Apparent Seroprevalence of Salmonella spp. in Harp Seals in the Greenland Sea as Determined by Enzyme-linked Immunosorbent Assay

An indirect ELISA was developed as a possible tool for surveillance of the seroprevalence of Salmonella spp. in harp seals. This species is hunted for human consumption and thus transmission of disease to humans cannot be excluded. To cover a broad spectrum of serogroups, a mixture of the lipopolysaccharides (LPS) of S. typhimurium and S. choleraesuis was used as the antigen in this pilot study. Chicken anti-harp-seal immunoglobulin horseradish peroxidase conjugate served as the immunoconjugate. Sera from four captive harp seals, which were Salmonella culture-negative and had no clinical or historical evidence of salmonellosis, were used as negative controls. After immunization with an inactivated S. typhimurium vaccine, further sera from these seals were used as positive controls, as no serum from naturally infected animals was available. Serum samples from 93 harp seals caught in the Greenland sea in 1999 were examined, and anti-Salmonella antibodies were found in the samples from two individuals (seroprevalence 2.2%). Although Salmonella has been isolated from other pinniped species, this is the first documentation of Salmonella-seropositive harp seals. This study contributes to the evaluation of the importance of salmonellosis in arctic marine mammals and thus to the prevention of potential outbreaks of this important zoonosis.     

Effect of age on reference intervals of serum biochemical values in kittens

OBJECTIVE: To determine the effect of age on reference intervals of serum biochemical values in kittens. DESIGN: Prospective clinical trial. ANIMALS: 55 kittens from 12 specific-pathogen-free queens. PROCEDURE: Kittens were allocated at birth into colostrum-fed (n = 27) and colostrum-deprived (28) groups. Blood was collected at birth and on days 1, 2, 4, 7, 14, 28, and 56. Serum samples were analyzed for activities of alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, creatine kinase, lactate dehydrogenase, gamma-glutamyltransferase, amylase, and lipase and for concentrations of albumin, total protein, bilirubin, urea nitrogen, creatinine, cholesterol, glucose, calcium, phosphorus, and triglycerides by use of an automated analyzer. Total serum solids concentrations were determined by use of refractometry. Serum IgG concentrations were quantified by use of radial immunodiffusion. RESULTS: For several analytes, reference intervals changed rapidly, most notably during the first few days of life. Reference intervals for alkaline phosphatase, creatine kinase, lactate dehydrogenase, and triglycerides were higher from birth to 8 weeks than adult reference intervals. Aspartate aminotransferase, bilirubin, urea nitrogen, and creatinine were higher than in adults at birth but were similar to or lower than adult reference intervals by 8 weeks. Compared with adult reference intervals, reference intervals for calcium and phosphorus concentrations were higher and for albumin and total protein concentrations were lower throughout the study period. CONCLUSIONS AND CLINICAL RELEVANCE: Important differences exist between reference intervals for serum biochemical values of neonatal and adult cats. Age-appropriate reference intervals should be used for accurate assessment of serum biochemical test results in cats.     

Serum chemistry values for free-ranging ringed seals (Pusa hispida) in Svalbard

BACKGROUND: Diseases and abnormal physiologic conditions can alter the concentrations of enzymes, metabolites, minerals, and hormones in the blood of animals. The ringed seal (Pusa hispida) has been selected as a key species for environmental monitoring, but information on disease and health parameters for this species is scarce. OBJECTIVES: The aim of the study reported here was to obtain serum chemistry reference intervals for free-ranging ringed seals in Svalbard, and then to evaluate serum chemistry values in relation to age, body condition, and sex. METHODS: Blood samples were collected after death from ringed seals in Wijdefjorden and Billefjorden, Svalbard (2002-2003; n = 75). Serum was analyzed for 24 selected serum chemistry parameters (enzymes, protein, metabolites, minerals, and cortisol). RESULTS: Compared with younger or older animals, seals between 7 and 16 years of age had larger variations in the activities of alanine transaminase, aspartate transaminase, lactate dehydrogenase, and creatine kinase (CK). Animals classified as having low body condition status had more variation in the serum activity of these enzymes, compared with that in animals with higher condition scores. Serum cortisol concentration was higher in young animals (1-5 years) than in older animals. Serum CK activity was higher in males than in females. CONCLUSION: The data reported here may be useful in monitoring the health of ringed seals and for tracking the impact of environmental changes in the Arctic.     

Tuberculosis in wild seals and characterisation of the seal bacillus

SUMMARY Tuberculosis was diagnosed in 3 otariid seals found dead on beaches at 3 locations on the south coast of Western Australian between May 1990 and March 1991. This confirms that tuberculosis is present in the 2 native seals (Neophoca cinerea and Arctocephalus forsteri) in Western Australian waters. Mycobacterium sp isolated from the lungs of 2 of the seals were studied to determine the similarity of the strains to each other, to the strains isolated during 1986 from Australian sea lions and New Zealand fur seals kept in captivity at a marine park near Perth, Western Australia, and to a strain isolated in 1988 from a seal trainer who worked with the infected captive seals for 3 years. After restriction endonuclease analysis (REA) with the endonucleases Bst Ell, Bcl I and Pvu II, one of the wild seal strains appeared to have identical DNA fragment patterns to the strains from the captive seals and the seal trainer. The other wild seal isolate had identical REA profiles using Bst EII and Bcl I, but a minor difference was detected using Pvu II. Differences in these isolates were more clearly seen in restriction fragment length polymorphisms after hybridisation with two DNA probes. The secretory protein MPB70, present in M bovis, was not detected in wild seal isolates using sodium dodecyl sulphate polyacrylamide gel electrophoresis and Western blotting techniques. Analysis of protein and DNA fragment profiles indicated that seal tuberculosis isolates form a unique cluster within the M tuberculosis complex.     

Serological survey of pre-weaned New Zealand fur seals (Arctocephalus forsteri) for brucellosis and leptospirosis

AIM: To conduct a longitudinal serological survey for evidence of Brucella spp and Leptospira spp infection of pre-weaned New Zealand fur seals in a colony on the Otago Peninsula.

METHODS: Seal pups were repeatedly captured on a monthly basis from February through to July 2001. Pups were tagged at first capture and a blood sample was taken at each capture event. A total of 163 sera were collected from 118 seal pups. Where sufficient volume was collected, the sera were tested for leptospirosis using the microscopic agglutination test (MAT), and for brucellosis using the competitive enzyme-linked immunosorbent assay (ELISA) for Brucella abortus.

RESULTS: None of 128 sera from 101 seals tested positive to the ELISA for B. abortus. All tests for Leptospira interrogans serovars Grippotyphosa, Copenhageni, Bratislava and Leptospira borgpetersenii serovar Ballum were negative at a cut-off of <1/100 dilution. Positive or suspicious titres were found to L. interrogans serovars Canicola and Pomona and L. borgpetersenii serovar Hardjo. The highest titres (12,800) were found to serovar Pomona. The titre to serovar Pomona in one seal rose from <1/50 in March to 12,800 in April and was <1/50 when re-sampled in July. The titre to serovar Pomona in another seal dropped from 12,800 in May to <1/50 in June. These seals also had titres to serovar Hardjo, which rose or fell in the same manner. All suspicious or positive titres occurred in late April and early May, when the pups were approximately 4–5 months old. In June and July, all seals tested were negative.

CONCLUSIONS: There was no serological evidence of Brucella infection in the pre-weaned fur seals at the colony. Positive titres to serovars Pomona, Hardjo, or Canicola suggest that a Leptospira species was present at the colony, however isolation or visualisation of the organism is required to confirm this. Care should be exercised when handling New Zealand fur seals to prevent human infection or inadvertent transfer of leptospirosis to another marine mammal species.     

Evidence of Brucella infection in marine mammals in the North Atlantic Ocean.

Between 1983 and 1996 a total of 1386 samples of serum were taken from four species of seal and three species of whale in the waters west of Iceland, the area of pack-ice north-west of Jan Mayen, the northern coast of Norway and the Kola Peninsula, the waters west of Svalbard, and the Barents Sea; they were tested for the presence of anti-Brucella antibodies with an indirect ELISA (protein G conjugate). The positive sera were re-tested with classical brucellosis serological tests, such as the serum agglutination test, the EDTA-modified serum agglutination test, the Rose Bengal test, and the complement fixation test, as well as an anti-complement ELISA. Anti-Brucella antibodies were detected in all the species investigated, except for the bearded seal (Erignathus barbatus), with the following prevalences: hooded seals (Cystophora cristata) 35 per cent; harp seals (Phoca groenlandica) 2 per cent; ringed seals (Phoca hispida) 10 per cent; minke whales (Balaenoptera acutorostrata) 8 per cent; fin whales (Balaenoptera physalus) 11 per cent; and sei whales (Balaenoptera borealis) 14 per cent. An isolate belonging to the genus Brucella was obtained from the liver and spleen of one of the seropositive minke whales. The findings suggest that antibodies against the surface lipopolysaccharide of Brucella species are widely distributed among marine mammals in the North Atlantic Ocean.     

The effects of two dosages of midazolam on short-duration anesthesia in the harp seal (Phoca groenlandica).

The purpose of this study was to provide safe anesthesia for bronchoalveolar lavage and assess the utility of premedication with i.m. midazolam for short-duration anesthesia with isoflurane in harp seals (Phoca groenlandica). Fourteen yearling harp seal pups were anesthetized three times each as part of a prospective, cross-over, blinded study. Each animal received i.m. premedication with saline, low-dose, or high-dose midazolam (respectively 0.1 and 0.2 mg/ kg). Following premedication, anesthesia was induced with 4% isoflurane in oxygen delivered through a mask and connected to a Bain non-rebreathing system. A significantly longer time was taken from the end of general anesthesia to head movement in the high-dose group compared with the saline group (P = 0.002). A significantly longer time was taken from the end of general anesthesia to ambulation in the high-dose group compared with the saline group (P = 0.006). There were no significant differences between groups in the subjective assessment of anesthetic quality or ease of intubation. Premedication with i.m. midazolam at the dosages used did prolong recovery from anesthesia, although to a degree unlikely to be significant clinically.     

Analysis of blood gases,serum fat and serum protein: a new approach to estimate survival chances of stranded Harbor seal (Phoca vitulina) pups from the German North Sea

Background

Facing numerous challenges, such as illness, storms or human disturbance, some harbor seal (Phoca vitulina) pups lose contact to their dams and are found abandoned along the North Sea coast. In Schleswig-Holstein, pups with the prospect of surviving rehabilitation are admitted to the Seal Center Friedrichskoog. Despite elaborate clinical health assessments on admission, including differential hematology, in 2010, 17% of 108 admitted pups did not survive the first 20 days. The death rate during the years 2006 and 2009 varied between 9 and 19%. To broaden the spectrum of variables which could be predictive for survival, blood gas and serum analyses were performed for 99 pups using venous blood. Variables included total CO₂, pH, partial CO₂, HCO₃^–, base excess and anion gap as well as glucose, urea nitrogen, sodium, potassium and chloride. Moreover, total serum protein and fat (triglyceride) concentrations were measured for all pups on admission.

Results

Repeated measurements of 12 randomly selected individuals revealed a significant (p = 0.002) positive influence of time in rehabilitation on triglyceride concentrations. This trend probably shows the improvement of the pups’ nutritional status as a consequence of the shift from milk replacer formula to fish. No such positive influence was detected for total protein concentrations though. Hematologic values, including blood gases, were not predictive for survival.

Conclusions

For the first time blood gas values are reported in this study for a large sample size (N = 99) of seal pups (regardless of their health status). The ranges and medians calculated from the data can serve as a stepping stone towards the establishment of reference values for neonate harbor seals. However, future investigations on the development of blood gases in harbor seals with different health conditions and ages over time are necessary to allow for a better understanding of acid–base regulation in harbor seals.     

Influence of age,sex, capture technique,and restraint on hematologic measurements and serum chemistries of wild California sea otters

Hematologic and/or serum chemical analyses were done on a total of 27 non-tranquilized adult and juvenile wild sea otters, 66 tranquilized adult and juvenile wild sea otters, and 26 wild sea otter pups. The median and inner 90 percentile range were determined for the adult, juvenile, and pup groups and for the following subgroups: adult male versus adult female, juvenile male versus juvenile female, pup male versus pup female, captured with dip net versus captured with Wilson trap, and tranquilized adults and juveniles versus non-tranquilized adults and juveniles. When values for adults were compared to values for juveniles and pups, hematocrits, red blood cell counts, and hemoglobin levels were significantly lower in pups. This is consistent with documented findings in other species. White cell counts were also somewhat lower in younger animals. Among the subgroups, significantly higher hemoglobin levels, white cell counts and neutrophil counts were found in adult females than in adult males. This is in direct contrast to what is seen in other mammalian species and warrants further documentation. Method of capture and tranquilization did not appear to influence either hematologic or serum biochemical determinations from a clinical perspective.     

Canine motor neuron disease: clinicopathologic features and selected indicators of oxidative stress

Hereditary canine spinal muscular atrophy (HCSMA) is an inherited motor neuron disease affecting a kindred of Brittanies. We have examined the clinicopathologic abnormalities in 57 animals with HCSMA, including 43 affected adult dogs and 14 homozygote pups. We also measured selected biochemical indices of oxidative stress: serum vitamin E (alpha-tocopherol) and Se concentrations; serum concentrations of Cu, Zn, Mg, and Fe; and total superoxide dismutase and glutathione peroxidase activities in red blood cells. Dogs with HCSMA had the following abnormalities: regenerative anemia, hypoglobulinemia, hypochloremia, and abnormally high creatine kinase and liver alkaline phosphatase activities. Serum Cu concentration was significantly (P = .01) increased in adult dogs with HCSMA compared to control dogs. Serum vitamin E concentrations tended to be lower in adult dogs with HCSMA compared to controls, and were significantly (P = .01) lower in homozygote pups compared to control pups.     

Hematologic and serum biochemical reference values for the wild Spectacled Caiman, Caiman crocodilus crocodilus, from the Venezuelan plains

Background: Commercial farming of Caiman crocodilus crocodilus has had an impact on the use of this species for meat consumption and the leather industry. Spectacled Caimans comprise part of the South American plains biodiversity. Misinterpretation of laboratory data is a risk owing to the limited hematologic and serum biochemical values available for this species. Objective: The aim of this study was to determine hematologic and serum biochemical values for wild Spectacled Caimans from the Venezuelan plains. Methods: Blood samples were collected form the caudal tail vein of 100 Spectacled Caimans (40 males and 60 females) from the plains located in the State of Apure. Values for RBC count, PCV, hemoglobin concentration, WBC absolute and differential counts, and thrombocyte counts were obtained using manual methods, and RBC indices were calculated. Serum biochemical analysis included measurement of alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, and creatine kinase activities and concentrations of total protein and albumin. Comparisons between sexes were analyzed using the Mann–Whitney test. Results: Reference values for wild Spectacled Caimans were determined. Minor differences in hematologic values, particularly for RBC counts, were found compared with previously published values for this species. Serum biochemical values were similar to those available for other crocodilians. There were no significant differences between males and females. Conclusions: Minor differences between the values obtained for wild Spectacled Caimans and those previously published for this species may be related to differences in methodology and environmental conditions. Availability of hematologic and serum biochemical reference values will be useful for accurate diagnosis and management of disease in this species.     

Comparison of the somatotropic axis in free-ranging and rehabilitated harbor seal pups (Phoca vitulina)

The somatotropic axis, including growth hormone (GH), insulin-like growth factor (IGF)-I, and IGF binding proteins (IGFBP), is a bridge between growth physiology, developmental age, and nutritional status in domestic animals. However, the importance of the somatotropic axis in nutrition, growth, and development of harbor seals has not been previously explored. Given the difficulty of conducting longitudinal studies in free-ranging harbor seals, this study focused on the potential use of harbor seals in rehabilitation facilities as a model for free-ranging seals. The purpose of this research was to compare concentrations of components of the somatotropic axis in free-ranging versus rehabilitated harbor seal pups. The hypothesis was that measurements of the somatotropic axis will be similar between individuals of comparable age and nutritional status (fasting versus feeding). To investigate this hypothesis, harbor seal pups (n=8) brought to The Marine Mammal Center (Sausalito, California, USA) or Mystic Aquarium (Mystic, Connecticut, U.S.A.) were initially assessed and determined to be healthy but abandoned. All pups were less than 2 wk of age upon arrival at rehabilitation facilities. Standard length was assessed at the time of arrival and again at release. Body mass was measured every week and blood samples were collected from each pup at 0, 4, and 8 wk of rehabilitation. Blood was collected and morphometrics assessed in free-ranging harbor seal pups (n=8) from the Gulf of Maine. Sera were analyzed for GH, IGF-I, and IGFBP concentrations. Concentrations of GH, IGF-I, and IGFBP-2 and -3 in rehabilitated pups were within a similar range compared with free-ranging pups when considered in the context of presumed nutrient intake. These data suggest that rehabilitated harbor seals may provide a useful model to investigate the effects of nutrient intake on growth and development of harbor seals, and will provide insight into phocid endocrinology and metabolism.     

The transmission of phocine herpesvirus-1 in rehabilitating and free-ranging Pacific harbor seals (Phoca vitulina) in California

Phocine herpesvirus-1 (PhHV-1) causes regular outbreaks of disease in neonatal harbor seals (Phoca vitulina) at rehabilitation centers in Europe and in the U.S. To investigate transmission of this virus samples were collected from harbor seal pups during exposure studies at a Californian rehabilitation center from 1999 to 2002 and from free-ranging harbor seals off central California during the same period. The exposure studies provided evidence that PhHV-1 can be transmitted horizontally between animals most likely through direct contact with oro-nasal secretions. However vertical transmission may also occur, as adult female harbor seals were found to be shedding the virus in vaginal and nasal secretions, and premature newborn pups had evidence of early infection. Results also indicated that PhHV-1 infections were common in both free-ranging (40%, 49/121) and rehabilitating (54%, 46/85) young harbor seals, during the spring and early summer. This timing, which correlated with pupping and weaning, suggested that the majority of animals were infected and infective with PhHV-1 between pupping and breeding.     

Longitudinal study of northern fur seal (Callorhinus ursinus) hematology

Although the causes have not been specified yet, wild populations of northern fur seals (Callorhinus ursinus) have been decreasing, which is why conservation techniques such as captive breeding and health maintenance should be established. Hematological parameters can be used to maintain the health status of northern fur seals kept in captivity for artificial reproduction and public education. Year-round fluctuations of blood parameters have not been examined for northern fur seals due to the difficulties in obtaining serial blood samples from wild animals during the oceanic migration period from late autumn to spring. In this study, blood samples were collected from four captive northern fur seals and analyzed monthly for more than three years to clarify the seasonal fluctuation patterns in 14 hematological parameters. Many hematological parameters seemed to be seasonal patterns: summer–autumn and winter–spring; leukocyte-related parameters were higher in summer and autumn than in winter and spring; erythrocyte-related parameters were lower in summer and autumn than in winter and spring. Significant seasonal differences in nine of the 14 parameters were observed using a generalized linear mixed model (GLMM) analysis. These results have improved our understanding of the seasonal patterns of hematological characteristics in the northern fur seal and can contribute to the health care of protected or captive northern fur seals.     

Antigenic characterization of mycobacteria from South American wild seals.

Tuberculosis-producing mycobacteria have been previously described in marine mammals (Cousins et al., 1990, 1993; Romano et al., 1995; Bernardelli et al., 1996). The strains belonged to the M. tuberculosis complex (M. tuberculosis, M. bovis, M. microti and M. africanum), but showed genetic and biochemical differences. The antigenic composition of mycobacteria isolated from wild seals was analyzed by Western blots, using antibodies against some selected antigens. The antigenic content was compared with that of M. bovis, M. tuberculosis and M. microti isolates. The lack of Hsp65 protein in supernatants suggested a low degree of cell lysis in the three-week cultures used. SOD, P27 lipoprotein, MPB64 and antigen 85 were observed in all the strains studied. The wild seal strains, as well as M. tuberculosis, did not produce MPB70 and MPB83. Only very weak bands of P36 antigen were observed in culture supernatants from wild seal mycobacteria. Summarizing, the antigenic composition of mycobacterial strains from wild seals is different from M. bovis strains.     

Serological survey of pre-weaned New Zealand fur seals (Arctocephalus forsteri) for brucellosis and leptospirosis

AIM: To conduct a longitudinal serological survey for evidence of Brucella spp and Leptospira spp infection of pre-weaned New Zealand fur seals in a colony on the Otago Peninsula. METHODS: Seal pups were repeatedly captured on a monthly basis from February through to July 2001. Pups were tagged at first capture and a blood sample was taken at each capture event. A total of 163 sera were collected from 118 seal pups. Where sufficient volume was collected, the sera were tested for leptospirosis using the microscopic agglutination test (MAT), and for brucellosis using the competitive enzyme-linked immunosorbent assay (ELISA) for Brucella abortus. RESULTS: None of 128 sera from 101 seals tested positive to the ELISA for B. abortus. All tests for Leptospira interrogans serovars Grippotyphosa, Copenhageni, Bratislava and Leptospira borgpetersenii serovar Ballum were negative at a cut-off of <1/100 dilution. Positive or suspicious titres were found to L. interrogans serovars Canicola and Pomona and L. borgpetersenii serovar Hardjo. The highest titres (12,800) were found to serovar Pomona. The titre to serovar Pomona in one seal rose from <1/50 in March to 12,800 in April and was <1/50 when re-sampled in July. The titre to serovar Pomona in another seal dropped from 12,800 in May to <1/50 in June. These seals also had titres to serovar Hardjo, which rose or fell in the same manner. All suspicious or positive titres occurred in late April and early May, when the pups were approximately 4-5 months old. In June and July, all seals tested were negative. CONCLUSIONS: There was no serological evidence of Brucella infection in the pre-weaned fur seals at the colony. Positive titres to serovars Pomona, Hardjo, or Canicola suggest that a Leptospira species was present at the colony, however isolation or visualisation of the organism is required to confirm this. Care should be exercised when handling New Zealand fur seals to prevent human infection or inadvertent transfer of leptospirosis to another marine mammal species.     

Preliminary investigation of a possible lung worm (Parafilaroides decorus), fish (Girella nigricans), and marine mammal (Callorhinus ursinus) cycle for San Miguel sea lion virus type 5

Colostrum-deprived neonatal Northern fur seal pups (Callorhinus ursinus) were exposed to San Miguel sea lion virus type 5 (SMSV-5) by feeding them fish (Girella nigricans) infected with virus or fish infected with both the sea lion lung worm larvae (Parafilaroides decorus) and virus. Virus infection was demonstrated in 8 of 9 pups, and 1 of these developed a vesicular lesion on the flipper. In this sequence, P decorus larvae exposed to SMSV-5 were fed to G nigricans held at 15 C in a salt water aquarium; 32 days later, these fish were killed, then fed to the fur seal pups. The vesicle developed 22 days subsequent to this and SMSV-5 was reisolated from the lesion. The SMSV-5 was shown to persist for at least 23 days in infected neonatal fur seals. Attempts to establish P decorus infection in Northern fur seal pups were apparently unsuccessful.     

Survival versus nonsurvival determinants for neonatal harbor seals

Of 29 neonatal harbor seals that had been abandoned, separated from their mothers, or stranded in the wild, 22 succumbed during hospitalization at the California Marine Mammal Center in the spring of 1982. Compared with standard reported harbor seal pup measurements, 8 of the nonsurviving pups were premature (ie, creamy-white lanugo coat, early pupping season birthdate, and decreased body size [6 to 10 cm shorter and 2.3 to 4.5 kg less than normal]). The premature pups and the young pups (less than or equal to 10 days old) had at least two of the following findings: jaundice, emaciation, labored respiration, hyperbilirubinemia, hypoglobulinemia, or leukopenia. Most of the nonsurviving pups died within 96 hours after admission. Macroscopic and microscopic findings indicated that a high percentage of these pups had pulmonary congestion and edema (72.7%), alveolar squamous cells/debris (27.3%), and/or congenital cardiac anomalies (ie, patent ductus arteriosus [63.6%] and patent foramen ovale [45.4%]). Two older pups (greater than 10 days old) died from chronic bacterial infections, accompanied by adrenal cortical hyperplasia. The 7 surviving pups had adult spotted pelage, normal body weights (9 to 11 kg), normal globulin concentrations (3.0 to 5.1 g/dl), and normal WBC counts (7 to 9 X 10(3)/microliters) and did not have clinical signs of icterus or respiratory distress.     

Rearing and rehabilitation of common seal pups (Phoca vitulina)

Veterinary surgeons may be presented with seal pups that require rearing and rehabilitation. This paper describes the feeding, weight gains and clinical care of 22 harbour or common seal pups (Phoca vitulina) that were reared and rehabilitated at the RSPCA Seal Assessment Unit in Norfolk during 1989. Eighteen of the seals survived and were released but four died. On arrival the pups' mean (+/- sd) bodyweight was 9.2 +/- 2.1 kg; those which survived stayed an average of 14.2 +/- 2.3 weeks before they were released at an average weight of 35.5 +/- 3.5 kg.     

斑海豹的人工繁殖和饲养管理

以40头斑海豹（雌兽21头,雄兽19头）为研究对象,从2006年开始进行斑海豹的人工繁育试验。2008年、2009年和2010年分别成功繁育了2头、7头和8头斑海豹,成活率分别为33.3%,70.0%和66.6%。同时,对人工饲养条件下斑海豹的繁殖条件、孕期管理、产前饲养和生产过程管理及幼海豹人工填食、驯化等方面进行了总结。描述了斑海豹的不同时期的形态和行为变化,并介绍了斑海豹人工繁殖的优化条件。为提高斑海豹人工繁育成活率、建立合理的饲养管理标准提供了基础资料。