the Nematoda (Stenurus minor, Stenurus globicephalae, Halocercus sp. (Pseudaliidae), Anisakis sp. (Anisakidae), Crassicauda sp. (Crassicaudidae)), Cestoda (Phyllobothrium delphini and Monorygma grimaldii (Phyllobothriidae)), Trematoda (Brachicladium palliata and Brachicladium delphini (Brachicladiidae)) and Crustacea (Scutocyamus antipodensis (Cyamidae)). Some of the parasite species encountered comprises new records for their host. Although the material was not sampled within a systematic parasitological survey, the findings contain valuable new information about the parasite fauna of rare, vagile and vulnerable marine wildlife from a remote oceanic environment.

Parasitic infections in the East Asian finless porpoise Neophocaena asiaeorientalis sunameri living off the Chinese Yellow/Bohai Sea coast.

Parasitic disease is among the major causes of health problems in marine mammals. However, little information on parasitic species composition and infection levels in finless porpoises (Neophocaena spp.) is available. In this study, we report the first systematic survey on parasitic infections in the East Asian finless porpoise N. asiaeorientalis sunameri (EAFP) living off the Chinese Yellow/Bohai Sea coast. Using both morphological and molecular methods, 5 parasitic helminths were identified: Campula oblonga in the liver and pancreas; Synthesium seymouri in the pyloric stomach and duodenum ampulla; Anisakis pegreffii in the forestomach, main stomach, and esophagus; Halocercus sp. in the lungs; and Crassicauda magna in the mammary glands and muscle. Among these helminths, C. oblonga (80.7%), S. seymouri (80.7%), A. pegreffii (80.7%), and Halocercus sp. (77.4%) were the most prevalent, whereas C. magna (6.5%) were only observed in 2 EAFP individuals. All juvenile and adult EAFPs were parasitized by at least 3 parasites species (C. oblonga, S. seymouri, and A. pegreffii), whereas in neonates, only Halocercus sp. were detected. We observed no significant difference in parasite prevalence between males and females. In addition, A. pegreffii and C. magna represented new infection records in Neophocaena. A pathological examination associated with parasitic lesions in EAFPs showed damage or destruction of cells or tissues to some extent. This study represents the first systematic survey on parasitic infections in EAFPs, providing important and valuable parasitological information for the research and conservation of this coastal marine mammal.

Population- and growth-related differences in helminthic fauna of finless porpoises (Neophocaena asiaeorientalis) in five Japanese populations.

A survey of helminths and ectoparasites, including epizoits, was conducted in narrow-ridged finless porpoises (Neophocaena asiaeorientalis) from Japanese five populations using dead stranded or incidentally caught animals. In total, 13 helminth species were found (6 nematodes, 4 trematodes, 2 cestodes and 1 acanthocephalan) in 137 porpoises. A new location record of Stenurus nanjingensis and a new host record of Tetrabothrius sp. were obtained. Eight species of helminth were considered common in the Japanese populations of the finless porpoise: Pharurus sunameri, Pharurus asiaeorientalis, Nasitrema spathulatum, Nasitrema sunameri, Halocercus pingi, Halocercus sunameri, Campula oblonga and Synthesium elongatum. No anisakid nematodes were found. N. spathulatum was found only in the western waters of the Seto Inland Sea. Low prevalence of C. oblonga in the Omura Bay was demonstrated. H. pingi was mostly found in very young porpoises before starting to eat prey, indicating prenatal or transmammary infection. However, a congeneric species, H. sunameri, mainly infected weaned porpoises, indicating that these two species possess different transmission pathways. This study provides information on the geographical distribution and prevalence of helminth parasites in finless porpoises off the Japanese coast.

Contamination status of POPs and BFRs and relationship with parasitic infection in finless porpoises (Neophocaena phocaenoides) from Seto Inland Sea and Omura Bay, Japan.

Contamination status of brominated flame retardants (BFRs) and persistent organic pollutants (POPs) in blubber of finless porpoises (Neophocaena phocaenoides) stranded along the coasts of Seto Inland Sea and Omura Bay in Japan were investigated. Levels of PCBs, DDTs and CHLs were significantly higher than those of HCHs, HCB, PBDEs and HBCDs. Concentrations of PBDEs and HBCDs, as well as organochlorine compounds in males increased with body length (p<0.05). Among 14 PBDE congeners analyzed, BDE-47 was the predominant, which is similar to those generally reported in biota. PBDEs, HBCDs and PCBs showed no obvious temporal trend in concentrations during the study period, suggesting continuous environmental release of these chemicals. On the other hand, levels of DDT, CHLs and HCHs have decreased. Concentrations of PCBs in liver trematode infected individuals were significantly higher than those in not infected individuals, implying there could be a relationship between contaminant levels and parasitic infection.

Temporal and spatial trends of organotin contamination in the livers of finless porpoises (Neophocaena phocaenoides) and their association with parasitic infection status.

Organotins (OTs) are globally ubiquitous contaminants. Contamination of OTs, particularly butyltins (BTs), has been suspected to cause immunosuppressive effects leading to subsequent infectious diseases or opportunistic infection by pathogens in marine mammals. In the present study, we collected individuals from five different populations of finless porpoises (Neophocaena phocaenoides) from coastal areas of Japan (Seto Inland Sea, Ise Bay, Omura Bay, and Pacific coast) and Hong Kong, and measured OT concentrations in their livers. In addition, infection status of lung nematodes and liver trematodes was also observed to analyze the relationship between OT contamination and parasitic infection in finless porpoises. Hepatic OT concentrations were highest in the Hong Kong population, while levels in the Japanese populations were equivalent to those of other cetaceans from different locations. OT levels in Japan have been decreasing in the past few decades, while OT contamination has shown little improvement in Hong Kong. Observation of parasite infection in Seto Inland Sea porpoises revealed that 16 and 11 out of 22 individuals were infected by lung nematodes and liver trematodes, respectively. Additionally, a significant association between BT levels and parasitic infection status of lung nematodes was detected. Thus, the present study suggests that BTs could be a factor affecting parasitic infection, especially the presence or severity of lung nematodes in finless porpoises. Since chemical exposure may alter the susceptibility of organisms to infectious diseases, the interaction of chemical contamination with infectious diseases needs to be investigated in greater depth to understand the risk of population decline due to these factors in marine mammals.

Parasites in stranded cetaceans of Patagonia.

There is an increasing interest in parasites of marine mammals of Argentina. Here, we examined several poorly known cetaceans, i.e., 2 spectacled porpoises and 1 Burmeister's porpoise (Phocoenidae), and 1 Gray's beaked whale and 1 Cuvier's beaked whale (Ziphidae); we also updated the parasite information for 1 sperm whale (Physeteridae). These hosts strand only occasionally. We found Anisakis simplex s.l. in 2 spectacled porpoises and the Burmeister's porpoise, and recorded its distribution among the stomach chambers. Anisakis physeteris infected the sperm whale; Corynosoma cetaceum occurred in the duodenal ampulla of the Burmeister's porpoise; Corynosoma australe was found in the posterior-most region of the intestine of 1 spectacled porpoise, while another one had Tetrabothrius sp. in the anal crypts; Corynosoma bullosum and Corynosoma sp. were found in the sperm whale. The only digenean found was Pholeter gastrophilus in the Burmeister's porpoise. Merocercoids of Phyllobothrium delphini were present in the blubber of 1 spectacled porpoise, the sperm whale, and the Gray's beaked whale, while Scolex pleuronectis infected the Gray's beaked whale and 1 spectacled porpoise. No parasites were recovered from the Cuvier's beaked whale. Poor parasite-species assemblages are consistent in marine mammals of Patagonia. Given the conservation status of these hosts, the limited parasitological information gathered is valuable for conservation or management of these hosts in Patagonia.

Isolation and characterization of Brucella from the lungworms of a harbor porpoise (Phocoena phocoena).

Adult female nematodes identified as Pseudalius inflexus were collected from the lungs of a juvenile male harbor porpoise (Phocoena phocoena) found dead on a beach in Cornwall, UK. Classic and molecular typing methods, immunologic and electron microscopy immunolabeling techniques, provided evidence of Brucella sp. infection within the uterine tissue of nematodes of this marine mammal. This finding presents further evidence to suggest parasites should be considered as a potential means of transfer of bacterial infection in marine mammals and highlights the zoonotic implications for humans exposed to marine mammals through occupation or leisure.

Macroparasites in stranded and bycaught harbour porpoises from German and Norwegian waters.

Parasitological investigations were carried out on harbour porpoises Phocoena phocoena originating from 3 different areas: the German North Sea (28), the German Baltic (18) and Norwegian waters (22). The individuals were bycaught in gill-nets or found stranded during the period 1997 to 2000. A total of 7 species of parasites was identified from the investigated organs. These originated mainly from the respiratory tract and comprised 1 ascaridoid nematode (Anisakis simplex), 4 pseudaliid nematodes (Pseudalius inflexus, Torynurus convolutus, Halocercus invaginatus, Stenurus minor) and 2 trematodes (Campula oblonga, Pholeter gastrophilus). This is the first geographic record of H. invaginatus from German waters. Differences were found in the severity of the parasitic infection between stranded and bycaught animals as well as between porpoises from different areas. A correlation was shown between parasitic infection and observed lesions.

Population structure of Anisakis simplex (Nematoda) in harbor porpoises Phocoena phocoena off Denmark.

The population structure and habitat selection of Anisakis simplex in 35 harbor porpoises off Denmark are described. The nematodes were collected from the stomach and duodenal ampulla and were categorized as third-stage larvae, fourth-stage larvae, subadults, and adults. The porpoises harbored 8,043 specimens of A. simplex. The proportion of adults and subadults increased with infrapopulation size. The number of development stages across infrapopulations covaried significantly (Kendall's test of concordance). Concordance was higher in hosts with the highest intensities than in those with low and medium intensities. All stages occurred mainly in the forestomach, but this trend was stronger for the adults. Adult and subadult sex ratios did not depart significantly from 1:1. Our data suggested that recruitment and duration of each stage were the main factors accounting for infrapopulation structure. The preference of A. simplex for the forestomach conformed with previous studies, but the narrower distribution of adults relative to other stages might indicate a strategy to enhance mating opportunities. Information on sex ratios of A. simplex is scarce and contradictory. We suggest that the discrepancies might partly reflect differences in categorization criteria and statistical methods.

Seroprevalence of Toxoplasma gondii antibodies in wild dolphins from the Spanish Mediterranean coast.

Although Toxoplasma gondii infection has been found occasionally in cetaceans, little is known of the prevalence of antibodies to T. gondii in wild dolphins. Antibodies to T. gondii were determined in serum samples from 58 dolphins stranded in the Spanish Mediterranean coast. Modified agglutination test was used to determine T. gondii antibodies, and a titer of 1:25 was considered indicative of T. gondii infection. Antibodies to T. gondii were found in 4 of 36 striped dolphins (Stenella coeruleoalba), in 2 of 4 common dolphins (Delphinus delphis), in 4 of 7 bottlenose dolphins (Tursiops truncatus), and in 1 harbour porpoise (Phocoena phocoena). Antibodies were not found in 9 Risso's dolphins (Grampus griseus) and in 1 long-finned pilot whale (Globicephala melas) surveyed. The results indicate that T. gondii infection is frequent in at least 3 dolphin species from the Mediterranean Sea.

Growth, fecundity and sex ratio of adult whaleworm (Anisakis simplex; Nematoda, Ascaridoidea, Anisakidae) in three whale species from the North-East Atlantic.

The growth rate, fecundity, and sex ratio of Anisakis simplex in minke whales (Balaenoptera acutorostrata), porpoises (Phocoena phocoena) and long-finned pilot whales (Globicephala melas) was studied on the basis of material from the North Atlantic. A total of 8,135 mature A. simplex were collected from 24 minke whales, 11 porpoises and eight pilot whales. For both males and females, the prevalence was 100% for all three host species, with a mean intensity of 1,727, 262 and 139, respectively. The mean body length of adult female A. simplex was 126 mm in minke whales, 71 mm in the porpoises and 73 mm in pilot whales; and for males the averages were, respectively, 106 mm, 57 mm and 68 mm. Eggs from the uteri of 32 females of length 87-176 mm collected in minke whale stomachs were counted in a Fuchs-Rosenthal chamber. Total egg production was measured in 14 females cultivated at sea. The female growth period was estimated to be 30-60 days, and apparently all eggs were shed during the last week of life. A female of size 150 mm produces approximately 1.5 million eggs. In the cultivation experiment, about 85% of the total egg production was shed during the first 3 days after spawning started.

Parasites from Indo-Pacific hump-backed dolphins (Sousa chinensis) and finless porpoises (Neophocaena phocaenoides) stranded in Hong Kong.

Between 1993 and 1998, 28 Indo-Pacific hump-backed dolphins (Sousa chinensis) and 32 finless porpoises (Neophocaena phocoenoides) stranded in Hong Kong territorial waters were examined postmortem for parasites. The nematode Halocercus pingi was discovered in the lungs of one hump-backed dolphin and in 10 finless porpoises, typically within abscesses or granulomata, and they were frequently accompanied by a catarrhal exudate and lesions characteristic of pneumonia. Seven of the 10 finless porpoises were calves with substantial lungworm infections, and three were neonates with visible fetal folds and umbilical remnants, suggesting that H pingi is transferred to the neonate before birth or during lactation. Electron micrographs of H pingi should allow the nematode to be identified by other researchers. An ectoparasitic stalked barnacle (Xenobalanus globicipitis) was recovered from a finless porpoise, the first time that this species of barnacle has been recorded in Hong Kong's territorial waters.

Evidence of infectious diseases in harbour porpoises (Phocoena phocoena) hunted in the waters of Greenland and by-caught in the German North Sea and Baltic Sea.

The pathological, microbiological and serological findings in harbour porpoises hunted in Greenlandic waters were compared with the findings in animals accidentally caught in fishing gear in the German North Sea and Baltic Sea. The body condition of the Greenlandic animals was good, whereas nine of 23 German harbour porpoises were moderately to markedly emaciated. Both groups were infested with parasites. In the Greenlandic animals parasitism of the aural peribullar cavity with Stenurus minor, of the liver and pancreas with Orthosplanchnus mironovi, of the lungs with Halocercus species and of the subcutaneous and mammary tissue with Crassicauda species was generally associated with a mild inflammatory response. No diseases associated with bacteria were identified in any of the Greenlandic harbour porpoises. In the porpoises from the German North Sea and Baltic Sea, parasites were present in the aural peribullar cavity (S minor), liver (Campula oblonga), first and second gastric compartment (Anisakis simplex) and in the lungs (Pseudalius inflexus and Torynurus convolutus). Moderate to marked pulmonary parasitism and suppurative pneumonia, not observed in the Greenlandic porpoises, were present in 11 and 10, respectively, of the 23 German porpoises. The suppurative pneumonia was attributed to bacterial infection with beta-haemolytic streptococci and Escherichia coil var haemolytica. Four Greenlandic and 10 German porpoises had positive porpoise morbillivirus-specific antibody titres suggesting that the virus was circulating in both populations.

Post-mortem findings in harbour porpoises (Phocoena phocoena) from the German North and Baltic Seas.

Between 1991 and 1996, necropsies were performed on 445 harbour porpoises (Phocoena phocoena), in various states of preservation, stranded on German coasts or accidentally caught by German fishermen. The animals originated from the North and Baltic Seas, and 133 were considered suitable for histopathological, immunohistochemical and microbiological examination. Most of the lesions in these 133 porpoises were caused by parasites, in particular in the respiratory tract, two-thirds of the animals exhibiting pneumonia associated with the parasites. Pneumonia was considered to be the cause of death in 46% of the stranded subadult and adult animals. The findings gave no evidence of any epidemic due to bacterial or viral infection. Bacteriological examination suggested that pneumonia was mainly caused by secondary bacterial infection and not by parasitic infestation alone. Beta-haemolytic streptococci were considered to be the main infectious agents. Morbillivirus antigen was not detected immunohistochemically.

Algunos helmintos de la marsopa espinosa, phocoena spinipinnis de la reserva nacional de Paracas, Perú / Some helminths of the porpoise, phocoena spinipinnis, of Paracas national reserve, Perú

Se informa de la presencia de 3 helmintos que parasitan a phocoene spinipinnis de la Reserva Nacional de Paracas, Ica, Perú: synthesium tursionis, pseudalius inflexus y stenurus australis. Por primera vez se encuentra en la costa S. tursionis parasitando a P. spinipinnis en la costa peruana

Bioaccumulation of selected trace elements in lung nematodes, Pseudalius inflexus, of harbor porpoise (Phocoena phocoena) in a Polish zone of the Baltic Sea.

Concentrations of Cd, Pb, Cu, Zn, Cr, Co, Ni, Mn and Fe were determined by AAS in lung nematodes and their host organ of harbor porpoise in the Polish zone of the Baltic Sea. Correlation coefficients computed for all element pairs indicate significant co-associations between concentrations of Zn and Mn as well as Mn and Fe in P. inflexus and the host organ, and for the pair Cu-Cr in the parasite. Based on both concentration and discrimination factors it is well documented that the metals studied, especially Fe, Mn and Zn are bioaccumulated in P. inflexus with respect to the host lung, showing significant inter-specimen variations.