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1.
The associations between feeding activities and environmental variables inform animal feeding tactics that maximize energetic gains by minimizing energy costs while maximizing feeding success. Relevant studies in aquatic animals, particularly marine mammals, are scarce due to difficulties in the observation of feeding behaviors in aquatic environments. This data scarcity concurrently hinders ecosystem-based fishery management in the context of small toothed-cetacean conservation. In the present study, a passive acoustic monitoring station was deployed in an East Asian finless porpoise habitat in Laizhou Bay to investigate potential relationships between East Asian finless porpoises and their prey. The data revealed that porpoises were acoustically present nearly every day during the survey period. Porpoise detection rates differed between spring and autumn in concert with activities of fish choruses. During spring, fish choruses were present throughout the afternoon, and this was the time when porpoise vocalizations were the most frequently detected. During autumn, when fish choruses were absent, porpoise detection rates decreased, and diurnal patterns were not detected. The close association between fish choruses and finless porpoise activities implies an “eavesdropping” feeding strategy to maximize energetic gains, similar to other toothed cetaceans that are known to engage similar feeding strategies. Underwater noise pollution, particularly those masking fish choruses, could interrupt finless porpoises’ feeding success. Fisheries competing soniferous fishes with finless porpoise could impact finless porpoise viability through ecosystem disruption, in addition to fishing gear entanglement.  相似文献   

2.
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3.
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.  相似文献   

4.
Thymic cysts have not been previously reported in harbor porpoises (Phocoena phocoena). Two hundred forty stranded or "by-caught" harbor porpoises originating from the German North Sea and Baltic Sea and 14 animals from the waters of Greenland were necropsied. Thymuses of 78 porpoises of the North Sea and Baltic Sea were considered suitable for histopathologic examination based on the extent of postmortem autolysis. Immunohistochemistry using an anti-cytokeratin antibody was employed to demonstrate thymic epithelial structures in selected cases. Thymic macrocysts were rare and were only found in animals > or =7 years of age. Thymic microcysts, lined by a single cytokeratin-positive cell layer, were common in involuting thymuses, and the prevalence increased with advancing age. Thymic cysts might have arisen from degenerating Hassall's corpuscles or condensed epithelial reticulum. Thymuses were easily identified macroscopically in most adult healthy harbor porpoises, suggesting that physiological thymic involution proceeds slowly in this species.  相似文献   

5.
The pathological changes observed in the lungs of 197 freshly dead to moderately decomposed harbour porpoises (Phocoenaphocoena) stranded in England and Wales between October 1990 and December 1996 were reviewed. In 135 (69 per cent of the cases) macroscopic nematode infections of the bronchial tract with Pseudalius inflexus and Torynurus convolutus, either singly or in combination, were recorded, and 106 (54 per cent) also had P inflexus within the pulmonary blood vessels. All the macroscopically parasitised porpoises were adults or juveniles although two neonates had histological evidence of nematode infection. There were 62 cases of mild to severe, subacute to chronic bronchitis and bronchiolitis, 113 cases of mild to severe chronic granulomatous interstitial pneumonia, and 34 cases of mild to severe vasculitis or thrombovasculitis of pulmonary blood vessels attributable to these nematode infections. In 35 cases necropurulent or purulent (broncho)pneumonias were attributed either to secondary bacterial infections of the lungs or to septicaemias associated in seven cases with Streptococcus canis, in two cases with group B Salmonella species, in one case with Escherichia coli and in one case with Streptococcus lactis. The pulmonary lesions in 67 animals known or diagnosed to have been entrapped in fishing gear were non-specific and included persistent foam in the airways in 45 cases, diffuse congestion in 53, oedema in 50, and multifocal intra-alveolar haemorrhage in 33 cases. Seven cases of acute fibrinous or chronic fibrous pleuritis, seven cases of chronic necropurulent pneumonia associated with mycotic infections, four porpoises with traumatic lesions of the thorax and other parts of the body consistent with fatal attack from bottlenose dolphins (Tursiops truncatus), and one case of diffuse bronchointerstitial pneumonia associated with generalised morbillivirus infection were also recorded.  相似文献   

6.
The role of morbillivirus infection as a cause of disease or death in harbour porpoises (Phocoena phocoena) from the German North and Baltic Sea was investigated by serology, histology and immunohistochemistry. Blood and tissue samples of lung, brain and lymph nodes from 74 stranded or by-caught harbour porpoises from German waters were collected between 1991 and 1997. According to dentinal growth layers and body length, animals were grouped into four age classes (neonates, 0-1, 1-4, 4-16 years of age). Formalin-fixed, paraffin-embedded sections were stained by hematoxylin and eosin (HE). Immunohistology was done in all lung tissues using the avidin-biotin-peroxidase technique and a polyclonal canine distemper virus (CDV) nucleoprotein-specific antibody, which cross-reacts with porpoise morbillivirus (PMV) antigen. A virus neutralization assay for detection of (Onderstepoort-strain) CDV- and PMV-specific antibodies was performed. Due to the cytotoxicity of some sera, only titres of 1:20 or greater were considered positive. PMV or CDV-specific neutralizing antibody titres were found in 88 and 50% of the animals, respectively. Titres were always highest against PMV indicating infection with a homologous porpoise virus strain. There were no significant differences in neutralizing antibody titres between animals of the different age groups. No histological lesions specific for morbillivirus infection were detected and by immunohistology all cases were negative for morbillivirus antigen. The absence of morbillivirus antigen and the lack of characteristic morbillivirus-specific lesions showed that morbillivirus infection was not a cause of death or illness in the investigated population. However, the high incidence of PMV-specific antibodies in all age groups indicated a continuous spread of infection with a morbillivirus among harbour porpoises from the German Baltic and North Sea.  相似文献   

7.
Harbor porpoises from the North and Baltic Seas exhibit a higher incidence of bacterial infections compared to whales from less polluted arctic waters. Furthermore, thymic atrophy and splenic depletion, associated with elevated concentrations of environmental contaminants, such as polychlorinated biphenyls (PCB) and polybrominated diphenyl ether (PBDE) body burdens, have been found in wildlife harbor porpoises. Thus, there is currently a debate about the potential adverse effect of xenobiotics on the immune system and therefore on the health status of this and other marine mammal species. The aim of the present study was to characterize phenotypical changes in lymphoid organs of harbor porpoises and their possible association with increased disease susceptibility due to an impaired immune response in this marine mammal species. Therefore, 29 by-caught and stranded harbor porpoises were necropsied and the health status was evaluated based upon the severity of main pathological findings. In addition, the distribution of CD2-, CD3epsilon-, and CD45R-positive cells as well as B lymphocytes, MHC class II-expressing and antigen-presenting cells was determined in the thymus and spleen using immunohistochemistry. Thymic atrophy and splenic depletion were associated with an impaired health status in investigated whales. Phenotypical changes in atrophic thymuses were characterized by a depletion of immature cortical thymocytes and medullary B cells. Furthermore, findings in depleted spleens were consistent with a loss of peripheral T lymphocytes in the periarteriolar lymphoid sheath (PALS). Based upon the results, an altered thymopoiesis and impaired cellular immune function cannot be excluded in whales with evidence of lymphoid depletion.  相似文献   

8.
Semen sample was collected from two captive adult Yangtze finless porpoises ( Neophocaena phocaenoides asiaeorientalis ) during physical examination. One individual was aged about 9 years with body length 143 cm (total length) and body weight 46.1 kg in 2003. The age of the other was unknown and its body length was 147 cm and body weight was 43 kg in 2004. Ultrastructure of their spermatozoa was examined using scanning and transmission electron microscope. The sperm concentration was 4.17 × 109 spermatozoa per ml by the cytometer. The approximate dimensions of the spermatozoa were as follows: head length, 3.366 ± 0.140 μm (mean ± SE, n  = 15); head width, 1.896 ± 0.099 μm ( n  = 15); and neck length, 1.004 ± 0.074 μm ( n  = 10). The tail included midpiece, principal piece and terminal piece. The length of the midpiece was 1.882 ± 0.077 μm ( n  = 9). There is no apparent boundary between the principal piece and the terminal piece, so the length of the principal piece and the terminal piece was 44.612 ± 3.485 μm ( n  = 5). Total length of the spermatozoa was 53.314 ± 4.580 μm ( n  = 10). The acrosome covered approximately 45.8% of the anterior portion of the head.  相似文献   

9.
The purpose of this paper is to document recent additions to the South African barnacle (Cirripedia) fauna. New species records were obtained by examining accumulated collections of unidentified material in the Iziko South African Museum, as well as via material collected directly by the authors. Fourteen species, none of which are new to science, are added to the known fauna, raising the total number of barnacle species recorded from South Africa by over 20%, from 69 to 83 species. Ten of the additional species are offshore benthic forms and represent deep-water taxa whose ranges are extended into South African waters. The remaining four are coastal inshore or surface-dwelling species, of which three are considered recent anthropogenic introductions. The large number of additions to the fauna can be attributed to a long absence of taxonomic expertise on this group in the region and consequent accumulation of unidentified samples. A high proportion of the deep-water samples examined contained previously unreported species, suggesting that additional sampling of hard abyssal substrata in the region is certain to yield yet more new cirripede records.  相似文献   

10.
In the present study the occurrence of morbillivirus infection in harbour porpoises (Phocoena phocoena) from the Black Sea was investigated. Blood and tissue specimens of lung, brain and spleen from 73 stranded or by-caught harbour porpoises derived from the three Black Sea subregions such as Bulgaria, Georgia and Ukraine were collected between 1997 and 1999 and processed for histology, immunohistochemistry and serology. Age determination was performed according to dental growth layers and body length. The age of the investigated population ranged from neonates to a 12-year-old animal. Morbillivirus-specific neutralizing antibodies were detected in 53% of harbour porpoises. Generally, titres were very low and ranged from 20 to 270. There was no correlation between age, geographical origin and titre levels. The most common histological finding (97%) consisted of a mild to severe granulomatous bronchopneumonia due to lung worm infection. There were no changes indicative of a morbillivirus infection. Using immunohistology none of the animals were positive for morbillivirus antigen. However, the serological data are suggestive of a continuously circulating morbillivirus among harbour porpoises from the Black Sea indicating that harbour porpoises may serve as carriers for fatal diseases in susceptible cetacean species.  相似文献   

11.
Accurate diet identification of top predators is crucial to fully understand their ecological roles. Compared to terrestrial animals, gathering dietary information from cetaceans is notoriously difficult. Here, we applied a multilocus metabarcoding approach to investigate the diet of vulnerable Indo-Pacific humpback dolphins and Indo-Pacific finless porpoises from the Pearl River Estuary (PRE), China. Our analyses identified 21 prey fish species from the 42 humpback dolphin stomachs, as well as 10 species of fish and 1 species of cephalopod from the 13 finless porpoise stomachs. All of the taxa were assigned to the species level, highlighting that the multimarker approach could facilitate species identification. Most of the prey species were small- and medium-sized fishes that primarily fed on zooplankton. The calculated similarity index revealed a moderated dietary overlap between the 2 cetaceans, presumably due to the feeding of the 2 predators in association with fishing vessels in the PRE. A more diverse diet was observed in humpback dolphins in the closed fishing season compared to the fishing season, implying the influence on the dolphin diet due to the availability of commercial fishery resources. However, according to the results of species rarefaction curves, our findings on the feeding habits of the 2 cetaceans are still limited by insufficient sample size and therefore should be interpreted with caution. This study represents a first attempt to apply the multilocus DNA metabarcoding technique in the diet analysis of small cetaceans, although more efforts are needed to improve this type of analysis.  相似文献   

12.
Samples (blood or tissue fluid) from 594 arctic foxes (Alopex lagopus), 390 Svalbard reindeer (Rangifer tarandus platyrhynchus), 361 sibling voles (Microtus rossiaemeridionalis), 17 walruses (Odobenus rosmarus), 149 barnacle geese (Branta leucopsis), 58 kittiwakes (Rissa tridactyla), and 27 glaucous gulls (Larus hyperboreus) from Svalbard and nearby waters were assayed for antibodies against Toxoplasma gondii using a direct agglutination test. The proportion of seropositive animals was 43% in arctic foxes, 7% in barnacle geese, and 6% (1 of 17) in walruses. There were no seropositive Svalbard reindeer, sibling voles, glaucous gulls, or kittiwakes. The prevalence in the arctic fox was relatively high compared to previous reports from canid populations. There are no wild felids in Svalbard and domestic cats are prohibited, and the absence of antibodies against T. gondii among the herbivorous Svalbard reindeer and voles indicates that transmission of the parasite by oocysts is not likely to be an important mechanism in the Svalbard ecosystem. Our results suggest that migratory birds, such as the barnacle goose, may be the most important vectors bringing the parasite to Svalbard. In addition to transmission through infected prey and carrion, the age-seroprevalence profile in the fox population suggests that their infection levels are enhanced by vertical transmission.  相似文献   

13.
This case report describes orchitis in a stranded adult sexually mature free-living harbour porpoise (Phocoena phocoena). Orchitis, with or without epididymitis, is a rare finding in harbour porpoises and has been reported to be associated with infection with Brucella species or fungi. This porpoise was examined as part of an ongoing investigation into causes of death in harbour porpoises stranded on the Dutch coast. At necropsy, the animal was in very poor body condition and the most significant pathological change encountered was unilateral chronic granulomatous orchitis. Histologically, the seminiferous tubules were multifocally severely distended by large numbers of macrophages and fewer neutrophils that often showed central necrosis, with intra- and extracellular rod-shaped bacteria that stained negatively with Gram stain. No acid-fast bacteria, fungal elements, or spirochetes were detected when the lesions were stained with Ziehl-Neelsen, Fite-Faraco, Warthin-Starry, and Periodic acid-Schiff stains. Culture of samples taken from the testis revealed a pure culture of a bacterium of the Alcaligenaceae family. Further analysis by biochemistry, fatty acid profiling, and 16S rRNA gene sequencing techniques identified the bacterium as a Castellaniella species. The association of this bacterium with the observed lesions remains uncertain.  相似文献   

14.
The nematode fauna of 369 spotted mackerel of the species Scomber australasicus, collected off the northeastern Taiwanese coast of the northwestern Pacific, was investigated monthly from April 2004 to March 2005. The following nematode species were recorded: Anisakis simplex complex, Hysterothylacium aduncum, Porrocaecum decipiens and Raphidascaris trichiuri. The seasonal variation in the infection with A. simplex third stage larva (L3) was studied throughout the 12 months. The prevalence of A. simplex L3 recorded for total fish samples was 93.6%, varying between 86.7 and 100%. There was an increase in the abundance of this nematode in spring, with the peak occurring in April. To reveal whether intrinsic factors of the spotted mackerel host contributed to infection with this nematode, fish were grouped according to their body weight, age and gonad development (reported as gonadoosomatic index, GSI), respectively, and infection parameters (i.e., prevalence, abundance and intensity) were analyzed. Results showed that abundance was significantly higher in both larger (>450 g) and older (>3 years old) fish. The gonad development of the host fish was not correlated with the intensity of the larval infection in both female and male fish. Two distinct Anisakis species were identified by PCR-RFLP, namely A. pegreffii and a recombinant genotype of A. pegreffii and A. simplex sensu stricto. These species occurred with frequencies of 97% and 3%, respectively. The usefulness of using parasites as biomarkers for spotted mackerel stock identification around Taiwanese waters was confirmed herein. A second group of 58 spotted mackerel were obtained from the coastal waters off southwestern Taiwan. In addition to the two species, A. pegreffii and the recombinant one, which were found with frequencies of 63% and 9%, respectively, an additional Anisakis species A. typica was identified with a frequency of 28% from these fish. Two spotted mackerel stocks could thus be identified based on their infrastructure of Anisakis species community and their frequency. To the best of our knowledge, this is the first report of stock identification of spotted mackerel using endoparasite biomarkers.  相似文献   

15.
Infection with influenza A (H5N1) virus, which has not been associated with respiratory disease in humans previously, caused clinical signs of acute respiratory distress syndrome and multiple-organ dysfunction syndrome with high mortality in humans in Hong Kong in 1997. To study the pathogenesis of this disease, we infected four cynomolgus monkeys (Macaca fascicularis) with 2.5 x 104 median tissue culture infectious dose (TCID50) of influenza virus A/Hong Kong/156/97 (H5N1) and euthanatized them 4 or 7 days after infection. The main lesion was a necrotizing broncho-interstitial pneumonia (4/4) similar to those found in primary influenza virus pneumonia in humans, with desquamation of respiratory epithelium (4/4), intra-alveolar hemorrhage (4/4), hyaline membrane formation (2/4), and infiltration with neutrophils and macrophages (4/4). Lesions in other organs consisted of a suppurative tonsillitis (2/4) and necrosis in lymphoid organs (1/4), kidney (1/4), and liver (1/4). By immunohistochemistry, influenza virus antigen was limited to pulmonary tissue (4/4) and tonsils (2/4). Based on these results, we suggest that the cynomolgus monkey is a suitable animal model for studying the pathogenesis of human H5N1 virus infection and that multiple-organ dysfunction syndrome in this disease may be caused by diffuse alveolar damage from virus replication in the lungs alone.  相似文献   

16.
Dermatitis associated with microfilariae of a nematode of the superfamily Filarioidea was diagnosed in 10 dogs from the western United States. Clinically, lesions were single or multiple papules and plaques with alopecia, scarring, erythema, ulceration, or crusting. Eight dogs had lesional pruritus. Microscopically, there was perivascular, periglandular, to interstitial inflammation, with many eosinophils and/or plasma cells, and scarring affecting the dermis and subcutis. Microgranulomas containing microfilaria were seen in six dogs. Microfilariae were noted in microgranulomas or free in the dermis or subcutis, but not in vessels. In one case, an adult female nematode emerged from a biopsy sample that was placed in physiologic saline. Study of this nematode revealed that it was a filarioid of the family Onchocercidae; it was identified as Acanthocheilonema sp. (syn: Dipetalonema ). Antigen tests of five dogs were negative for Dirofilaria immitis . The Knott tests and/or filter tests of nine dogs were negative for microfilariae. An indirect fluorescence antibody test of one dog was also negative for D. immitis . One dog was not evaluated for microfilariae.  相似文献   

17.
Two common porpoises (Phocoena phocoena), one found stranded on the Isle of Sheppey, Kent, and the other in the Moray Firth, Scotland, in late 1990, were examined post mortem. Lesions of diffuse bronchointerstitial pneumonia were present in both animals; they were characterised by the infiltration of alveoli with leucocytes, macrophages and multinucleate syncytia, the necrosis of bronchial and bronchiolar epithelium, focal proliferation of type II pneumocytes and occasional acidophilic cytoplasmic inclusions in alveolar macrophages and syncytia. Lymphoid depletion was apparent in the spleen, thymus and lymph nodes of both porpoises. Other changes in the Isle of Sheppey porpoise included severe dacryoadenitis. Marked pharyngitis, oesophagitis and balanoposthitis were present in the Moray Firth porpoise. Immunoperoxidase staining revealed the presence of morbillivirus antigen in a range of epithelia from both porpoises. This is the first report of morbillivirus infection in cetaceans from the coast of Great Britain.  相似文献   

18.
H9N2亚型禽流感病毒自1994年在中国首次发现以来,一直在家禽中流行,其导致的产蛋下降和发病死亡给养禽业发展带来严重危害。以前的研究发现中国的H9N2亚型禽流感病毒在进化过程中形成多个基因型,其表面抗原蛋白血凝素基因(HA)可被划分为以A/chicken/Beijing/1/94、A/quail/Hong Kong/G1/97(G1)和A/chicken/Heilongjiang/35/01等为代表的3个亚群,神经氨酸酶基因(NA)可被划分为以A/chicken/Beijing/1/94、A/quail/Hong Kong/G1/97(G1)和A/chicken/Hong Kong/G9/97(G9)等为代表的3个亚群。其中类G1病毒的HA基因只在香港分离株中出现。本研究对我国2003年～2004年从禽类中分离的H9N2亚型禽流感病毒血凝素(HA)和神经氨酸酶(NA)基因进行测定和遗传演化分析,结果表明其中11株病毒的HA基因属于CK/BJ/1/94群系,NA基因属于CK/BJ/1/94或DK/HK/G9/97群系,并首次发现两株病毒含有类G1病毒HA和NA基因,而且这些类G1病毒具有不同的抗原性以及人流感病毒的受体结合位点。本研究结果提示应对H9N2病毒的防治及其公共卫生意义予以高度重视。  相似文献   

19.
Direct bird-to-human transmission, with the production of severe respiratory disease and human mortality, is unique to the Hong Kong-origin H5N1 highly pathogenic avian influenza (HPAI) virus, which was originally isolated from a disease outbreak in chickens. The pathobiology of the A/chicken/Hong Kong/220/97 (H5N1) (HK/220) HPAI virus was investigated in chickens, turkeys, Japanese and Bobwhite quail, guinea fowl, pheasants, and partridges, where it produced 75-100% mortality within 10 days. Depression, mucoid diarrhea, and neurologic dysfunction were common clinical manifestations of disease. Grossly, the most severe and consistent lesions included splenomegaly, pulmonary edema and congestion, and hemorrhages in enteric lymphoid areas, on serosal surfaces, and in skeletal muscle. Histologic lesions were observed in multiple organs and were characterized by exudation, hemorrhage, necrosis, inflammation, or a combination of these features. The lung, heart, brain, spleen, and adrenal glands were the most consistently affected, and viral antigen was most often detected by immunohistochemistry in the parenchyma of these organs. The pathogenesis of infection with the HK/220 HPAI virus in these species was twofold. Early mortality occurring at 1-2 days postinoculation (DPI) corresponded to severe pulmonary edema and congestion and virus localization within the vascular endothelium. Mortality occurring after 2 DPI was related to systemic biochemical imbalance, multiorgan failure, or a combination of these factors. The pathobiologic features were analogous to those experimentally induced with other HPAI viruses in domestic poultry.  相似文献   

20.
本研究用无特定病原体（ＳＰＦ）鸡胚增殖禽流感病毒鹅体分离株Ａ／Ｇｏｏｓｅ／Ｇｕａｎｇｄｏｎｇ／１／９６（Ｈ５Ｎ１）（ＧＤ１／９６）,提取病毒基因组总ＲＮＡ,运用反转录－聚合酶链反应（ＲＴ－ＰＣＲ）技术分别扩增该病毒分离株的８个基因片段的ｃＤＮＡ,分别克隆后进行序列测定。序列分析结果表明,所扩增到的８个片段均包含相应的病毒基因的完整开放阅读框架。ＧＤ１／９６株与１９９７年香港禽流感事件中的４株香港流感病毒分离株（分别来自人、鸡、鸭和鹅）的ＨＡ基因的高度同源性说明它们可能起源于同一种系,但ＮＳ基因的差异说明它们分属于不同的基因群系。ＧＤ１／９６株与香港流感病毒分离株的核苷酸和推导的氨基酸序列的同源性较低（６３．９％￣９８．１％）,而香港流感病毒分离株之间的核苷酸和氨基酸序列的同源性很高（９６．５％￣１００％）,且香  相似文献   

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