Convergence of marine megafauna movement patterns in coastal and open oceans.

The extent of increasing anthropogenic impacts on large marine vertebrates partly depends on the animals' movement patterns. Effective conservation requires identification of the key drivers of movement including intrinsic properties and extrinsic constraints associated with the dynamic nature of the environments the animals inhabit. However, the relative importance of intrinsic versus extrinsic factors remains elusive. We analyze a global dataset of ∼2.8 million locations from >2,600 tracked individuals across 50 marine vertebrates evolutionarily separated by millions of years and using different locomotion modes (fly, swim, walk/paddle). Strikingly, movement patterns show a remarkable convergence, being strongly conserved across species and independent of body length and mass, despite these traits ranging over 10 orders of magnitude among the species studied. This represents a fundamental difference between marine and terrestrial vertebrates not previously identified, likely linked to the reduced costs of locomotion in water. Movement patterns were primarily explained by the interaction between species-specific traits and the habitat(s) they move through, resulting in complex movement patterns when moving close to coasts compared with more predictable patterns when moving in open oceans. This distinct difference may be associated with greater complexity within coastal microhabitats, highlighting a critical role of preferred habitat in shaping marine vertebrate global movements. Efforts to develop understanding of the characteristics of vertebrate movement should consider the habitat(s) through which they move to identify how movement patterns will alter with forecasted severe ocean changes, such as reduced Arctic sea ice cover, sea level rise, and declining oxygen content.

Movement responses to environment: fast inference of variation among southern elephant seals with a mixed effects model.

Like many species, movement patterns of southern elephant seals (Mirounga leonina) are being influenced by long-term environmental change. These seals migrate up to 4,000 km from their breeding colonies, foraging for months in a variety of Southern Ocean habitats. Understanding how movement patterns vary with environmental features and how these relationships differ among individuals employing different foraging strategies can provide insight into foraging performance at a population level. We apply new fast-estimation tools to fit mixed effects within a random walk movement model, rapidly inferring among-individual variability in southern elephant seal environment-movement relationships. We found that seals making foraging trips to the sea ice on or near the Antarctic continental shelf consistently reduced speed and directionality (move persistence) with increasing sea-ice coverage but had variable responses to chlorophyll a concentration, whereas seals foraging in the open ocean reduced move persistence in regions where circumpolar deep water shoaled. Given future climate scenarios, open-ocean foragers may encounter more productive habitat but sea-ice foragers may see reduced habitat availability. Our approach is scalable to large telemetry data sets and allows flexible combinations of mixed effects to be evaluated via model selection, thereby illuminating the ecological context of animal movements that underlie habitat usage.

Incorporating non-equilibrium dynamics into demographic history inferences of a migratory marine species.

Understanding how dispersal and gene flow link geographically separated the populations over evolutionary history is challenging, particularly in migratory marine species. In southern right whales (SRWs, Eubalaena australis), patterns of genetic diversity are likely influenced by the glacial climate cycle and recent history of whaling. Here we use a dataset of mitochondrial DNA (mtDNA) sequences (n = 1327) and nuclear markers (17 microsatellite loci, n = 222) from major wintering grounds to investigate circumpolar population structure, historical demography and effective population size. Analyses of nuclear genetic variation identify two population clusters that correspond to the South Atlantic and Indo-Pacific ocean basins that have similar effective breeder estimates. In contrast, all wintering grounds show significant differentiation for mtDNA, but no sex-biased dispersal was detected using the microsatellite genotypes. An approximate Bayesian computation (ABC) approach with microsatellite markers compared the scenarios with gene flow through time, or isolation and secondary contact between ocean basins, while modelling declines in abundance linked to whaling. Secondary-contact scenarios yield the highest posterior probabilities, implying that populations in different ocean basins were largely isolated and came into secondary contact within the last 25,000 years, but the role of whaling in changes in genetic diversity and gene flow over recent generations could not be resolved. We hypothesise that these findings are driven by factors that promote isolation, such as female philopatry, and factors that could promote dispersal, such as oceanographic changes. These findings highlight the application of ABC approaches to infer the connectivity in mobile species with complex population histories and, currently, low levels of differentiation.

The importance of sample size in marine megafauna tagging studies.

Telemetry is a key, widely used tool to understand marine megafauna distribution, habitat use, behavior, and physiology; however, a critical question remains: "How many animals should be tracked to acquire meaningful data sets?" This question has wide-ranging implications including considerations of statistical power, animal ethics, logistics, and cost. While power analyses can inform sample sizes needed for statistical significance, they require some initial data inputs that are often unavailable. To inform the planning of telemetry and biologging studies of marine megafauna where few or no data are available or where resources are limited, we reviewed the types of information that have been obtained in previously published studies using different sample sizes. We considered sample sizes from one to >100 individuals and synthesized empirical findings, detailing the information that can be gathered with increasing sample sizes. We complement this review with simulations, using real data, to show the impact of sample size when trying to address various research questions in movement ecology of marine megafauna. We also highlight the value of collaborative, synthetic studies to enhance sample sizes and broaden the range, scale, and scope of questions that can be answered.

Genetic structure and signatures of selection in grey reef sharks (Carcharhinus amblyrhynchos).

With overfishing reducing the abundance of marine predators in multiple marine ecosystems, knowledge of genetic structure and local adaptation may provide valuable information to assist sustainable management. Despite recent technological advances, most studies on sharks have used small sets of neutral markers to describe their genetic structure. We used 5517 nuclear single-nucleotide polymorphisms (SNPs) and a mitochondrial DNA (mtDNA) gene to characterize patterns of genetic structure and detect signatures of selection in grey reef sharks (Carcharhinus amblyrhynchos). Using samples from Australia, Indonesia and oceanic reefs in the Indian Ocean, we established that large oceanic distances represent barriers to gene flow, whereas genetic differentiation on continental shelves follows an isolation by distance model. In Australia and Indonesia differentiation at nuclear SNPs was weak, with coral reefs acting as stepping stones maintaining connectivity across large distances. Differentiation of mtDNA was stronger, and more pronounced in females, suggesting sex-biased dispersal. Four independent tests identified a set of loci putatively under selection, indicating that grey reef sharks in eastern Australia are likely under different selective pressures to those in western Australia and Indonesia. Genetic distances averaged across all loci were uncorrelated with genetic distances calculated from outlier loci, supporting the conclusion that different processes underpin genetic divergence in these two data sets. This pattern of heterogeneous genomic differentiation, suggestive of local adaptation, has implications for the conservation of grey reef sharks; furthermore, it highlights that marine species showing little genetic differentiation at neutral loci may exhibit patterns of cryptic genetic structure driven by local selection.

Quantification of the maternal-embryonal nutritional relationship of elasmobranchs: case study of wobbegong sharks (genus Orectolobus).

The present study used wobbegong sharks (genus Orectolobus) to assess the threshold value proposed by previous research to categorize strict lecithotrophic from incipient histotrophic species. Totals of 236 and 135 ornate wobbegong Orectolobus ornatus and spotted wobbegong Orectolobus maculatus, respectively, were collected from the New South Wales commercial fishery between June 2003 and May 2006. Eight pregnant gulf wobbegong Orectolobus halei were also recorded outside the sampling period for the first time. The three species were reproductively synchronous with a gestation of c. 10-11 months. Embryos started to be macroscopically visible during January and external yolk sacs were fully absorbed by June to July when embryos were c. 200 mm total length (L(T) ). Internal yolk sacs were first observed during April to May when embryos were c. 160 mm L(T) , reached a peak during June and persisted in embryos immediately prior to parturition. The total wet mass from uterine egg to full-term embryos increased by 44-89% and 45-62%, whereas the total organic mass decreased by 32-33% and 26%, for O. ornatus and O. maculatus, respectively, suggesting that these species are strict lecithotrophic yolk-sac viviparous sharks with no maternal nutrient input. A review of the literature identified various issues and suggested that the previously proposed organic mass loss threshold value separating strict lecithotrophic species from incipient histotrophic species might not be appropriate. Instead, it is recommended that a combination of methods (e.g. estimation of organic mass gain or loss between ovarian egg and developed embryo, histology and electron microscopy of the uterus, radio-tracer assay and uterine fluid analysis throughout gestation) is used to discern between strict lecithotrophic and incipient histotrophic species.

Video playback demonstrates episodic personality in the gloomy octopus.

Coleoid cephalopods, including octopuses, cuttlefish and squid, rely mainly on visual signals when interacting with conspecifics, predators and prey. Presenting visual stimuli, such as models, photographs, mirrors and live conspecifics, can thus provide insight into cephalopod behaviour. These methods, however, have limitations - mirrors and live animals lack experimental control, whereas models and photographs sacrifice motion-based information. Video playback addresses these issues by presenting controlled, moving and realistic stimuli but, to date, video playback has not been used successfully with any cephalopod. Here, we developed a video playback technique for the gloomy octopus (Octopus tetricus) that incorporated recent advances in video technology. We then used this technique to test for personality, which we defined as behavioural differences between individuals that are consistent over time and across ecologically important contexts. We captured wild octopuses and tested them on 3 separate days over a 10 day period. On each test day, subjects were presented with videos of a food item, a novel object and a conspecific. These represented a foraging, novel and threatening context, respectively. A fourth video without a moving stimulus controlled for the playback monitor itself and potential artifacts associated with video playback. Experimental stimuli evoked unambiguous and biologically appropriate responses from the subjects. Furthermore, individuals' responses to the three experimental contexts were highly correlated within a given test day. However, within a given context, individuals behaved inconsistently across the 3 test days. The reordering of ranks suggests that rather than fulfilling the criteria for personality, gloomy octopus show temporal discontinuities, and hence display episodic personality.

Nuclear and mitochondrial DNA reveals isolation of imperilled grey nurse shark populations (Carcharias taurus).

Loss of sharks and other upper-trophic marine predators has sparked worldwide concern for the stability of ocean ecosystems. The grey nurse (ragged-tooth or sand tiger) shark (Carcharias taurus) is Vulnerable on a global scale, Critically Endangered in Australia and presumed extinct in parts of its historical range. We used 193 muscle and fin samples collected from six extant populations to assess global mtDNA and microsatellite diversity and the degree of global population genetic structure. Control region mtDNA diversity was low in every population, and two populations (eastern Australia and Japan) contained only a single mtDNA haplotype. Genetic signatures of recent losses of genetic variation were not yet apparent at microsatellite loci, indicating that this low mtDNA variation is not a result of anthropogenic population declines. Population differentiation was substantial between each population pair except Brazil and South Africa, F(ST) values ranged from 0.050 to 0.699 and 0.100 to 1.00 for microsatellite and mitochondrial data respectively. Bayesian analysis clearly partitioned individuals into five of the populations from which they were sampled. Our data imply a low frequency of immigrant exchange among each of these regions and we suggest that each be recognized as a distinct evolutionary significant unit. In contrast to pelagic species such as whale shark and white shark that may cross ocean basins and where cooperative international efforts are necessary for conservation, grey nurse shark, like many coastal species, need to be managed regionally.

Characterization of the weak SS bonds in the OSSSO and O2SSSO2 molecules.

The weak S1-S3 bonds in the OSSSO trans-disulfoxide and the corresponding sulfone, O(2)SSSO(2), are readdressed at the B3LYP/6-31+G(d) level using both the atoms-in-molecules (AIM) and the electron localization function (ELF) approaches. The S1-S3 bonds are clearly characterized as fractional (i.e., with a bond number or bond order which is less than unity) or protocovalent and are very similar in nature to the weak N-N bond in O(2)NNO(2). These results are in accord with what is obtained by inspection of valence bond structures of the increased-valence type.

The suppression of Antarctic bottom water formation by melting ice shelves in Prydz Bay.

A fourth production region for the globally important Antarctic bottom water has been attributed to dense shelf water formation in the Cape Darnley Polynya, adjoining Prydz Bay in East Antarctica. Here we show new observations from CTD-instrumented elephant seals in 2011-2013 that provide the first complete assessment of dense shelf water formation in Prydz Bay. After a complex evolution involving opposing contributions from three polynyas (positive) and two ice shelves (negative), dense shelf water (salinity 34.65-34.7) is exported through Prydz Channel. This provides a distinct, relatively fresh contribution to Cape Darnley bottom water. Elsewhere, dense water formation is hindered by the freshwater input from the Amery and West Ice Shelves into the Prydz Bay Gyre. This study highlights the susceptibility of Antarctic bottom water to increased freshwater input from the enhanced melting of ice shelves, and ultimately the potential collapse of Antarctic bottom water formation in a warming climate.

Cultural traditions across a migratory network shape the genetic structure of southern right whales around Australia and New Zealand.

Fidelity to migratory destinations is an important driver of connectivity in marine and avian species. Here we assess the role of maternally directed learning of migratory habitats, or migratory culture, on the population structure of the endangered Australian and New Zealand southern right whale. Using DNA profiles, comprising mitochondrial DNA (mtDNA) haplotypes (500 bp), microsatellite genotypes (17 loci) and sex from 128 individually-identified whales, we find significant differentiation among winter calving grounds based on both mtDNA haplotype (FST = 0.048, ΦST = 0.109, p < 0.01) and microsatellite allele frequencies (FST = 0.008, p < 0.01), consistent with long-term fidelity to calving areas. However, most genetic comparisons of calving grounds and migratory corridors were not significant, supporting the idea that whales from different calving grounds mix in migratory corridors. Furthermore, we find a significant relationship between δ(13)C stable isotope profiles of 66 Australian southern right whales, a proxy for feeding ground location, and both mtDNA haplotypes and kinship inferred from microsatellite-based estimators of relatedness. This indicates migratory culture may influence genetic structure on feeding grounds. This fidelity to migratory destinations is likely to influence population recovery, as long-term estimates of historical abundance derived from estimates of genetic diversity indicate the South Pacific calving grounds remain at <10% of pre-whaling abundance.

The usefulness of DSM-III axis IV and axis V assessments.

DSM-III multiaxial diagnoses were given to 257 patients. Analysis of axis I diagnoses and axis IV and axis V assessments generally revealed the expected associations between particular psychiatric disorders and levels of psychosocial stress and social and occupational functioning. However, a major difficulty affecting the usefulness of axis IV and axis V data when they are routinely gathered according to the current DSM-III instructions is the stipulation that the clinician judge the etiological significance of a stressor before it is coded.

Strategic allocation of ejaculates by male Adélie penguins.

Sperm competition theory suggests that males should strategically allocate sperm to those females that will bring them the best possible genetic returns. Although males of a number of species of insects and fishes have been shown to allocate sperm strategically, we provide, to our knowledge, the first evidence that an avian species is also capable of allocating ejaculates. Male Adélie penguins (Pygoscelis adeliae) are more likely to transfer sperm during extra-pair copulations (EPCs) than during pair copulations. We investigated the question of how males allocate ejaculates within the constraints of limited sperm availability and found (i) that males that engaged in EPC attempts ejaculated less often when copulating with their social partner than males that made no EPC attempts, and (ii) that there was no difference between males that were involved in failed EPC attempts and those that were involved in successful EPCs in the proportion of copulations that resulted in sperm transfer. These results indicate that males achieve strategic allocation of sperm within the constraints of limited sperm availability by withholding ejaculates from their social partners.

Alliance membership and kinship in wild male bottlenose dolphins (Tursiops aduncus) of southeastern Australia.

Bottlenose dolphins are one of only a few mammalian taxa where the males are known to cooperate within their social group in order to maintain mating access to single females against other males. Male bonds in bottlenose dolphins have been hypothesized as evolving through kinship and associated inclusive fitness effects. In this study we tested whether individually identified male bottlenose dolphins preferentially associate and form alliances with kin in a small coastal resident population of southeastern Australia using a combination of behavioural data, genetic sexing, sequences of the mitochondrial DNA control region and nuclear microsatellite markers. Males generally associated significantly more often than expected with one to three other males, with whom they jointly herded females for mating. Associations and alliance membership were not associated with either maternal kinship or genetic relatedness. The majority of male pairs within alliances were randomly related, although high relatedness values were found between males of different alliances in the resident population. These findings indicate that mechanisms other than kin selection may be foremost in the development and maintenance of cooperation between male bottlenose dolphins.

Identification of a juvenile hormone esterase gene by matching its peptide mass fingerprint with a sequence from the Drosophila genome project.

Juvenile hormone esterase (JHE, EC 3.1.1.1) from whole Drosophila melanogaster prepupae has previously been purified by selective precipitations, isoelectric focussing and two column chromatography steps. JHE bands from dried silver-stained SDS-PAGE gels of that material were digested with trypsin. The masses of the tryptic digest peptides were determined by MALDI-TOF mass spectrometry. Only one predicted gene product (CG8425) from the D. melanogaster genome matches the JHE tryptic fingerprint with high confidence. This predicted JHE sequence includes features that are conserved among all active members of the serine carboxylesterase multigene family as well as features peculiar to JHEs from other species. Also we show that this JHE can be purified by an alternative method using anion exchange chromotography followed by trifluoromethylketone affinity chromatography. A cDNA encoding this JHE was isolated using 3' and 5' RACE. This sequence is in agreement with the Drosophila genome project's prediction except that the sixth predicted intron is not removed; instead there is a stop codon followed by a polyadenylation signal and a polyA tail.

An evaluation of the safety of cefuroxime axetil during six months oral administration to beagle dogs.

The effects of repeated oral administration of cefuroxime axetil were assessed in Beagles. The test material, an ester, is hydrolysed following absorption from the intestine to yield the therapeutically active moiety, cefuroxime, together with acetic acid and acetaldehyde; in this study cefuroxime and unhydrolyzed cefuroxime axetil were detected in the blood. Cefuroxime axetil was administered twice daily during 27 weeks by gavage of aqueous, suspensions, total daily doses were equivalent to 100, 400 or 1600 mg cefuroxime/kg/day. Apart from three cases of intercurrent illness, unrelated to treatment, the dogs remained in good health. Effects observed in the 1600 mg/kg group included vomiting and slight suppression of body weight gain. Minor variations in haematological measurements included rather low haemoglobin levels, packed cell volumes and erythrocyte counts. Slightly smaller numbers of neutrophils were thought to reflect reduced demand on normal defensive mechanisms due to continued antibiotic treatment. Prolongation of prothrombin time and activated partial thromboplastin time is attributed to disturbance of the intestinal microbial flora and reduced synthesis of vitamin K, on which the dog is highly dependent. Cefuroxime does not have the N-methylthiotetrazole side chain thought to be responsible for inhibition by other cephalosporins of the vitamin K-dependent step in the synthesis of clotting factors. Variations in plasma chemistry included rather low levels of plasma protein. Electrophoresis showed this to be a generalised reduction; only gamma globulins were proportionally decreased and this finding, like the low neutrophil counts, is attributed to the protective action of the antibiotic. Minor metabolic adjustments to the compound are reflected in plasma levels of cholesterol and triglycerides. This spectrum of findings was seen only to a very limited extent in the 400 mg/kg group; the 100 mg/kg group was, with very few exceptions, unaffected by the treatment. Macroscopic post mortem examination and microscopic examination of tissues revealed no treatment-related features indicative of toxicity. Cefuroxime axetil was thus shown to possess very little toxicity when administered repeatedly in large doses to Beagles. The lowest dose level in this study was ten times the proposed daily clinical dose in man.

Risk factors associated with bruising in red deer at a commercial slaughter plant.

Bruising of slaughter animals has both economic and welfare implications. In order to identify potential risk factors we surveyed bruising of red deer carcasses from a single Deer Slaughter Plant (DSP) over a three year period. Downgrading due to bruising did not vary between the three years surveyed [1991, n = 21 454, 6.5% downgraded (dg); 1992, n = 22 289, 7.9% dg; 1993, n = 22 262, 6.1% dg]. From an intensive examination of one year's kill (1991) we related the incidence of bruising to various preslaughter transport, seasonal and animal variables. Bruising varied significantly with time of year, hot carcass weight, distance transported, carrier company and carcass fatness. Bruising was related to duration of lairage for some periods of the year which varied with sex. The majority of bruising was on one or other hindquarter implying a consistent cause of the damage. Carcass quality and deer welfare can be best protected by careful driving, by only transporting animals in good condition and avoiding transporting males during the rut.

Polyarteritis in a colony of beagles.

The clinical and pathological features of polyarteritis occurring in a colony of beagles are described. Meningeal and cardiac arteries were most commonly involved. Amyloidosis and lymphocytic thyroiditis were also present in some of the affected dogs. The polyarteritis is probably of autoimmune origin.