Microsatellites from the beluga whale Delphinapterus leucas

Fifteen microsatellites were isolated from a beluga whale Delphinapterus leucas , genomic library. The microsatellites were amplified in 100 beluga obtained from two widely separated locations. An average of 8.6 alleles per locus were detected and the average heterozygosity was 0.65 with a range of 0.27–0.86. All microsatellites were polymorphic and 13 of the genotype distributions observed were in Hardy-Weinberg equilibrium. It was possible with these microsatellites to assign correctly individual whales to their stock-of-origin 98% of the time. Microsatellites were amplified in 15 other cetaceans with these beluga-derived primers.     

Anatomy of the heart of the beluga whale (Delphinapterus leucas)

The heart of the beluga whale (Delphinapterus leucas) is described from the dissection of seven specimens. As in most whales the heart is characterized by a transverse broadness and a flatness of the ventricles from one surface to the other and by an apex formed by both ventricles. Heart size parameters are used for comparison with parameters of other marine and land mammals. The heart width index (heart height/heart circumference) averages 31.3 in comparison to 28.7 for the Weddell seal and 39.0 for the felids. The right ventricle is relatively long and narrow with a mean length index (TS/heart height) of 64.7 and a mean breadth index (TP/heart height) of 38.7. These heart parameters are discussed in functional terms.     

Herpes-like viral dermatitis in a beluga whale (Delphinapterus leucas)

Approximately 3.5 mo following its capture, a beluga whale (Delphinapterus leucas) developed focal pale gray skin lesions. These lesions persisted for at least 8 mo. A biopsy from one of these sites revealed epithelial intranuclear inclusions. Herpes-like viral particles were seen by transmission electron microscopy. The eventual regression of skin lesions and lack of other clinical signs suggests the virus was only mildly pathogenic in this animal.     

Parental behavior of the beluga whale (Delphinapterus leucas) in natural environment

The parental behavior of beluga whales observed in a summer reproductive gathering (near Solovetsky Island, Onega Bay, White Sea) is described, including the parturition process. A tight association between the female and its newborn infant has been traced by the case study of a stillborn calf. Individual behavioral patterns of a mother and calves observable only in natural habitats are detailed.     

Nucleotide sequence of the p53 cDNA of beluga whale (Delphinapterus leucas)

The cDNA (DNA complementary to RNA) of the p53 gene of the beluga whale (Delphinapterus leucas) was sequenced by the method of 5'- and 3'-rapid amplification of cDNA ends (RACE) with the cDNA made for the RNA obtained from fresh peripheral blood leukocytes isolated from two animals. Primers for the RACE method were synthesized based on the sequence of the DNA of beluga whale corresponding to exon 5 of the human p53 gene, which was determined after amplification of the DNA isolated from the liver from a beluga whale by using a pair of primers for the human sequence. The sequenced cDNA had a 2150-nucleotide length and contained the whole region corresponding to human exons 1 through 11. The reading frame was 1164 bp (base pair) long and began in exon 2 and ended in exon 11, coding for a 387-amino acid protein. The nucleotide sequence of the reading frame showed high similarity over 85% with pig, sheep, cow, and human genes. The similarities with the former two animals at the amino acid level were also more than 85%. Lower similarity of the beluga whale p53 gene was also found with those of lower tetrapods, fish and invertebrates.     

Arterial and venous vasculature of the heart of the beluga whale (Delphinapterus leucas)

The arteries and veins of the heart of the beluga whale (Delphinapterus leucas) are described from the dissection of nine specimens. The arterial distribution is composed of the basic mammalian pattern of two major vessels, the left and right coronary arteries, which supply the cardiac tissue. The venous drainage is provided by three major systems which are the great, middle, and small cardiac veins. The vascular characteristics of the heart of the beluga whale are the marked sinuosity of both coronary arteries and their main branches, the numerous large interarterial anastomoses between major vessels, and the duplication of vessels in parallel branches. These characteristics are discussed in functional terms and correlated with the diving ability of the species.     

Successful treatment of suspected erysipelas septicemia in a beluga whale (Delphinapterus leucas)

A 20-year-old male beluga whale (Delphinapterus leucas) was diagnosed with suspected acute septicemic erysipelas. Physical examination was unremarkable and no skin lesions were evident. Hematologic and serum biochemical abnormalities included mild anemia, a marked leukocytosis, an increase in the erythrocyte sedimentation rate, and moderate elevations of total protein, gamma globulins, blood urea nitrogen, and creatinine. Microtitration agglutination testing for Erysipelothrix rhusiopathiae antibodies revealed seroconversion and elevated antibody titers associated with the clinical illness, presumptive evidence of an active E. rhusiopathiae infection. Treatment consisted of oral fluids, cimetidine, and a 25-day course of ciprofloxacin hydrochloride. The whale made a rapid and uneventful recovery. None of the three female beluga whales that shared the pool with the ill male, nor male and female beluga whales maintained in a separate pool, became ill or showed serologic evidence of E. rhusiopathiae exposure. © 1993 Wiley-Liss, Inc.     

Phylogeography, population structure and dispersal patterns of the beluga whale Delphinapterus leucas in the western Nearctic revealed by mitochondrial DNA

The recent evolutionary history, population structure and movement patterns of beluga whales in the western Nearctic were inferred from an analysis of mitochondrial DNA control region sequence variation of 324 whales from 32 locations representing five summer concentration areas in Alaska and north-west Canada. Phylogenetic relationships among haplotypes were inferred from parsimonious networks, and genetic subdivision was examined using haplotypic frequency-based indices and an analysis of variance method modified for use with interhaplotypic distance data. MtDNA relationships were characterized by a series of star-like phylogenies which, when viewed in conjunction with information on haplotype frequency and distribution, suggested a rapid radiation of beluga whales into the western Nearctic following the Pleistocene, and an early divergence of the Beaufort Sea from the Chukchi and Bering Seas subpopulations. Overall nucleotide diversity was low (0.51%) yet all major summering concentrations were significantly differentiated (Φ_ST= 0.33) from one another. Stratification of samples by gender and age from the three northernmost subpopulations suggested that female cohorts from neighbouring subpopulations were more differentiated than males. Further stratification of adult animals by age revealed that older adults were substantially less subdivided among locations than younger adults, particularly for males, suggesting that dispersal, although limited, is biased toward older adult males. Overall, the patterns of mtDNA variation in beluga whales indicated that the summering concentrations are demographically, if not phyletically distinct. Population structure appears to be maintained primarily by natal homing behaviour, while asymmetries in dispersal may be associated with the type of mating system.     

A microscopic investigation of the lymphoid organs of the beluga,Delphinapterus leucas

Lymphoid organs from belugas, Delphinapterus leucas, ranging in age from less than one to 16 years, were harvested during a sanctioned hunt to investigate morphology. The spleen is divisible into red and white pulp and a stroma consisting of a reticular network, a collagenous capsule, and trabeculae containing smooth muscle bundles. White pulp areas appear to be devoid of follicles and consist mainly of periarteriolar lymphatic sheaths (PALS), that are larger in younger than in older belugas. Definitive marginal zones between red and white pulp are difficult to discern in older belugas. Lymph nodes are similar to those of other mammals; they possess a follicular cortex surrounding a vascular medulla composed of lymphatic cords and sinuses. Smooth muscle is abundant in the medullary region, usually in close proximity to sinuses. The expansive nodular mass at the root of the mesentery, often referred to as the “pseudopancreas,” is similar to lymph nodes in microscopic architecture. Pharyngeal tonsils and gut-associated lymphoid tissue (GALT) are found along the digestive tract and display an “active” morphology. Tonsils are comprised of lobules of follicles separated by vascular connective tissue. Epithelial-lined crypts communicate with the pharyngeal lumen. GALT consists of diffuse and follicular lymphocytes within the intestinal mucosa and submucosa. The thymus is well developed in the younger belugas, with lobules divisible into densely packed cortical zones of thymocytes and more loosely arranged medullary lymphocytes. Hassall's corpuscles are occasionally visible within the medulla. Cetaceans diverged evolutionarily from other mammals over 55 million years ago. This study investigates changes in lymphoid organ morphology in a species that now inhabits a unique ecological niche. This study also lays the groundwork for functional investigation of the beluga immune system, particularly as it relates to differences between healthy and stranded animals. © 1993 Wiley-Liss, Inc.     

Chemical characterization of the oligosaccharides in beluga (Delphinapterus leucas) and Minke whale (Balaenoptera acutorostrata) milk

Carbohydrates were extracted from the milk of a beluga, Delphinopterus leucas (family Odontoceti), and two Minke whales, Balaenoptera acutorostrata (Family Mysticeti), sampled late in their respective lactation periods. Free oligosaccharides were separated by gel filtration and then neutral oligosaccharides were purified by preparative thin layer chromatography and gel filtration, while acidic oligosaccharides were purified by ion-exchange chromatography, gel filtration and high performance liquid chromatography (HPLC). Their structures were determined by 1H-NMR. In one of the Minke whale milk samples, lactose was a dominant saccharide, with Fuc(alpha1-2)Gal(beta1-4)Glc(2'-fucosyllactose), Gal(beta1-4)GlcNAc(beta1-3)Gal(beta1-4)Glc(lacto-N-neotetraose), GalNAc(alpha1-3)[Fuc(alpha1-2)]Gal(beta1-4)Glc(A-tetrasaccharide), Gal(beta1-4)GlcNAc(beta1-3)Gal(beta1-4)GlcNAc(beta1-3)Gal(beta1-4)Glc (para lacto-N-neohexaose), Neu5Ac(alpha2-3)Gal(beta1-4)GlcNAc(beta1-3)Gal(beta1-4)Glc (sialyl lacto-N-neotetraose), Neu5Ac(alpha2-6)Gal(beta1-4)GlcNAc(beta1-3)Gal(beta1-4)Glc (LST c) and Neu5Ac(alpha2-3)Gal(beta1-4)GlcNAc(beta1-3)Gal(beta1-4)GlcNAc(beta1-3)Gal(beta1-4)Glc (sialyl para lacto-N-neohexaose) also being found in the milk. The second Minke whale sample contained similar amounts of lactose, 2'-fucosyllactose and A-tetrasaccharide, but no free sialyl oligosaccharides. Sialyl lacto-N-neotetraose and sialyl para lacto-N-neohexaose are novel oligosaccharides which have not been previously reported from any mammalian milk or colostrum. These and other oligosaccharides of Minke whale milk may have biological significance as anti-infection factors, protecting the suckling young against bacteria and viruses. The lactose of Minke whale milk could be a source of energy for them. The beluga whale milk contained trace amounts of Neu5Ac(alpha2-3)Gal(beta1-4)Glc(3'-N-acetylneuraminyllactose), but the question of whether it contained free lactose could not be clarified. Therefore, lactose may not be a source of energy for suckling beluga whales.     

Hematology and serum chemistry values in the beluga (Delphinapterus leucas)

Normal values and ranges for 31 clinical hematology and serum chemistry tests are reported for the beluga or white whale (Delphinapterus leucas). The values were collected over a 6-yr period from eight belugas maintained for display at Sea World (San Diego, California, USA) facilities and represent long-term evaluations for each animal in a controlled environment. They represent the first report for a number of serum chemistry values for the beluga. Normal values such as these provide an important data base from which to detect diagnostically important changes in health status for belugas in a zoological setting. They also establish a baseline from which to evaluate differences in normal values in free-ranging belugas and from which to diagnose disease problems in wild populations.     

Bartonella henselae in captive and hunter-harvested beluga (Delphinapterus leucas)

Previously, we reported the isolation of Bartonella henselae from the blood of harbor porpoises (Phocoena phocoena) and loggerhead sea turtles (Caretta caretta) from the North Carolina coast. Hematologic, pathologic, and microbiologic findings surrounding the death of a juvenile captive beluga in Vancouver initiated an outbreak investigation designed to define the molecular prevalence of Bartonella infection in belugas. Using polymerase chain reaction analyses targeting the intergenic spacer region (ITS), two B. henselae ITS strains were identified in 78% of captive and free-ranging hunter-harvested belugas. These findings may have public health implications and may influence aquarium management procedures for captive marine mammals.     

Movements of beluga whales (Delphinapterus leucas) in Bristol Bay,Alaska

We describe the annual distribution of beluga whales (Delphinapterus leucas) in Bristol Bay, Alaska, using data from 31 satellite‐linked transmitters during 2002–2011. Bristol Bay has one of the largest and best studied Pacific salmon (Oncorhynchus spp.) fisheries in the world, allowing us to link the seasonal distribution of belugas to that of salmon. During salmon migrations, beluga movements were restricted to river entrances. Belugas generally did not relocate to different river entrances or change bays during peak salmon periods. However, the location of belugas was not related to the number of salmon passing counting towers, suggesting that belugas were either selecting locations that were good for catching salmon or there were simply more salmon than belugas needed to supply their nutritional needs. The distribution of belugas expanded after salmon runs ended, and was greatest in winter when belugas ranged beyond the inner bays, traveling as far west as Cape Constantine. Belugas continued to frequent the inner bays in winter whenever sea ice conditions allowed, e.g., when winds moved sea ice offshore; however, they were never located south of the southern ice edge in open water or outside of Bristol Bay.     

Nursing behaviors of beluga calves (Delphinapterus leucas) born in captivity

The nursing behaviors of two beluga whale calves were observed for the first 55 days postpartum. For both calves, the total time spent nursing in a given period peaked around 7–10 days postpartum and then declined over time. One calf, however, was found to have an unusual decline in nursing at day 35 postpartum. Ten days later, this calf was diagnosed as having a bacterial infection and given antibiotics. This suggests that early detection of health problems may be possible by observing calves' nursing behavior. For both calves, their general nursing patterns were similar, although one calf consistently nursed more than the other. Both calves nursed roughly every half hour, neither showed any signs of a circadian pattern, and carryover effects for both calves were found, indicating that there was a relationship in the overall nursing pattern from one interval to the next. That is, if nursing dropped off during one interval, it was typically made up in the next interval. Zoo Biol 16:247–262, 1997. © 1997 Wiley-Liss, Inc.     

The suckling behavior of a captive beluga (Delphinapterus leucas) calf

Observations of suckling activities of a beluga cow and calf were carried out during five 24-h watches from 3 to 38 days of age, and six 12-h watches from 52 to 109 days of age. The calf died at 111 days. No clear circadian pattern of suckling was seen in the first month. At 3 and 52 days of age, the calf intensively suckled another sub-adult female in the pool. Suckling patterns were irregular during the first month and then stabilised. The number of separate suckling attempts fluctuated considerably between ages but the number of suckling bouts were relatively constant.Tail flexing and rubbing of the mammaries on the bottom of the pool indicated that milk can be expelled from the beluga mammary by pressure external to the gland and in the absence of suckling.     

A genetic analysis of the beluga whale Delphinapterus leucas (Cetacea: Monodontidae) from summer aggregations in the Russian Far East

The genetic structure of four summer aggregations of the Beluga Whale, Delphinapterus leucas, in Sakhalin Bay and Udskaya Bay, off the western coast of Kamchatka in the Sea of Okhotsk and in the Anadyr Estuary of the Bering Sea was analyzed through nucleotide sequencing of the mtDNA control region and detection of the allelic composition of nine microsatellite loci in nuclear DNA. It has been shown that each of the aggregations features a unique set of maternal lines, which indicates a high degree of philopatry in this species. Beluga whales of the Anadyr Estuary are genetically isolated from those of the Sea of Okhotsk. Beluga whales of the summer aggregations of Sakhalin Bay and those from Udskaya Bay share a common gene pool and belong to a single population, while the whales that summer off western Kamchatka with great consistency may be attributed to a different population. Comparison of nucleotide sequences of the mtDNA in beluga whales from various waters of the Russian Far East and North America allowed us to propose a hypothesis about how the structure of beluga whale populations formed in the North Pacific during the postglacial period.