A Light Microscopic Comparison of The Cysts of Four Species of Sarcocystis Infecting The Domestic Reindeer (Rangifer Tarandus) in Northern Norway

Fresh preparations of micro-isolated sarcocysts from skeletal and cardiac muscle of 12 reindeer were examined by light microscopy. On the basis of cyst structure and cyst wall structure 4 Sarcocystis spp. could be differentiated. New names have been proposed for 2 previously unnamed Sarcocystis spp. of reindeer, and S. grueneri has been redefined. S. rangiferi n. sp. had macroscopic cysts in skeletal muscle measuring 2106×403 µm. The cyst wall protrusions were finger-like and measured 13.2×6.7 µm. The cysts were surrounded by a layer of fibrillar material. S. tarandi n. sp. had micro- to macroscopic cysts primarily in skeletal muscle, but a few cysts were found in the heart of one animal. In skeletal muscle the cysts measured 999×75µm; in the heart the cysts were shorter and wider. The cyst wall protrusions were fingerlike and measured 9.2×2.2 µm. S. grueneri had micro- to macroscopic cysts in cardiac muscle measuring 581×137 µm. The cyst wall was thin and relatively smooth with no visible protrusions. Sarcocystis sp. had micro- to macroscopic, slender cysts in skeletal muscle measuring 916×64 µm. The cyst wall had tightly packed, short, knob-like protrusions. The cysts of this species were previously classified as cysts of S. grueneri.     

Strandings provide insight into social group structure of Atlantic white-sided dolphins

Atlantic white-sided dolphins (Lagenorhynchus acutus) are highly social odontocetes with a poorly understood tendency to mass strand. With limited capacity to study social ecology in the open ocean, mass strandings provide an opportunity to improve our understanding of group structure. Our study of 32 mass stranding events that occurred on Cape Cod, Massachusetts, between 1999 and 2009 identifies aspects of social ecology that vary across the year. A greater number of mass stranding events occurred outside of the breeding season and there was evidence of age-structuring during the breeding season. We find generally low average intragroup pairwise relatedness assessed across eight microsatellite loci in a subset of 16 mass stranding events. Mass stranded groups do not show higher than expected relatedness when compared to a baseline estimate derived from single-stranded individuals. Overall, our integration of genetic estimates of relatedness with data on sex and maturity-class from stranded specimens suggests that Atlantic white-sided dolphins fall near the more fluid end of the continuum from short-term, highly fluid social associations to long-term, stable groups represented among the odontocetes. Despite their tendency to mass strand, stable, kin-based associations are not a defining feature of social group structure in this species.     

What can cetacean stranding records tell us? A study of UK and Irish cetacean diversity over the past 100 years

There are many factors that may explain why cetaceans (whales, dolphins, and porpoises) strand. Around the UK and Ireland, over 20,000 stranding records have been collected since 1913, resulting in one of the longest, continuous, systematic stranding data sets in the world. We use this data set to investigate temporal and spatial trends in cetacean strandings and use generalized additive models (GAMs) to investigate correlates of strandings. We find a dramatic increase in strandings since the 1980s, most likely due to increases in recording effort, and the formation of formal strandings networks. We found no correlation between the numbers of cetaceans stranding each year and several potential environmental and anthropogenic predictors: storms, geomagnetic activity, North Atlantic Oscillations, sea‐surface temperature, and fishing catch. We suggest that this is because the scale of change in the variables is too coarse to detect any potential correlations. It may also highlight the idiosyncratic nature of species’ responses to external pressures, and further the need to investigate other potential correlates of strandings, such as bycatch and military sonar. Long‐term cetacean stranding data provide vital information on past and present diversity for common, rare, and inconspicuous species. This study underlines the importance of continued support for stranding networks.     

Sarcocystis Infection in Wild Reindeer (Rangifer Tarandus) From Hardangervidda in Southern Norway: with a Description of The Cysts of Sarcocystis Hardangeri N. Sp.

Fresh preparations of micro-isolated sarcosysts from skeletal muscle of 5 wild reindeer were examined by light microscopy. Slender, spindelshaped cysts measuring 821 × 60 µm, and having short knob-like cyst wall protrusions were found in all animals. In 1 animal cysts different in structure from the cysts of the 4 previously known Sarcocystis spp. of reindeer were found, These cysts are considered to be cysts of a new Sarcocystis sp. of reindeer, for which the name Sarcocystis hardangeri has been proposed. S. hardangeri n. sp. had macroscopic, ovoid to cylindrical cysts measuring 1667 (900–2570) × 819 (450–1575) µm. The cysts were surrounded by a 8–10 µm thick layer of fibrillar material. After removal of this layer, relatively few and irregularly spaced, slanting protrusions became visible. The 20–30 µm long protrusions were tongue-like, and were lying close to the surface of the cyst. Cysts of S. grueneri, S. rangiferi and S. tarandi were not demonstrated in the 5 wild reindeer examined.     

Sarcocystis hemionilatrantis (Sp. N.) life cycle in mule deer and coyotes.

Fifteen coyotes (Canis latrans) shed sporulated sporocysts in their feces after eating freshly ground skeletal muscles from a mule deer (Odocoileus hemionus hemionus) infected with microscopic-sized cysts of Sarcocystis. Sporocysts were shed intermittently from 12 to 36 days after ingestion of the infected meat. Sporocyst size averaged 14.4 X 9.3 mum. Eleven mule deer fawns orally inoculated with these sporocysts became infected and 9 of 11 died between post-inoculation days (PID) 27 and 63. Clinical signs of anorexia, weight loss, pyrexia and weakness were evident prior to death. A calf (Bos taurus) and two lambs (Ovis aries) orally inoculated with these sporocysts did not become infected and remained healthy throughout the experiments. Similarly, uninoculated control animals consisting of three mule deer fawns, two lambs and one calf remained healthy during the experiment. Preliminary histologic examinations conducted on selected tissues from all animals revealed microscopic-sized schizogonous stages in macrophages, between muscle fibers and near blood vessels in the esophagus, heart, biceps femoris, semi-membranosus, diaphragm and tongue from seven of eight fawns which died between PID 27 and 39. Developing or mature muscle cysts were not found in fawn tissue until PID 60. Sarcocysts were found in the three infected fawns examined after this time. Muscle cysts or earlier schizont stages were not found in tissues from the inoculated or uninoculated calves and lambs. A single muscle cyst was found in one control fawn; the other two control fawns were negative for both muscle cysts and other schizogonous stages. These results established that the life cycle of this species of Sarcocystis can be completed with coyotes as the definitive host and mule deer as the intermediate host. Based on the demonstrated host specificity and earlier findings, the name Sarcocystis hemionilatrantis is proposed for this parasite of mule deer and coyotes.     

Hematological,biochemical, and morphological parameters as prognostic indicators for stranded common dolphins (Delphinus delphis) from Cape Cod,Massachusetts, U.S.A.

The current paucity of published blood values and other clinically relevant data for short‐beaked common dolphins, Delphinus delphis, hinders the ability of veterinarians and responders to make well‐informed diagnoses and disposition decisions regarding live strandings of this species. This study examined hematologic, clinical chemistry, and physical parameters from 26 stranded common dolphins on Cape Cod, Massachusetts, in light of their postrelease survival data to evaluate each parameter's efficacy as a prognostic indicator. Statistically and clinically significant differences were found between failed and survived dolphins, including lower hematocrit, hemoglobin, TCO₂, and bicarbonate and higher blood urea nitrogen, uric acid, and length‐to‐girth ratios in animals that failed. In general when compared to survivors, failed dolphins exhibited acidosis, dehydration, lower PCVs, and decreased body condition. Additionally, failed dolphins had the highest ALT, AST, CK, LDH, GGT, and lactate values. These blood values combined with necropsy findings indicate that there are likely a variety of factors affecting postrelease survival, including both preexisting illness and stranding‐induced conditions such as capture myopathy. Closer evaluation of these parameters for stranded common dolphins on point of care analyzers in the field may allow stranding personnel to make better disposition decisions in the future.     

Cetacean strandings in Costa Rica (1966-1999)

Cetacean strandings in Costa Rica are reported for a period of 33 years, with a total of 35 strandings, 13 species and 247 individuals involved. The vast majority of documented strandings occurred on the Pacific coast and correspond to single individuals (32 and 28 strandings respectively). The highest stranding number was in the period from 1990 to 1999 (n = 24). Physeter catodon (cachalot or sperm whale) is the species with the highest frequency of strandings (n = 8) and the family Delphinidae has the majority of species (n = 8) and strandings (n = 22). No other general tendencies were determined with the existing data.     

Demographics and spatio‐temporal signature of the biotoxin domoic acid in California sea lion (Zalophus californianus) stranding records

California sea lions (Zalophus californianus) in otherwise good nutritional condition have been consistently affected by the marine biotoxin domoic acid since the late 1990s. In this study we evaluated the temporal and spatial stranding patterns of suspected and confirmed cases of domoic acid intoxicated sea lions from 1998 to 2006, using records of strandings along the California coast obtained from members of the California Marine Mammal Stranding Network. The majority of domoic acid cases were adult females (47%–82% of the total annual domoic acid cases), a contrast to strandings that were not related to domoic acid, which were generally dominated by juveniles and pups. Exposure to this biotoxin led to a 6.67‐fold increase in adult female strandings in 2000, and a 5.44‐fold increase in adult female deaths in 2006, relative to strandings and deaths of adult female not affected by domoic acid. Domoic acid cases have occurred annually since 1998 (except for 1999) between April and August, with clusters centered primarily at Pismo Beach (San Luis Obispo County), as well as at other beaches in San Luis Obispo, Monterey, Santa Cruz, Santa Barbara, Orange, and San Diego counties. The larger ecological and population level implications of increased domoic acid strandings and deaths, particularly among adult female sea lions, warrant further attention and need to be investigated.     

Were Multiple Stressors a ‘Perfect Storm’ for Northern Gulf of Mexico Bottlenose Dolphins (Tursiops truncatus) in 2011?

An unusual number of near term and neonatal bottlenose dolphin (Tursiops truncatus) mortalities occurred in the northern Gulf of Mexico (nGOM) in 2011, during the first calving season after two well documented environmental perturbations; sustained cold weather in 2010 and the Deepwater Horizon oil spill (DWHOS). Preceding the stranding event, large volumes of cold freshwater entered the nGOM due to unusually large snowmelt on the adjacent watershed, providing a third potential stressor. We consider the possibility that this extreme cold and freshwater event contributed to the pattern of perinatal dolphin strandings along the nGOM coast. During the 4-month period starting January 2011, 186 bottlenose dolphins, including 46% perinatal calves (nearly double the percentage for the same time period from 2003-2010) washed ashore from Louisiana to western Florida. Comparison of the frequency distribution of strandings to flow rates and water temperature at a monitoring buoy outside Mobile Bay, Alabama (the 4(th) largest freshwater drainage in the U.S.) and along the nGOM coast showed that dolphin strandings peaked in Julian weeks 5, 8, and 12 (February and March), following water temperature minima by 2-3 weeks. If dolphin condition was already poor due to depleted food resources, bacterial infection, or other factors, it is plausible that the spring freshet contributed to the timing and location of the unique stranding event in early 2011. These data provide strong observational evidence to assess links between the timing of the DWHOS, other local environmental stressors, and mortality of a top local predator. Targeted analyses of tissues from stranded dolphins will be essential to define a cause of death, and our findings highlight the importance of considering environmental data along with biological samples to interpret stranding patterns during and after an unusual mortality event.     

Demographic Clusters Identified within the Northern Gulf of Mexico Common Bottlenose Dolphin (Tursiops truncates) Unusual Mortality Event: January 2010 - June 2013

A multi-year unusual mortality event (UME) involving primarily common bottlenose dolphins (Tursiops truncates) was declared in the northern Gulf of Mexico (GoM) with an initial start date of February 2010 and remains ongoing as of August 2014. To examine potential changing characteristics of the UME over time, we compared the number and demographics of dolphin strandings from January 2010 through June 2013 across the entire GoM as well as against baseline (1990-2009) GoM stranding patterns. Years 2010 and 2011 had the highest annual number of stranded dolphins since Louisiana’s record began, and 2011 was one of the years with the highest strandings for both Mississippi and Alabama. Statewide, annual numbers of stranded dolphins were not elevated for GoM coasts of Florida or Texas during the UME period. Demographic, spatial, and temporal clusters identified within this UME included increased strandings in northern coastal Louisiana and Mississippi (March-May 2010); Barataria Bay, Louisiana (August 2010-December 2011); Mississippi and Alabama (2011, including a high prevalence and number of stranded perinates); and multiple GoM states during early 2013. While the causes of the GoM UME have not been determined, the location and magnitude of dolphin strandings during and the year following the 2010 Deepwater Horizon oil spill, including the Barataria Bay cluster from August 2010 to December 2011, overlap in time and space with locations that received heavy and prolonged oiling. There are, however, multiple known causes of previous GoM dolphin UMEs, including brevetoxicosis and dolphin morbillivirus. Additionally, increased dolphin strandings occurred in northern Louisiana and Mississippi before the Deepwater Horizon oil spill. Identification of spatial, temporal, and demographic clusters within the UME suggest that this mortality event may involve different contributing factors varying by location, time, and bottlenose dolphin populations that will be better discerned by incorporating diagnostic information, including histopathology.     

Sarcocystis transmitted by blood transfusion.

Merozoites were found in blood smears from calves, lambs, and pigs exhibiting signs of acute sarcocystosis after oral infection with sporocysts of Sarcocystis bovicanis, Sarcocystis ovicanis, and Sarcocystis suihominis. In each of 3 experiments, whole blood containing merozoites was transfused from an infected host to 2 uninfected recipients of the same species; 2 additional animals of the same species served as uninfected nontransfused controls. The bovine, ovine, and porcine donors all died of acute sarcocystosis. Clinical signs of sarcocystosis were not seen in any transfusion recipients or controls. All recipients and controls were killed and histologic specimens of esophagus, diaphragm, heart, skeletal muscle, and tongue were examined microscopically. Large numbers of intramuscular cysts were present in transfusion recipients, whereas few or no cysts were present in controls, indicating that S. bovicanis, S. ovicanis, and S. suihominis had been transmitted between intermediate hosts of the same species by blood transfusion.     

Prevalence of Sarcocystis spp. cysts in Japanese and imported beef (Loin: Musculus longissimus)

A survey was carried out to investigate the occurrence of Sarcocystis infection in the loin (Musculus longissimus) of Japanese and imported beef. In all, the muscle tissue of 482 samples were examined by histological method. The prevalence of Sarcocystis unspecified species cysts was lower in Japanese beef (total 6.31%: 0% in Holstein castrated, 12.96% in Holstein milk cow, 3.33% in Japanese shorthorn and 11.58% in Japanese black cattle) than in beef imported from America (36.78%) or Australia (29.49%). The infection density of imported beef, especially in American, was higher than in Japanese beef. All detected cysts except one were identified as Sarcocystis cruzi. One thick walled cyst was found in Australian beef but it could not be distinguished as either Sarcocystis hirsuta or Sarcocystis hominis.     

Infectivity of sarcocystis spp. from bison, elk, moose, and cattle for cattle via sporocysts from coyotes

Bison bison (bison), Cervus canadensis (elk), Alces alces (moose), and Bos taurus (cattle) musculature containing Sarcocystis spp. cysts was fed to laboratory raised Canis latrans (coyotes), Sporocysts collected from the feces of coyotes fed musculature of each of the ruminant species were fed to four groups of three laboratory-raised domestic calves, respectively, to determine if Sarcocystis spp. was transmissible from wild to domestic ruminants and if so, to compare clinical signs of infection and morphologic features of cysts with those resulting from infection with Sarcocystis bovicanis. All calves fed sporocysts of Sarcocystis from coyotes that ate bison or cattle muscle had similar clinical signs and harbored morphologically similar parasites, suggesting that both bison and cattle are intermediate hosts for S. bovicanis and that this species is transmissible between the two ruminant species. All calves fed sporocysts from coyotes that ate elk muscle or moose muscle remained asymptomatic but one calf in each group had intramuscular cysts. The finding of relatively large numbers of intramuscular cysts in one calf fed sporocysts of elk origin and smaller numbers in one calf fed sporocysts of moose origin could represent either spurious natural infections or indicate low infectivity of Sarcocystis spp. from elk and moose to cattle.     

Mass stranding of striped dolphin, Stenella coeruleoalba, at Augusta, Western Australia: notes on clinical pathology and general observations.

Seventeen striped dolphins, Stenella coeruleoalba, were found stranded on a West Australian beach. Three animals died before a rescue attempt was made and a further three died during the rescue. The remaining dolphins were released 24 km offshore and were not seen again. One dolphin was noted to have a broken mandible. Evidence of physical trauma to the other dolphins was minimal; one adult female was observed with some peeling skin. Blood was collected for analysis. All dolphins were slightly dehydrated and had a leukogram typical of a stressed animal. Plasma biochemistry reflected primary muscle trauma. There were no clues to the cause of the stranding; observed pathology reflected damage that occurred as a direct consequence of stranding.     

A mass stranding of white-sided dolphins (Lagenorhynchus acutus) in Ireland: biological and pathological studies

We give details of the biological and pathological findings in a mass stranding of 19 white-sided dolphins on the west coast of Ireland. The pod consisted of adults and calves; no juveniles were present. The calf of a recently parturient female was not found. The presence of small foetuses suggested that mating took place in late August or early September. The largest and oldest male was severely diseased but the remainder of the pod were in good health although some minor lesions were found. The site where the animals came ashore was compatible with the geomagnetic theory of mass strandings.     

Reproductive seasonality of a recently designated bottlenose dolphin stock near Charleston,South Carolina,U.S.A

Reproductive seasonality of common bottlenose dolphins (Tursiops truncatus) can be affected by numerous ecological and behavioral factors. In 2009, stock boundaries were revised to recognize a Charleston Estuarine System Stock (CESS) of bottlenose dolphins in Charleston, South Carolina. The CESS is a well‐studied population with long‐term data collected from photo‐identification and stranding studies. From 2004 to 2008, a systematic mark‐recapture photo‐identification study was conducted in the Charleston Estuary to estimate population size of the CESS. Sightings data from this photo‐identification study coupled with strandings data (1993–2008) were analyzed to determine the reproductive seasonality of this local population. Both neonate sightings and strandings depicted a primary season of reproduction in the spring into early summer with a small peak in neonate sightings in early autumn, and were significantly different from circular uniform and Von Mises distributions (strandings: P < 0.01, V = 2.8644; sightings: P < 0.01, V = 3.2302). This study increases the knowledge of seasonal reproductive patterns of estuarine stocks of bottlenose dolphin stocks in the southeastern United States. The results will also help wildlife managers detect unusual neonate mortality events, and provide information about critical habitat relevant for evaluating and mitigating coastal development projects.     

Hearing loss in stranded odontocete dolphins and whales

The causes of dolphin and whale stranding can often be difficult to determine. Because toothed whales rely on echolocation for orientation and feeding, hearing deficits could lead to stranding. We report on the results of auditory evoked potential measurements from eight species of odontocete cetaceans that were found stranded or severely entangled in fishing gear during the period 2004 through 2009. Approximately 57% of the bottlenose dolphins and 36% of the rough-toothed dolphins had significant hearing deficits with a reduction in sensitivity equivalent to severe (70-90 dB) or profound (>90 dB) hearing loss in humans. The only stranded short-finned pilot whale examined had profound hearing loss. No impairments were detected in seven Risso's dolphins from three different stranding events, two pygmy killer whales, one Atlantic spotted dolphin, one spinner dolphin, or a juvenile Gervais' beaked whale. Hearing impairment could play a significant role in some cetacean stranding events, and the hearing of all cetaceans in rehabilitation should be tested.