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Diversity in sound pressure levels and estimated active space of resident killer whale vocalizations.

Signal source intensity and detection range, which integrates source intensity with propagation loss, background noise and receiver hearing abilities, are important characteristics of communication signals. Apparent source levels were calculated for 819 pulsed calls and 24 whistles produced by free-ranging resident killer whales by triangulating the angles-of-arrival of sounds on two beamforming arrays towed in series. Levels in the 1-20 kHz band ranged from 131 to 168 dB re 1 microPa at 1 m, with differences in the means of different sound classes (whistles: 140.2+/-4.1 dB; variable calls: 146.6+/-6.6 dB; stereotyped calls: 152.6+/-5.9 dB), and among stereotyped call types. Repertoire diversity carried through to estimates of active space, with "long-range" stereotyped calls all containing overlapping, independently-modulated high-frequency components (mean estimated active space of 10-16 km in sea state zero) and "short-range" sounds (5-9 km) included all stereotyped calls without a high-frequency component, whistles, and variable calls. Short-range sounds are reported to be more common during social and resting behaviors, while long-range stereotyped calls predominate in dispersed travel and foraging behaviors. These results suggest that variability in sound pressure levels may reflect diverse social and ecological functions of the acoustic repertoire of killer whales.

Animals↗

Sound transmission in the nose of the sperm whale Physeter catodon. A post mortem study.

During a sperm whale stranding at Rømø, the Wadden Sea, Denmark, on 4 December 1997, we were notified in time to start acoustic transmission measurements in the spermaceti complex 1 h after the specimen was seen alive. Frequency-modulated sound pulses, sweeping from 30 kHz to 10 kHz in 25 ms, were injected at the frontal surface at two positions: at the distal sac, and at the center of the junk (a compartmentalized structure below the spermaceti organ). A hydrophone next to the projector served as receiver. The analyses of the recordings show a repetitive, decaying reflection pattern at both projection sites, reminiscent of the multi-pulse click peculiar to sperm whales, although with minor differences in the duration of the intra-click intervals. This experimental evidence supports the Norris and Harvey (1972) theory of click generation in the spermaceti organ. Accordingly, the click is composed of a primary event, followed by a train of reflected pulses, spaced by the time required for the event to travel back and forth between air sacs (reflectors) at each end of the organ. The results also show that the junk readily transmits sound and probably is in acoustic contact with the spermaceti organ.

Animals↗

Stable carbon and nitrogen isotope ratio profiling of sperm whale teeth reveals ontogenetic movements and trophic ecology.

Teeth from male sperm whales (Physeter macrocephalus) stranded in the North-eastern Atlantic were used to determine whether chronological profiles of stable isotope ratios of C (delta(13)C) and N (delta(15)N) across dentine growth layers could be used to detect known ontogenetic benchmarks in movements and trophic ecology. Profiles showed a general decrease in delta(13)C (median = 1.91 per thousand) and an increase in delta(15)N (median = 2.42 per thousand) with age. A marked decline in delta(13)C occurred for all 11 teeth around 9-10 years and again for six individuals around 20 years. After the early twenties the delta(13)C continued to decline with age for all teeth. These results are consistent with males segregating from natal groups in low latitudes with the onset of puberty between 4 and 15 years and gradually dispersing pole-ward into (13)C-depleted temperate waters. Penetration into further depleted, productive high latitudes after the age of 20 might facilitate the spurt of accelerated growth rate observed around this age. Breeding migrations back to lower latitudes were not reflected in the delta(13)C profiles possibly due to being short compared to the time spent feeding in high latitudes. The timings of marked isotopic change in the delta(15)N profiles reflect those of the delta(13)C profiles, suggesting a link between dietary changes and movements. The observed increase in delta(15)N with age is likely to be caused by a trophic level increase as males grow in size, probably feeding on larger prey. An additional explanation could be that, in the higher latitudes of the North Atlantic, the main prey source is the high trophic level squid Gonatus fabricii. Also, the lower latitudes from where males disperse are depleted in basal (15)N. Profiles of delta(13)C and delta(15)N in sperm whale teeth gathered from different regions, sexes, and periods in time, could provide a unique way to understand the ecology of this species across different oceans.

Age Factors↗

Complete amino acid sequence of the major component myoglobin from the goose-beaked whale, Ziphius cavirostris.

The complete primary structure of the major component myoglobin from the goose-beaked whale, Ziphius cavirostris, was determined by specific cleavage of the protein to obtain large peptides which are readily degraded by the automatic sequencer. Over 80% of the amino acid sequence was established from the three peptides resulting from the cleavage of the apomyoglobin at its two methionine residues with cyanogen bromide along with the four peptides resulting from the cleavage with trypsin of the citraconylated apomyoglobin at its three arginine residues. Further digestion of the central cyanogen bromide peptide with S. aureus strain V8 protease and the 1,2-cyclohexanedione-treated central cyanogen bromide peptide with trypsin enabled the determination of the remainder of the covalent structure. This myoglobin differs from the cetacean myoglobins determined to date at 12 to 17 positions. These large sequence differences reflect the distant taxonomic relationships between the goose-beaked whale and the other species of Cetacea the myoglobin sequences of which have previously been determined.

Amino Acid Sequence↗

Pathology of stranded beluga whales (Delphinapterus leucas) from the St. Lawrence Estuary, Québec, Canada.

From June 1983 to May 1986, thirteen carcasses of stranded beluga whales from a polluted area of the St. Lawrence River, Canada were necropsied. High performance liquid chromatography was performed on the brains of three other animals to determine concentrations of benzo a pyrene (BaP). Two juvenile animals had severe multisystemic lesions one of which, a severe necrotizing dermatitis, was associated with a Herpesvirus-like particle. Four adults had five varieties of tumours. An adult had a systemic nocardiosis and a juvenile was affected ty a non 0:1 Vibrio cholerae septicemia. High concentrations of BaP adducts were found in the brains which were analyzed. Occurrence of BaP adducts in the brain of three whales of this population coincides with the high incidence of tumours. This and the previous finding of high concentrations of organochlorine in the tissues of these animals suggest an important role of industrial contaminants in the recent decrease of this population.

Animal Diseases↗

Hodgkin's disease in a killer whale (Orcinus orca).

Hodgkin's disease (HD) is reported in a killer whale (Orcinus orca). Generalized lymphadenopathy and splenomegaly were noted at necropsy and histopathological examination revealed diffuse proliferation of atypical large cells with huge eosinophilic nucleoli. They were often multinucleated, and binucleated forms characteristic of Sternberg-Reed cells of human HD were occasionally present. There was no cytological atypia in the background lymphocytes. Thus, the lesion was identified as analogous to HD in man. To our knowledge, this is the first recorded case of HD in the killer whale.

Animals↗

Use of immunoadsorbents for the study of antibody binding to sperm whale myoglobin and its synthetic antigenic sites.

Conditions for preparing immunoadsorbents of sperm-whale myoglobin and its five synthetic antigenic sites and for desorption of radiolabeled antibodies from the immunoadsorbents were studied. In immunoadsorbent titration studies, the sum of the amounts of antibodies bound in the plateau (maximum binding) by the adsorbents of the five sites accounted quantitatively for the entire (100%) antibody response to sperm-whale myoglobin.

Animals↗

Interlaboratory comparison study for PCB congeners and chlorinated pesticides in beluga whale blubber.

Three laboratories participated in an interlaboratory comparison exercise for the determination of polychlorinated biphenyl (PCB) congeners and chlorinated pesticides in Standard Reference Material (SRM) 1588 (Organics in Cod Liver Oil) a whale blubber control material, and six beluga whale (Delphinapterus leucas) blubber samples. The results are generally in good agreement. The minor disagreement of some of the results may be attributed to differences in detector calibrations, differences in chromatographic separation selectivity for specific compounds, or both. The SRM and control material help to validate the analytical procedures and to verify that these procedures remain in control.

Adipose Tissue↗

Overview and regional and temporal differences of heavy metals in Arctic whales and ringed seals in the Canadian Arctic.

Concentrations of mercury, cadmium, and other heavy metals in tissues of belugas (Delphinapterus leucas), narwhal (Monodon monoceros) and ringed seals (Phoca hispida) from across the Canadian Arctic are reported. Published and new information is used to provide an overview of metals in tissues of these animals, to delineate the existence of a spatial trend of mercury and cadmium in belugas and ringed seals, and to show a temporal trend is superimposed on the geochemical trend. Mercury concentrations in tissues of Arctic whales and ringed seals were high relative to the Canadian guideline of 0.5 micrograms/g wet wt., for mercury in fish, except in the skin of belugas (0.59-0.78 micrograms/g wet wt.) and flesh of ringed seals (0.39-0.41 micrograms/g wet wt.). In the flesh of belugas (0.94-1.34 micrograms/g wet wt.), and in the liver of ringed seals, tissues that are also consumed by Native people in the Arctic (8.34-27.5 micrograms/g wet wt.), the guideline value was significantly exceeded. Mean lead concentrations in tissues of belugas, narwhal and ringed seals were generally low (0.002-0.028 micrograms/g wet wt.), except in tissues of belugas in the St. Lawrence River (0.10-0.15 micrograms/g wet wt.). The concentration of zinc in the skin of whales was two to three times higher than in other tissues. The concentration of cadmium in organs was highest in narwhal. There was a positive correlation between mercury and selenium in the liver of all three species. The concentration of mercury in tissues of belugas and ringed seals was higher in the western than the eastern Arctic. This was attributed to different natural background concentrations in the western and eastern Arctic of Canada dictated by different geological formations in the two regions. Cadmium concentrations in tissues of belugas and ringed seals were higher in the eastern than the western Arctic. Zinc and copper in some tissues of belugas and ringed seals were also higher in the eastern than the western Arctic. Mercury in the liver of belugas was found to have increased in the western and eastern Arctic over 10-12 years. Mercury in the liver of ringed seals in the western Arctic and narwhal in the eastern Arctic showed similar increases. In recently collected belugas, the rate of accumulation of mercury in the liver was approximately twice that in belugas collected 10-12 years ago. In ringed seals, the rate was three times higher in recent samples compared to 15-20 years ago. There was no temporal change in cadmium levels in tissues of belugas, ringed seals or narwhal.

Analysis of Variance↗

Immune functions in beluga whales (Delphinapterus leucas): evaluation of mitogen-induced blastic transformation of lymphocytes from peripheral blood, spleen and thymus.

A quantitative assay was developed to evaluate mitogen-induced lymphoblastic transformation in beluga whales (Delphinapterus leucas) using peripheral blood mononuclear cells, splenocytes and thymocytes. Optimal concentrations of four different mitogens (Con-A, PHA, LPS and PWM) were determined with the use of standard curves. Addition of human recombinant IL-2 (rhIL-2) after 48 h in culture with the different mitogens suggests that Con-A, PHA and PWM, but not LPS, stimulate T cells in belugas, as they do in other animal species. The addition of 2-mercaptoethanol did not enhance significantly the proliferation of cells stimulated by Con-A, PHA and LPS, while it did with the cells stimulated by PWM and those cultured without mitogen. The proliferative response of cells was suppressed when the culture medium was supplemented by beluga serum instead of fetal calf serum. This assay will be useful to assess the status of the immune functions in different populations of beluga whales as well for further in vitro immunotoxicological experiments.

Animals↗

A comparison of the intrinsic fluorescence of red kangaroo, horse and sperm whale metmyoglobins.

Several metmyoglobins (red kangaroo, horse and sperm whale), containing different numbers of tyrosines, but with invariant tryptophan residues (Trp-7, Trp-14), exhibit intrinsic fluorescence when studied by steady-state front-face fluorometry. The increasing tyrosine content of these myoglobins correlates with a shift in emission maximum to shorter wavelengths with excitation at 280 nm: red kangaroo (Tyr-146) emission maximum 335 nm; horse (Tyr-103, -146) emission maximum 333 nm; sperm whale (Tyr-103, -146, -151) emission maximum 331 nm. Since 280 nm excites both tyrosine and tryptophan, this strongly suggests that tyrosine emission is not completely quenched but also contributes to this fluorescence emission. Upon titration to pH 12.5, there is a reversible shift of the emission maximum to longer wavelengths with an increase greater than 2-fold in fluorescence intensity. With excitation at 305 nm, a tyrosinate-like emission is detected at a pH greater than 12. These studies show that: (1) metmyoglobins, Class B proteins containing both tyrosine and tryptophan residues, exhibit intrinsic fluorescence; (2) tyrosine residues also contribute to the observed steady-state fluorescence emission when excited by light at 280 nm; (3) the ionization of Tyr-146 is likely coupled to protein unfolding.

Animals↗

Biosynthesis of branched-chain fatty acids from branched-chain amino acids in subcutaneous tissue of the marine little toothed whale, Stenella caeruleo-alba.

1. The conversion mechanism for 14CO2 from [14C]Leu, [14C]Ile and [14C]Val and the incorporation of 14C-amino acids into lipids of subcutaneous tissue (melon and blubber), liver and muscle of the adult whale, Stenella caeruleo-alba were studied using a tissue culture method. 2. Iso-acids such as -5:0, -11:0; -13:0 and -15:0 in melon triglycerides were biosynthesized from [14C]Leu. On the other hand, anteiso-acids such as -5:0, -11:0, -13:0, -15:0 and n-11:0 - n-16:0 acids were derived from [14C]Ile. 3. Iso-acids such as -4:0, -12:0, -14:0 and 16:0 were biosynthesized from [14C]Val. 4. Analytical data indicate that the compositions of these acids biosynthesized were similar to that of fatty acids in whale oil. 5. The branched-chain fatty acid biosynthesized in blubber was iso-5:0 acid from [14C]Leu, with no long-chain branched acids, but n-12:0, -14:0 and -16.0 acids were also biosynthesized. 6. Radioactivities derived from 14C-amino acids incorporated into lipids in liver and muscle were extremely low compared with those in subcutaneous tissue. 7. The ratios of 14C-lipids/14CO2 in every 14C-amino acid incorporation were higher in subcutaneous tissue than in liver and muscle, and especially in the case of [14C]Leu, the ratio in melon was quite high. 8. The incorporation of the 14C-amino acids into short- and long-chain acids and alcohols of wax esters was recognized in all experiments.

Adipose Tissue↗

Distribution of dopaminergic fibers and neurons in visual and auditory cortices of the harbor porpoise and pilot whale.

The distribution of putative dopaminergic fibers in two sensory cortical areas in the brain of the harbor porpoise (Phocoena phocoena) and pilot whale (Globicephala melaena) was analyzed at the light and electron microscopic levels using tyrosine hydroxylase (TH) immunohistochemistry. The quantitative analysis of the distribution of labeled fibers demonstrates that the primary visual cortex located in the lateral gyrus and entolateral sulcus contains a denser dopaminergic innervation than the auditory cortex within the posterior portion of the presylvian gyrus. In both areas, TH-immunoreactive fibers are densest in layer I, while layers IIIab and VI have intermediate densities and layers II and IIIc-V have the lowest fiber counts. Layer I is characterized by the presence of very thick TH-immunoreactive fiber populations, in addition to the thin and varicose fiber plexus observed throughout the cortical layers. Electron microscopic analyses demonstrated that some of these thick fibers represent the dendrites of TH-immunoreactive neurons located in the deep portion of layer I. The patterns observed in the present study suggest that the dopaminergic projections to the neocortex in whales have a different organization than in terrestrial mammals, particularly rodents and primates. These differences may reflect the fact that during evolution, the cetacean neocortex has retained many of the cytoarchitectonic features that are usually observed only in proisocortical regions in progressive terrestrial mammals.

Animals↗

Unusually weak oxygen binding, physical properties, partial sequence, autoxidation rate and a potential phosphorylation site of beluga whale (Delphinapterus leucas) myoglobin.

We purified myoglobin from beluga whale (Delphinapterus leucas) muscle (longissimus dorsi) with size exclusion and cation exchange chromatographies. The molecular mass was determined by mass spectrometry (17,081 Da) and the isoelectric pH (9.4) by capillary isoelectric focusing. The near-complete amino acid sequence was determined and a phylogeny indicated that beluga was in the same clad as Dall's and harbor porpoises. There were consensus motifs for a phosphorylation site on the protein surface with the most likely site at serine-117. This motif was common to all cetacean myoglobins examined. Two oxygen-binding studies at 37 degrees C indicated dissociation constants (20.5 and 23.6 microM) 5.7-6.6 times larger than horse myoglobin (3.6 microM). The autoxidation rate of beluga myoglobin at 37 degrees C, pH 7.2 was 0.218+/-0.028 h(-1), 1/3 larger than reported for myoglobin of terrestrial mammals. There was no clear sequence change to explain the difference in oxygen binding or autoxidation although substitutions (N66 and T67) in an invariant rich sequence (HGNTV) distal to the heme may play a role. Structural models based on the protein sequence and constructed on topologies of known templates (horse and sperm whale crystal structures) were not adequate to assess perturbation of the heme pocket.

Amino Acid Sequence↗

Distribution and toxicity of mercury in rats after oral administration of mercury-contaminated whale red meat marketed for human consumption.

Toothed-whales and dolphins have been hunted for human consumption in Japan, and their muscles (red meats) are highly contaminated with mercury (Hg). We investigated the distribution and toxicity of Hg in rats after oral administration of Hg-contaminated whale red meat marketed for human consumption in Japan. Rats were orally administered the red meat homogenate for seven consecutive days (0.5 g red meat/kg-bw/day). The red meat administered to rats contained 81microg/g of total mercury (T-Hg) and 13.4 microg/g of methyl mercury (M-Hg). This dose corresponds to the human consumption of 210 g red meat/60 kg-bw/week, exceeding by about 29 times the provisional tolerable weekly intake of M-Hg at 1.6 microg/kg-bw/week set by JECFA [JECFA, 2003. Joint FAO/WHO expert committee on food additives. 61st meeting, Rome]. Twenty-four hours after the last administration, the distribution of T-Hg in rat organs and biochemical parameters in serum were analyzed. The administration of red meat significantly elevated T-Hg concentrations in the liver, kidney, erythrocytes, cerebral cortex and medulla oblongata from the control levels but did not elevate the T-Hg concentration in serum, showing the typical distribution pattern of M-Hg, not of inorganic Hg. The administration slightly but significantly increased GTP activity and P concentration and decreased BUN concentration in serum, although no abnormalities were observed in rat body weight gain and movement during the 7 days. The occasional consumption of red meat from small cetaceans, therefore, could pose a health problem for not only pregnant women but also for the general population.

Administration, Oral↗

Halogenated organic compounds in archived whale oil: a pre-industrial record.

To provide additional evidence that several halogenated organic compounds (HOCs) found in environmental samples are natural and not industrially produced, we analyzed an archived whale oil sample collected in 1921 from the last voyage of the whaling ship Charles W. Morgan. This sample, which pre-dates large-scale industrial manufacture of HOCs, contained two methoxylated polybrominated diphenyl ethers (MeO-PBDEs), five halogenated methyl bipyrroles (MBPs), one halogenated dimethyl bipyrrole (DMBP), and tentatively one dimethoxylated polybrominated biphenyl (diMeO-PBB). This result indicates, at least in part, a natural source of the latter compounds.

Animals↗

Identification of novel alpha- and gammaherpesviruses from cutaneous and mucosal lesions of dolphins and whales.

Total DNA extracted from mucosal and skin lesions of captive and stranded cetaceans was analyzed for herpesvirus DNA by nested and direct polymerase chain reactions (PCR). The targeted sequences corresponded to a region of the DNA polymerase gene containing multiple conserved amino acid motifs. Herpesvirus genomic DNA fragments (222-244 bp) were amplified from 11 lesions by nested PCR and from eight lesions ( approximately 730 bp) using direct PCR from US cetaceans. Fragments of various sizes were also amplified from skin, spleen and blood of a German dolphin. Sequencing and BLAST analysis of these DNA fragments indicated that alpha- or gammaherpesviruses were present in the cetacean lesions. Alphaherpesviruses were associated with skin lesions of three Atlantic bottlenose dolphins (Tursiops truncatus), while gammaherpesviruses were present in genital lesions of five Atlantic bottlenose dolphins, one Risso's dolphin (Grampus griseus), one dwarf sperm whale (Kogia sima) and one Blainville's beaked whale (Mesoplodon densirostris), as well as in one oral lesion from an Atlantic bottlenose dolphin. Phylogenetic analysis of deduced amino acid sequences showed that the cetacean alphaherpesviruses were most closely related to human alphaherpesviruses, namely, herpes simplex-1 and -2. On the other hand, cetacean gammaherpesviruses were most closely related to Rhadinoviruses. These novel cetacean herpesviruses appeared to be distinct from known herpesviruses of marine and terrestrial vertebrates. The sequencing data strongly suggest that these viruses are most likely cetacean specific and possibly have coevolved with their cetacean hosts.

Amino Acid Sequence↗

Organohalogen and organotin compounds in killer whales mass-stranded in the Shiretoko Peninsula, Hokkaido, Japan.

Blubber and liver samples were obtained for analysis of wide ranges of contaminants from killer whales (Orcinus orca) which were locked away in drifting sea ice on the coast of Rausu, the Shiretoko Peninsula in Eastern Hokkaido, Japan in February 2005. Among the organohalogen compounds analyzed, DDTs were the predominant contaminants with concentrations ranging from 28 to 220 microg/g on a lipid-weight basis followed by PCBs and other organochlorine pesticides. PBDEs levels were two or three orders of magnitude lower than those of PCBs and DDTs. 2,3,7,8-Tetrachlorodibenzo-p-dioxin toxic equivalents (TEQs) derived by WHO mammal-TEF in killer whales were in the range of 110-440 pgTEQ/g. Mono-ortho coplanar PCBs contributed to 75-98% of total TEQs, indicating coplanar PCBs are significant contaminants for risk assessment in this species. The fact that hepatic residue levels of butyltins (from 13 to 770 ng/g wet weight) were much higher than those of phenyltins may be reflecting extensive use of tributyltin as antifouling paint.

Adipose Tissue↗