| cetacean mitochondrial dna control region: sequences of all extant baleen whales and two sperm whale species. | the sequence of the mitochondrial control region was determined in all 10 extant species commonly assigned to the suborder mysticeti (baleen or whalebone whales) and to two odontocete (toothed whale) species (the sperm and the pygmy sperm whale). in the mysticetes, both the length and the sequence of the control region were very similar, with differences occurring primarily in the first approximately 160 bp of the 5' end of the l-strand of the region. there were marked differences between the my ... | 1993 | 8412655 |
| an attempt at intracytoplasmic sperm injection of frozen-thawed minke whale (balaenoptera bonaerensis) oocytes. | little is known about the characteristics of fertilisation events in minke whales. cryopreserved minke whale oocytes and spermatozoa do not fertilise in a standard ivf. this study was conducted to investigate the pronucleus formation ability of cryopreserved minke whale oocytes and their subsequent development following intracytoplasmic sperm injection (icsi). in experiment 1, frozen-thawed minke whale immature oocytes were cultured for in vitro maturation (ivm) in a maturation medium (tcm199) s ... | 2001 | 11771896 |
| pathological and serological evidence of brucella-infection in baleen whales (mysticeti) in the western north pacific. | abnormal testes and uterus were observed in 13 males (33%) and one female (3%) out of 40 common minke whales (balaenoptera acutorostrata) in the western north pacific. similar lesions were found in testis and ovary, respectively, in one male (2%) and female (2%) out of 43 bryde's whales (balaenoptera edeni) in the western north pacific. grossly, granular lesions with caseation and calcification were main pathological signs, and they were restricted to reproductive organs of mature whales. chroni ... | 2003 | 12493493 |
| the pattern of ovarian development in the prepubertal antarctic minke whale (balaenoptera bonaerensis). | this study describes the morphological and morphometrical changes associated with prepubertal ovarian development in the antarctic minke whale (balaenoptera bonaerensis). ovaries were harvested from 94 immature minke whales caught in the antarctic ocean during the summer feeding season (december-march). notable differences in ovarian size and morphology were found among animals. up to 10 folds difference in ovarian weight was found among prepubertal whales of similar body size. during the prepub ... | 2004 | 15329469 |
| relationship between the appearance of preantral follicles in the fetal ovary of antarctic minke whales (balaenoptera bonaerensis) and hormone concentrations in the fetal heart, umbilical cord and maternal blood. | the present study aimed to determine the relationship among changes in the number of preantral follicles and concentrations of follicle-stimulating hormone (fsh), luteinizing hormone (lh), progesterone (p4), androstenedione (a) and estradiol-17beta (e2) in the fetal heart, umbilical cord and maternal blood. primordial follicles had already appeared in a 20 cm fetus and primary follicles were observed in a 50 cm fetus. in a 70 cm fetus, the number of primordial and primary follicles increased rap ... | 2004 | 15460107 |
| comparative studies on lipid analysis and ultrastructure in porcine and southern minke whale (balaenoptera bonaerensis) oocytes. | the present study was conducted to clarify the difference in the color of the cytoplasm in immature follicular oocytes from prepubertal and adult minke whales. the four lipid contents (triglyceride, total cholesterol, phospholipids and non-esterified fatty acids) in vitrified immature oocytes from prepubertal and adult minke whales, and also in fresh and vitrified immature porcine oocytes, were measured. the lipid contents in vitrified-warmed minke whale oocytes were similarly high compared with ... | 2004 | 15514458 |
| interspecies somatic cell nuclear transfer for in vitro production of antarctic minke whale (balaenoptera bonaerensis) embryos. | | 2004 | 15671674 |
| attempt at in vitro maturation of minke whale (balaenoptera bonaerensis) oocytes using a portable co2 incubator. | the present study was conducted to investigate whether a portable co2 incubator was effective for in vitro maturation (ivm) of bovine, porcine and minke whale oocytes, and the effect of maturation media supplemented with different hormones; porcine follicle stimulating hormone (pfsh), estradiol-17beta (e2), or pregnant mare's serum gonadotropin (pmsg): human chorionic gonadotropin (hcg) for minke whale immature oocytes was also examined. in vitro maturation rates of bovine and porcine oocytes cu ... | 2005 | 15750298 |
| ecochemical approach using mercury accumulation of antarctic minke whale, balaenoptera bonaerensis, as tracer of historical change of antarctic marine ecosystem during 1980-1999. | | 2006 | 16404672 |
| contribution of spermatozoal centrosomes to the microtubule-organizing centre in antarctic minke whale ( balaenoptera bonaerensis ). | using an interspecies microinsemination assay with bovine oocytes, it was examined whether centrosomes of antarctic minke whale spermatozoa function as the microtubule-organizing centre (mtoc). bull and rat spermatozoa were used as positive and negative controls, respectively. vitrified-warmed bovine mature oocytes were subjected to immunostaining against alpha-tubulin 4-6 h after intracytoplasmic injection (icsi) of 5 mm dithiothreitol-treated spermatozoa. aster formation occurred from whale sp ... | 2006 | 16700975 |
| competition among penguins and cetaceans reveals trophic cascades in the western ross sea, antarctica. | an apparent trophic cascade that appears during summer in the western ross sea, antarctica, explains why the antarctic silverfish (pleuragramma antarcticum) there becomes cannibalistic; its principal prey, crystal krill (euphausia crystallorophias) becomes scarce; and the diatom community is minimally grazed compared to adjacent areas. the krill is the major grazer of diatoms. on the basis of fieldwork at ross island, we suggest that the cascade results from foraging by unusually numerous adélie ... | 2006 | 16937647 |
| aquatic adaptation and the evolution of smell and taste in whales. | while olfaction is one of the most important senses in most terrestrial mammals, it is absent in modern toothed whales (odontoceti, cetacea). furthermore, behavioral evidence suggests that gustation is very limited. in contrast, their aquatic sistergroup, baleen whales (mysticeti) retain small but functional olfactory organs, and nothing is known about their gustation. it is difficult to investigate mysticete chemosensory abilities because experiments in a controlled setting are impossible. | 2015 | 26605054 |
| marine mammal strandings in the new caledonia region, southwest pacific. | four hundred twenty three marine mammals, in 72 stranding events, were recorded between 1877 and 2005 in new caledonia, the loyalty islands, and vanuatu in the southwest pacific. sixteen species were represented in this count, including: minke whale, balaenoptera acutorostrata (1 single stranding), sei whale, b. borealis (1 single stranding), blue whale, b. musculus (1 single stranding), humpback whale, megaptera novaeangliae (2 single strandings), giant sperm whale, physeter macrocephalus (18 s ... | 2006 | 16644500 |
| long-term and large-scale epidemiology of brucella infection in baleen whales and sperm whales in the western north pacific and antarctic oceans. | in a long-term, large-scale serologic study in the western north pacific ocean, anti-brucella antibodies were detected in common minke whales (balaenoptera acutorostrata) in the 1994-2010 offshore surveys (21%, 285/1353) and in the 2006-2010 japanese coastal surveys (20%, 86/436), in bryde's whales (b. edeni brydei) in the 2000-2010 offshore surveys (9%, 49/542), in sei whales (b. borealis) in the 2002-2010 offshore surveys (5%, 40/788) and in sperm whales (physeter macrocephalus) in the 2000-20 ... | 2016 | 27320816 |
| spatial and temporal variation of pcbs and organochlorine pesticides in the antarctic minke whales, balaenoptera bonaerensis, in the period 1987-2005. | concentrations of polychlorinated biphenyls (pcbs), dichlorodiphenyl trichloroethane and its metabolites (ddts), hexachlorocyclohexane isomers (hchs), hexachlorobenzene (hcb) and chlordane compounds (chls) were determined in the blubber of males (20-25 years old) of antarctic minke whales, balaenoptera bonaerensis, from the international whaling commission (iwc) management areas iv (70°-130°e) and v (130°e-170°w), south 60°s. the ranges of concentrations (ng g(-1) lipid wt.) for each compound we ... | 2015 | 25637712 |
| migration of antarctic minke whales to the arctic. | the antarctic minke whale (balaenoptera bonaerensis), and the common minke whale found in the north atlantic (balaenoptera acutorostrata acutorostrata), undertake synchronized seasonal migrations to feeding areas at their respective poles during spring, and to the tropics in the autumn where they overwinter. differences in the timing of seasons between hemispheres prevent these species from mixing. here, based upon analysis of mitochondrial and microsatellite dna profiles, we report the observat ... | 2010 | 21203557 |
| radiation and speciation of pelagic organisms during periods of global warming: the case of the common minke whale, balaenoptera acutorostrata. | how do populations of highly mobile species inhabiting open environments become reproductively isolated and evolve into new species? we test the hypothesis that elevated ocean-surface temperatures can facilitate allopatry among pelagic populations and thus promote speciation. oceanographic modelling has shown that increasing surface temperatures cause localization and reduction of upwelling, leading to fragmentation of feeding areas critical to pelagic species. we test our hypothesis by genetic ... | 2007 | 17391271 |
| review: exploration of placentation from human beings to ocean-living species. | this review covers four topics. 1) placental pathology in himalayan mountain people. to determine morphological changes of the placenta at high altitude, pathological examination was made of 1000 himalayan placentas obtained in nepal and tibet and the results compared with japanese placentas delivered at sea level. characteristic findings in the placental villi of the himalayan group included high incidences of villous chorangiosis and chorangioma. these processes were clarified by ultrastructur ... | 2013 | 23332416 |
| deep-sea whale fall fauna from the atlantic resembles that of the pacific ocean. | whale carcasses create remarkable habitats in the deep-sea by producing concentrated sources of organic matter for a food-deprived biota as well as places of evolutionary novelty and biodiversity. although many of the faunal patterns on whale falls have already been described, the biogeography of these communities is still poorly known especially from basins other than the ne pacific ocean. the present work describes the community composition of the deepest natural whale carcass described to dat ... | 2016 | 26907101 |
| annotated checklist and fisheries interactions of cetaceans in togo, with evidence of antarctic minke whale in the gulf of guinea. | based on strandings and captures, 9 cetacean species, including 6 odontocetes and 3 mysticetes, are documented (photos and specimens) in togo's coastal waters (newly-recorded species marked with an asterisk): antarctic minke whale (balaenoptera bonaerensis*), bryde's whale (balaenoptera brydei or b. edeni), humpback whale (megaptera novaeangliae), sperm whale (physeter macrocephalus), pygmy sperm whale (kogia breviceps*), short-finned pilot whale (globicephala macrorhynchus*), pantropical spotte ... | 2014 | 24447657 |
| the influence of sea ice, wind speed and marine mammals on southern ocean ambient sound. | this paper describes the natural variability of ambient sound in the southern ocean, an acoustically pristine marine mammal habitat. over a 3-year period, two autonomous recorders were moored along the greenwich meridian to collect underwater passive acoustic data. ambient sound levels were strongly affected by the annual variation of the sea-ice cover, which decouples local wind speed and sound levels during austral winter. with increasing sea-ice concentration, area and thickness, sound levels ... | 2017 | 28280544 |
| whole genome resequencing reveals diagnostic markers for investigating global migration and hybridization between minke whale species. | in the marine environment, where there are few absolute physical barriers, contemporary contact between previously isolated species can occur across great distances, and in some cases, may be inter-oceanic. an example of this can be seen in the minke whale species complex. antarctic minke whales are genetically and morphologically distinct from the common minke found in the north atlantic and pacific oceans, and the two species are estimated to have been isolated from each other for 5 million ye ... | 2017 | 28086785 |
| feeding rates and under-ice foraging strategies of the smallest lunge filter feeder, the antarctic minke whale (balaenoptera bonaerensis). | body size and feeding mode are two fundamental characteristics that determine foraging performance and ecological niche. as the smallest obligate lunge filter feeders, minke whales represent an ideal system for studying the physical and energetic limits of filter feeding in endotherms. we used multi-sensor suction cup tags to quantify the feeding performance of antarctic minke whales. foraging dives around and beneath sea ice contained up to 24 lunges per dive, the highest feeding rates for any ... | 2014 | 25122916 |
| cetacean records along a coastal-offshore gradient in the vitória-trindade chain, western south atlantic ocean. | oceanic waters are difficult to assess, and there are many gaps in knowledge regarding cetacean occurrence. to fill some of these gaps, this article provides important cetacean records obtained in the winter of 2010 during a dedicated expedition to collect visual and acoustic information in the vitória-trindade seamounts. we observed 19 groups of cetaceans along a 1300-km search trajectory, with six species being identified: the humpback whale (megaptera novaeangliae, n = 9 groups), the fin whal ... | 2014 | 25055095 |
| mysterious bio-duck sound attributed to the antarctic minke whale (balaenoptera bonaerensis). | for decades, the bio-duck sound has been recorded in the southern ocean, but the animal producing it has remained a mystery. heard mainly during austral winter in the southern ocean, this ubiquitous sound has been recorded in antarctic waters and contemporaneously off the australian west coast. here, we present conclusive evidence that the bio-duck sound is produced by antarctic minke whales (balaenoptera bonaerensis). we analysed data from multi-sensor acoustic recording tags that included inte ... | 2014 | 24759372 |
| counting whales in a challenging, changing environment. | estimating abundance of antarctic minke whales is central to the international whaling commission's conservation and management work and understanding impacts of climate change on polar marine ecosystems. detecting abundance trends is problematic, in part because minke whales are frequently sighted within antarctic sea ice where navigational safety concerns prevent ships from surveying. using icebreaker-supported helicopters, we conducted aerial surveys across a gradient of ice conditions to est ... | 2014 | 24622821 |
| areolae of the placenta in the antarctic minke whale (balaenoptera bonaerensis). | in this study, we examined the existence and structure of areolae and the steroidogenesis of areolar trophoblast cells in the antarctic minke whale placenta morphologically and immunohistochemically. placentas were collected from the 15th, 16th and 18th japanese whale research program under special permit in the antarctic (jarpa) and 1st jarpa ii organized by the institute of cetacean research in tokyo, japan. the opening and cavity of fetal areolae formed by taller columnar trophoblast cells (a ... | 2014 | 24351524 |
| hybrids between common and antarctic minke whales are fertile and can back-cross. | minke whales are separated into two genetically distinct species: the antarctic minke whale found in the southern hemisphere, and the common minke whale which is cosmopolitan. the common minke whale is further divided into three allopatric sub-species found in the north pacific, southern hemisphere, and the north atlantic. here, we aimed to identify the genetic ancestry of a pregnant female minke whale captured in the north atlantic in 2010, and her fetus, using data from the mtdna control regio ... | 2013 | 23586609 |
| structure and steroidogenesis of the placenta in the antarctic minke whale (balaenoptera bonaerensis). | there are few reports describing the structure and function of the whale placenta with the advance of pregnancy. in this study, therefore, the placenta and nonpregnant uterus of the antarctic minke whale were observed morphologically and immunohistochemically. placentas and nonpregnant uteri were collected from the 15th, 16th and 18th japanese whale research programme with special permit in the antarctic (jarpa) and 1st jarpa ii organized by the institute of cetacean research in tokyo, japan. in ... | 2013 | 23269486 |
| stable isotope ratios and mercury levels in red meat products from baleen whales sold in japanese markets. | we analyzed the δ(13)c, δ(15)n and δ(18)o values and hg concentration in red meat products originating from the predominant types sold in japan for human consumption: two populations of common minke (j- and o-types), bryde's and sei whales in the western north pacific ocean, and fin and antarctic minke whales in the southern ocean. the order of the trophic positions, evaluated by δ(15)n values and hg concentrations, coincided with their known feeding habits: common minke (j-type)=common minke (o ... | 2012 | 22364843 |
| are antarctic minke whales unusually abundant because of 20th century whaling? | severe declines in megafauna worldwide illuminate the role of top predators in ecosystem structure. in the antarctic, the krill surplus hypothesis posits that the killing of more than 2 million large whales led to competitive release for smaller krill-eating species like the antarctic minke whale. if true, the current size of the antarctic minke whale population may be unusually high as an indirect result of whaling. here, we estimate the long-term population size of the antarctic minke whale pr ... | 2010 | 20025655 |
| comparing evolutionary patterns and variability in the mitochondrial control region and cytochrome b in three species of baleen whales. | the rapidly evolving mitochondrial control region remains an important source of information on phylogeography and demographic history for cetaceans and other vertebrates, despite great uncertainty in the rate of nucleotide substitution across both nucleotide positions and lineages. patterns of variation in linked markers with slower rates of evolution can potentially be used to calibrate the rate of nucleotide substitution in the control region and to better understand the interplay of evolutio ... | 2009 | 19116685 |
| chemical properties of epidermal lipids, especially sphingolipids, of the antarctic minke whale. | it is well known that sphingolipids specifically exist in the terrestrial mammal epidermis and correlate with skin barrier functions. however, the lipid properties of the marine mammal epidermis have not been examined in detail. we thus investigated the chemical composition of lipid components, especially sphingolipids, in the black epidermis (outer skin) of antarctic minke whales (six mature and six immature specimens). complex lipid fractions mainly contained cerebroside (ce), cholesteryl sulf ... | 2008 | 18188633 |
| follicle size-dependent changes in follicular fluid components and oocyte diameter in antarctic minke whales (balaenoptera bonaerensis). | the concentrations of various components of follicular fluid were compared among three groups of follicles (small, <5 mm; medium: 5-10 mm; large, >10 mm) with a control that consisted of the components of umbilical serum using seven pregnant antarctic minke whales. follicular oocytes recovered from the follicles were also used for measurement of oocyte diameter after removing the cumulus cells. the mean diameter of the ooplasm in the oocytes from the large follicles (143.2 microm) was significan ... | 2007 | 17965544 |
| developmental capacity of antarctic minke whale ( balaenoptera bonaerensis ) vitrified oocytes following in vitro maturation, and parthenogenetic activation or intracytoplasmic sperm injection. | the present study investigated the effects of the sexual maturity of oocyte donors on in vitro maturation (ivm) and the parthenogenetic developmental capacity of fresh minke whale oocytes. the effects of cytochalasin b (cb) pretreatment and two types of cryoprotectant solutions (ethylene glycol (eg) or ethylene glycol and dimethylsulfoxide (eg + dmso)) on the in vitro maturation of vitrified immature whale oocytes were compared, and the developmental capacity of vitrified immature whale oocytes ... | 2006 | 16719944 |
| effects of cryodevice type and donors' sexual maturity on vitrification of minke whale (balaenoptera bonaerensis) oocytes at germinal vesicle stage. | germinal-vesicle-stage oocytes enclosed with compact cumulus cell layers (cocs) were recovered from adult or prepubertal minke whale ovaries, and were vitrified in a solution containing 15% ethylene glycol, 15% dmso and 0.5 m sucrose using either a cryotop or an open-pulled straw (ops) as the cryodevice. the post-warm cocs with normal morphology were cultured for 40 h in a 390 mosmol in vitro maturation medium, and oocytes extruding the first polar body were considered to be matured. the proport ... | 2004 | 15751543 |
| abundance estimation of diving animals by the double-platform line transect method. | in conventional line transect theory, it is assumed that all animals on the line are detected. this article introduces an extended and generalized hazard probability model without the need for such an assumption. the proposed method needs a survey design with independent observers having the same visual region and assumes an explicit distinction of simultaneous and delayed duplicates. it can take account of random heterogeneity caused by surfacing behavior as well as systematic heterogeneity by ... | 2003 | 14601752 |