Cetaceans are fully aquatic predatory mammals that have successfully colonized virtually all marine habitats. Their adaptation to these habitats, so radically different from those of their ...terrestrial ancestors, can give us comparative insights into the evolution of female roles and kinship in mammalian societies. We provide a review of the diversity of such roles across the Cetacea, which are unified by some key and apparently invariable life-history features. Mothers are uniparous, while paternal care is completely absent as far as we currently know. Maternal input is extensive, lasting months to many years. Hence, female reproductive rates are low, every cetacean calf is a significant investment, and offspring care is central to female fitness. Here strategies diverge, especially between toothed and baleen whales, in terms of mother-calf association and related social structures, which range from ephemeral grouping patterns to stable, multi-level, societies in which social groups are strongly organized around female kinship. Some species exhibit social and/or spatial philopatry in both sexes, a rare phenomenon in vertebrates. Communal care can be vital, especially among deep-diving species, and can be supported by female kinship. Female-based sociality, in its diverse forms, is therefore a prevailing feature of cetacean societies. Beyond the key role in offspring survival, it provides the substrate for significant vertical and horizontal cultural transmission, as well as the only definitive non-human examples of menopause. This article is part of the theme issue 'The evolution of female-biased kinship in humans and other mammals'.
Intoxications in Zoo Animals in the Netherlands Wijnands-Kleukers, APG; van Velzen, AG; de Vries, I ...
Clinical toxicology (Philadelphia, Pa.),
06/2008, Letnik:
46, Številka:
5
Journal Article
Recenzirano
Objective: Each year the National Poisons Information Centre (NVIC) receives between 3000 and 3500 questions about intoxications in animals. A small number of these questions concern zoo animals. Our ...aim was to evaluate if there is a particular pattern and if a specific strategy can be developed in order to handle intoxications in zoo animals. Case series: Since 1994, 28 intoxications in zoo animals were reported to the NVIC. These intoxications concerned a great variety of animal species, such as kangaroos, lions, monkeys, and dolphins. In several cases more than one animal was involved. The circumstances of the intoxications were very different and the following intoxicants were suspected to be involved: plants or plant material (18%), pesticides especially herbicides and rodenticides (18%), therapeutics such as anthelmintics (21%), contaminated water or soil (21%), others (18%), unknown (4%). However, in several cases it did not become clear whether the symptoms were the result of an intoxication or may be ascribed to other causes such as infection or stress. Case report: It was suspected that some dolphins had ingested lead from a damaged diving belt because lead particles were found in the drainage system. Furthermore the dolphins suffered from anorexia, leukocytose, liver- and kidney failure, symptoms compatible with a lead intoxication. Therefore it was advised to determine blood lead concentrations. The maximal lead concentration in blood was 95 microgram/dL. Chelation therapy was initiated and after 2 weeks the blood concentration dropped to 16 microgram/dL. Unfortunately this dolphin died 7 days after terminating chelation therapy. It is uncertain whether the concentration has increased again after cessation of chelation therapy, or that 16 microgram/dL is toxic to dolphins, because at autopsy 6 gram lead was found in the stomach and duodenum. Conclusion: Intoxications in zoo animals are rarely reported to the NVIC. The circumstances are very diverse and no particular strategy other then normal clinical toxicological approach can be developed to handle these kinds of intoxications. Most practical is a close interaction between the Poisons Information Centre and the Zoo's veterinarian. Furthermore, the dolphin case illustrates toxic reference values for animals are regularly not available.
Cetaceans are remarkable among mammals for their numerous adaptations to an entirely aquatic existence, yet many aspects of their phylogeny remain unresolved. Here we merged 37 new sequences from the ...nuclear genes
RAG1 and
PRM1 with most published molecular data for the group (45 nuclear loci, transposons, mitochondrial genomes), and generated a supermatrix consisting of 42,335 characters. The great majority of these data have never been combined. Model-based analyses of the supermatrix produced a solid, consistent phylogenetic hypothesis for 87 cetacean species. Bayesian analyses corroborated odontocete (toothed whale) monophyly, stabilized basal odontocete relationships, and completely resolved branching events within Mysticeti (baleen whales) as well as the problematic speciose clade Delphinidae (oceanic dolphins). Only limited conflicts relative to maximum likelihood results were recorded, and discrepancies found in parsimony trees were very weakly supported. We utilized the Bayesian supermatrix tree to estimate divergence dates among lineages using relaxed-clock methods. Divergence estimates revealed rapid branching of basal odontocete lineages near the Eocene–Oligocene boundary, the antiquity of river dolphin lineages, a Late Miocene radiation of balaenopteroid mysticetes, and a recent rapid radiation of Delphinidae beginning ∼10 million years ago. Our comprehensive, time-calibrated tree provides a powerful evolutionary tool for broad-scale comparative studies of Cetacea.
Mammals diversified by colonizing drastically different environments, with each transition yielding numerous molecular changes, including losses of protein function. Though not initially deleterious, ...these losses could subsequently carry deleterious pleiotropic consequences. We have used phylogenetic methods to identify convergent functional losses across independent marine mammal lineages. In one extreme case,
(
) accrued lesions in all marine lineages, while remaining intact in all terrestrial mammals. These lesions coincide with PON1 enzymatic activity loss in marine species' blood plasma. This convergent loss is likely explained by parallel shifts in marine ancestors' lipid metabolism and/or bloodstream oxidative environment affecting PON1's role in fatty acid oxidation. PON1 loss also eliminates marine mammals' main defense against neurotoxicity from specific man-made organophosphorus compounds, implying potential risks in modern environments.
Scotland's tourism trade grosses £2.5 billion annually and supports 180,000 jobs; whale-watching is an important part of this activity. Whales and dolphins are the country's number one wildlife ...attraction
and with 11,770 km of coastline the potential for the Scottish industry is huge. In rural areas it can provide as much as 12% of local income. During the tourist season of 2000, questionnaires and
telephone interviews were used to investigate the sustainability of Scottish whale-watching. 48 operators cooperated providing economic and environmental information. Most operators were found to be local
people (72.4%), supporting five or less full-time equivalent jobs (86.4%). Over half of those questioned (63.2%) had alternative incomes and no formal training in wildlife tourism or
business management (70.8%); 89.5% of respondents stated that they follow a code of conduct. The East Coast and Western Isles show the best-perceived trends in tourist numbers. Whale-watching
in Scotland is shown to have potential for growth but a need to be regulated and managed from within the industry to ensure environmental and economic sustainability into the future.
Marine mammals are susceptible to the effects of anthropogenic contaminants. Here we examine the effect of different polychlorinated biphenyl (PCB) accumulation scenarios on potential population ...growth rates using, as an example, data obtained for the population of bottlenose dolphins from Sarasota Bay, Florida. To achieve this goal, we developed an individual-based model framework that simulates the accumulation of PCBs in the population and modifies first-year calf survival based on maternal blubber PCB levels. In our example the current estimated annual PCB accumulation rate for the Sarasota Bay dolphin population might be depressing the potential population growth rate. However, our predictions are limited both by model naivety and parameter uncertainty. We emphasize the need for more data collection on the relationship between maternal blubber PCB levels and calf survivorship, the annual accumulation of PCBs in the blubber of females, and the transfer of PCBs to the calf through the placenta and during lactation. Such data require continued efforts directed toward long-term studies of known individuals in wild and semiwild populations.
The remarkable fossil record of whales and dolphins (Cetacea) has made them an exemplar of macroevolution. Although their overall adaptive transition from terrestrial to fully aquatic organisms is ...well known, this is not true for the radiation of modern whales. Here, we explore the diversification of extant cetaceans by constructing a robust molecular phylogeny that includes 87 of 89 extant species. The phylogeny and divergence times are derived from nuclear and mitochondrial markers, calibrated with fossils. We find that the toothed whales are monophyletic, suggesting that echolocation evolved only once early in that lineage some 36–34 Ma. The rorqual family (Balaenopteridae) is restored with the exclusion of the gray whale, suggesting that gulp feeding evolved 18–16 Ma. Delphinida, comprising all living dolphins and porpoises other than the Ganges/Indus dolphins, originated about 26 Ma; it contains the taxonomically rich delphinids, which began diversifying less than 11 Ma. We tested 2 hypothesized drivers of the extant cetacean radiation by assessing the tempo of lineage accumulation through time. We find no support for a rapid burst of speciation early in the history of extant whales, contrasting with expectations of an adaptive radiation model. However, we do find support for increased diversification rates during periods of pronounced physical restructuring of the oceans. The results imply that paleogeographic and paleoceanographic changes, such as closure of major seaways, have influenced the dynamics of radiation in extant cetaceans.
Pachycetus paulsonii, Pachycetus wardii, and Antaecetus aithai are middle Eocene archaeocete whales found in Europe, North America, and Africa, respectively. The three are placed in the new ...basilosaurid subfamily Pachycetinae. Antaecetus is a new genus known from Egypt and Morocco, and the only pachycetine known from a substantial postcranial skeleton. The skull of A. aithai described here resembles that of Saghacetus osiris in size, but lacks the narrowly constricted rostrum of Saghacetus. Antaecetus is smaller than Pachycetus and its teeth are more gracile. Upper premolars differ in having two rather than three accessory cusps flanking the principal cusp. Pachycetines differ from dorudontines in having elongated posterior thoracic and lumbar vertebrae like those of Basilosaurus, but differ from basilosaurines and from dorudontines in having conspicuously pachyosteosclerotic vertebrae with dense and thickly laminated cortical bone surrounding a cancellous core. Pachycetinae are also distinctive in having transverse processes on lumbar vertebrae nearly as long anteroposteriorly as the corresponding centrum. We infer from their pachyosteosclerotic vertebrae that pachycetines were probably sirenian-like slow swimmers living in shallow coastal seas and feeding on passing fish and mobile invertebrates.
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