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The deep oceans of the Southern Hemisphere are home to several elusive and poorly studied marine megafauna. In the absence of robust observational data for these species, genetic data can aid inferences on population connectivity, demography and ecology. A previous investigation of genetic diversity and population structure in Gray's beaked whale ( Mesoplodon grayi ) from Western Australia and New Zealand found high levels of mtDNA diversity, no geographic structure and stable demographic history. To further investigate phylogeographic and demographic patterns across their range, we generated complete mitochondrial and partial nuclear genomes of 16 of the individuals previously analysed and included additional samples from South Africa ( n = 2) and South Australia ( n = 4), greatly expanding the spatial range of genomic data for the species. Gray's beaked whales are highly elusive and rarely observed, and our data represents a unique and geographically broad dataset. We find relatively high levels of diversity in the mitochondrial genome, despite an absence of population structure at the mitochondrial and nuclear level. Demographic analyses suggest these whales existed at stable levels over at least the past 1.1 million years, with an approximately twofold increase in female effective population size approximately 250 thousand years ago, coinciding with a period of increased Southern Ocean productivity, sea surface temperature and a potential expansion of suitable habitat. Our results suggest that Gray's beaked whales are likely to be resilient to near-future ecosystem changes, facilitating their conservation. Our study demonstrates the utility of low-effort shotgun sequencing in providing ecological information on highly elusive species.

Gray's beaked whales (Mesoplodon grayi) are medium-sized odontocete (toothed) cetaceans that are members of the family Ziphiidae. These animals inhabit deep oceanic waters and are rarely seen at sea. Most information is derived from stranded animals and there has been no systematic study of their morphology. We present a multivariate analysis of the morphology of Gray's beaked whales using 80 cranial measurements from 22 individuals and 13 external measurements from 50 individuals. Sparse principal component and linear discriminant function analyses were used to classify samples into sexes. Males and females have markedly different cranial morphology. In particular, females have longer skulls with longer more slender rostra (beaks) in comparison to males. Two variables, depth of the rostrum at mid-length and tip of rostrum to the right temporal fossa, can classify sex with 100% accuracy. The external body measurements used in this study are more prone to error as they were recorded by a number of observers on carcasses in differing states of decomposition and this is reflected in the level of variance in most measurements. However, analyses of these measurements showed a significant difference between sexes in the distance between (1) the tip of the rostrum to the genital slit, (2) the tip of the rostrum to the blowhole, as found in the cranial analyses and (3) tail fluke width where males have absolutely wider tail flukes than females. Differences in these same measurements were also found between animals stranded on the east and west coasts suggesting a degree of population separation across New Zealand. Finally, we present two linear models that enable the assignment of sex from either skull or external measurements. These models will be useful for future studies as well as the management of these whales and can be applied to archived data where genetic sex assignment is not possible.

Some marine mammals are so rarely seen that their life history and social structure remain a mystery. Around New Zealand, Gray's beaked whales (Mesoplodon grayi) are almost never seen alive, yet they are a commonly stranded species. Gray's are unique among the beaked whales in that they frequently strand in groups, providing an opportunity to investigate their social organization. We examined group composition and genetic kinship in 113 Gray's beaked whales with samples collected over a 20-year period. Fifty-six individuals stranded in 19 groups (2 or more individuals), and 57 whales stranded individually. Mitochondrial control region haplotypes and microsatellite genotypes (16 loci) were obtained for 103 whales. We estimated pairwise relatedness between all pairs of individuals and average relatedness within, and between, groups. We identified 6 mother-calf pairs and 2 half-siblings, including 2 whales in different strandings 17 years and 1500 km apart. Surprisingly, none of the adults stranding together were related suggesting that groups are not formed through the retention of kin. These data suggest that both sexes may disperse from their mothers, and groups consisting of unrelated subadults are common. We also found no instances of paternity within the groups. Our results provide the first insights into dispersal, social organization, and the mating system in this rarely sighted species. Why whales strand is still unknown but, in Gray's beaked whales, the dead can tell us much about the living.

We used three second-generation sequencing platforms to develop 12 microsatellite markers for Gray's beaked whale (Mesoplodon grayi). There was a strong correlation between the amount of sequence obtained from each platform and the number of microsatellites recovered. In order to design reliable primers we found that it was important in all cases to eliminate low quality reads and trim sequences so that 80 % of each sequence had a PHRED score of (20. We found that tri- and tetranucleo- tide repeats produced less stutter enabling robust peak- calling and consistent genotyping. The microsatellites developed here will be useful for the population genetics and conservation studies of Gray's beaked whales.

Understanding the genetic structure of a population is essential to its conservation and management. We report the level of genetic diversity and determine the population structure of a cryptic deep ocean cetacean, the Gray's beaked whale (Mesoplodon grayi). We analysed 530 bp of mitochondrial control region and 12 microsatellite loci from 94 individuals stranded around New Zealand and Australia. The samples cover a large area of the species distribution (~6000 km) and were collected over a 22-year period. We show high genetic diversity (h=0.933-0.987, π=0.763-0.996% and Rs=4.22-4.37, He=0.624-0.675), and, in contrast to other cetaceans, we found a complete lack of genetic structure in both maternally and biparentally inherited markers. The oceanic habitats around New Zealand are diverse with extremely deep waters, seamounts and submarine canyons that are suitable for Gray's beaked whales and their prey. We propose that the abundance of this rich habitat has promoted genetic homogeneity in this species. Furthermore, it has been suggested that the lack of beaked whale sightings is the result of their low abundance, but this is in contrast to our estimates of female effective population size based on mitochondrial data. In conclusion, the high diversity and lack of genetic structure can be explained by a historically large population size, in combination with no known exploitation, few apparent behavioural barriers and abundant habitat.

Several species of beaked whales inhabit the Southern Ocean, but information on their abundance, distribution, and seasonality is scarce. However, beaked whales are the only cetaceans known to use frequency modulated (FM) upsweep pulses to echolocate, and these signals appear to be species-specific in their spectral and temporal properties. Accordingly, passive acoustic monitoring has proven useful to investigate the behavioral ecology of these elusive species. Acoustic recordings were collected in Antarctic waters with both a towed hydrophone array as well as a bottom-moored High-frequency Acoustic Recording Package (HARP) deployed near Elephant Island that recorded between March and July 2014. The acoustic data revealed several beaked whale signal types of unknown origin. Of the five species of beaked whales known to occur in the survey area, an acoustic description has only been made for the FM pulses produced by Cuvier?s beaked whales (Ziphius cavirostris). Signal characterization using custom MATLAB-based routines determined that three unidentified FM pulse types are distinctly different from the signal of Cuvier?s beaked whales, and are also unlikely to belong to Arnoux?s beaked whales (Berardius arnuxii). Southern bottlenose whales (Hyperoodon planifrons) likely produce the most dominant beaked whale signal type (BW29) in the towed array and HARP data. The sources of the two less commonly detected echolocation signals, BW37 and BW55, are possibly Gray?s beaked whales (Mesoplodon grayi) and strap-toothed whales (M. layardii). Acoustic encounters over several months indicated differences among the various species in diel and seasonal use of the area near the recorder. Ongoing passive acoustic monitoring in the Southern Ocean will allow us to explore long-term relative abundance and distribution, as well as consistent seasonal and diel patterns, and will provide insight into the ecological role of beaked whales in an ecosystem that is undergoing rapid environmental transitions as a result of climate change. Fil: Trickey, Jennifer S.. University of California at San Diego. Scripps Institution of Oceanography; Estados Unidos Fil: Baumann-Pickering, Simone. University of California at San Diego. Scripps Institution of Oceanography; Estados Unidos Fil: Hildebrand, John. University of California at San Diego. Scripps Institution of Oceanography; Estados Unidos Fil: Reyes Reyes, María Vanesa. Fundación Cethus; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; Argentina Fil: Melcón, Mariana. Fundación Cethus; Argentina Fil: Iñíguez, Miguel. Whale And Dolphin Conservation; Estados Unidos. Fundación Cethus; Argentina

A pair of free-swimming Gray's beaked whales, Mesoplodon grayi, an adult female and a calf, were observed in Mahurangi Harbour, near Warkworth, on the North Island of New Zealand, over 5 consecutive days in June 2001. Beaked whales (family Ziphiidae) are seldom seen at sea due to their oceanic distribution, deep diving ability, elusive behaviour, and possible low abundance. Gray's beaked whale is the most com- mon beaked whale species to strand in New Zealand but observations of live animals in these waters are rare. Colour pattern and behaviour of these little known cetaceans are described. Although both animals appeared to be in good condition, the adult female had a series of deep corrugated scars behind her dorsal fin, likely the result of a ship strike. Other at-sea sightings of this species from International Whaling Commission (IWC)—In- ternational Decade of Cetacean Research (IDCR) minke whale assessment cruises and IWC—Southern Ocean Whale and Ecosystem Research (SOWER) circumpolar cruises are summarised. A cluster of sightings to the south-west of the Chatham Islands may indicate the existence of a "hotspot" for M. grayi in the New Zealand region.

Anisakid nematodes are parasites with an indirect life cycle, involving many hosts, including cetaceans that act as definitive hosts. Identification at species level is crucial for a better understanding of the epidemiology and ecology of these parasites, but an accurate diagnosis based only on morphology is difficult. In Brazil, genetic characterization of anisakids is still rare, with Anisakis typica and A. physeteris being the only two species identified by genetic markers until now. The definitive hosts of A. nascettii are Mesoplodon grayi, M. bowdoini, M. layardii and M. mirus. Geographical locations of A. nascettii include the coasts of New Zealand, South Africa and Europe. In this study, a nematode was collected from a Gervais' beaked whale, Mesoplodon europaeus, stranded in Ceará State, north-east Brazil. Genetic analysis based on 18S rDNA, internal transcribed spacer (ITS) region and mtDNA cox2 gene revealed 100% identity with Anisakis sp. U94365, 99% with Anisakis sp. (MP-2005 EU718477 A. nascettii) and 99% with A. nascettii DQ116431, respectively. Phylogenetic analyses of ITS and cox2 sequences using both neighbour-joining and maximum-likelihood methods provided strong support for a clade with only A. nascettii specimens. This study demonstrated for the first time the identification of A. nascettii in the Brazilian Atlantic Coast, revealing a wider geographical distribution of this parasite worldwide and extending the range of its definitive hosts to a new Mesoplodon species, M. europaeus, the Gervais' beaked whale.

15. Gray’s Beaked Whale Mesoplodon grayi French: Baleine-a-bec de Gray / German: Gray-Zweizahnwal / Spanish: Zifio de Gray Other common names: Scamperdown Whale, Southern Beaked Whale Taxonomy. Mesoplodon gray: Von Haast, 1876, New Zealand, “the Chatham Islands...from specimens stranded...on the Waitangi beach of the main island of that group.” This species is monotypic. Distribution. Ranges from temperate waters of the S Atlantic, Indian, and S Pacific oceans to waters of Antarctica. A single specimen stranded on the Dutch coast is thought to have been a vagrant individual. Descriptive notes. Total length 450-500 cm; weight ¢.900 kg (unconfirmed). Body of Gray's Beaked Whale is spindle-shaped, with greatest girth around its midpoint. Flukes are wide in relation to body length, and tailstock is compressed laterally. Dorsal fin is small and set approximately two-thirds the distance betweentip of the beak and end of the tail. Colorationis typically dark brown, dark gray, or black and paler on the ventral surface. Tip of rostrum is often colored white, especially in adult males. Rostrum and lower jaw form a long distinct beak, and there are two grooves on the throat. Adult males have a single tusk on each side of the lower jaw; tusks are positioned about halfway along the jaw line. Tusks are approximately triangular but may become heavily worn over time. Habitat. Waters greater than 200 m deep. In common with other species of Mesoplodon, Gray's Beaked Whale may be more common in areas of complex seabed topography, but this still has to be confirmed. Food and Feeding. While it is often assumed that Gray's Beaked Whales consume deep-water cephalopods, analyses of stomach contents suggest that they may primarily consume deep-water fish species. In common with other species of beaked whales, Gray's Beaked Whales likely forage at depths greater than 500 m for much of their lives. Breeding. Almost nothing is known about the reproductive biology of Gray’s Beaked Whale. Females give birth to a single offspring after gestation that is likely twelve months. Offspring likely remain dependent on their mothers for at least one year. Activity patterns. There is no information available for this species. Movements, Home range and Social organization. There is no specific information available for this species, but sightings of Gray's Beaked Whales at sea tend to be of relatively small groups of five or fewer individuals. Nothing is known about the typical composition of these groups. Status and Conservation. CITES Appendix II. Classified as Data Deficient on The [UCN Red List. There are no estimates of global population size of Gray's Beaked Whale. It may be one of the more abundant species of Mesoplodon and may be relatively common in some areas, such as waters to the south of New Zealand. Like other species of beaked whales, Gray’s Beaked Whale is potentially affected by ingestion of plastic debris and noise pollution, and individuals can be caught as bycatch in driftnet fisheries. As a species restricted to cooler waters, it may also be vulnerable to effects of climate change. Nevertheless, nothing is known about the form or extent ofthese potential impacts. Bibliography. Macleod, Perrin et al. (2006), MacLeod, Santos & Pierce (2003), Mead (1989b), Rice (1998)., Published as part of Russell A. Mittermeier & Don E. Wilson, 2014, Ziphiidae, pp. 326-357 in Handbook of the Mammals of the World – Volume 4 Sea Mammals, Barcelona :Lynx Edicions on page 355, DOI: 10.5281/zenodo.6608481

Western Australia has an extensive coastline extending 12889 km (excluding islands) from latitude 35 degrees in the south to 14 degrees in the north. The extensive coastline intersects the distribution of many species of beaked whale. A total of 74 Ziphiidae were recorded as stranded along the Western Australian coast between 1940 and 2010 (70 years). Ten of the 21 species of beaked whales currently recognized taxonomically worldwide have been observed in Western Australia with True's beaked whale Mesoplodon mirus and Shepherd's beaked whale Tasmacetus shepherdi recorded more than elsewhere in Australia. Western Australia has the highest species diversity (10) of beaked whale strandings compared to other Australian states and regions. Gray's beaked whale, Mesoplodon grayi, was the most commonly reported species (33 records) and had the largest mass stranding group size (seven) of the beaked whales stranded in Western Australia. The records presented in this paper confirm the distribution of Arnoux's beaked whale Berardius arnuxii, strap-toothed beaked whale Mesoplodon layardii, Shepherd's beaked whale, Blainville's beaked whale Mesoplodon densirostris in Western Australian waters. The records presented of True's beaked whale confirm its presence in Australian waters, with Western Australia a possible key location for this species. Factors causing strandings and death should be investigated in future wherever possible, particularly the rostral injuries reported for six beaked whales. Beaked whale species identification should be confirmed through genetic analysis in future to maximize certainty of species identification.

Using an Illumina platform, we shot-gun sequenced the complete mitochondrial genome of Gray’s beaked whale (Mesoplodon grayi) to an average coverage of 152X. We performed a de novo assembly using SOAPdenovo2 and determined the total mitogenome length to be 16,347 bp. The nucleotide composition was asymmetric (33.3% A, 24.6% C, 12.6% G, 29.5% T) with an overall GC content of 37.2%. The gene organization was similar to that of other cetaceans with 13 protein-coding genes, 2 rRNAs (12S and 16S), 22 predicted tRNAs and 1 control region or D-loop. We found no evidence of heteroplasmy or nuclear copies of mitochondrial DNA in this individual. Beaked whales within the genus Mesoplodon are rarely seen at sea and their basic biology is poorly understood. These data will contribute to resolving the phylogeography and population ecology of this speciose group.

Mesoplodon grayi Von Haast, 1876. Proc. Zool. Soc. Lond., 1876:9. TYPE LOCALITY: New Zealand, "the Chatham Islands... from specimens stranded... on the Waitangi beach of the main island of that group." DISTRIBUTION: Southern Hemisphere: cold-temperate waters; one specimen found in the Netherlands (Boschma, 1950:779). STATUS: CITES - Appendix II. SYNONYMS: australis, haasti. COMMENTS: Reviewed by J. G. Mead (1989c)., Published as part of James G. Mead & Robert L. Brownell, Jr., 1993, Order Cetacea, pp. 349-364 in Mammal Species of the World (2 nd Edition), Washington and London :Smithsonian Institution Press on page 363, DOI: 10.5281/zenodo.7352970

Mesoplodon grayi Von Haast, 1876. Proc. Zool. Soc. Lond., 1876:9. TYPE LOCALITY: New Zealand, Chatham Isl., Waitangi Beach. DISTRIBUTION: Temperate southern oceans, cold temperate waters. COMMENT: One specimen found in the Netherlands; see Boschma, 1950, Proc. K. Ned. Akad. Wet. Ser. B Palaeontol. Geol. Phys. Chem., 53:779 (JGM, DWR). PROTECTED STATUS: CITES - Appendix II as Order Cetacea. ISIS NUMBER: 5301411005004007001., Published as part of James H. Honacki, Kenneth E. Kinman & James W. Koeppl, 1982, Order Cetacea, pp. 290-304 in Mammal Species of the World (1 st Edition), Lawrence, Kansas, USA :Alien Press, Inc. & The Association of Systematics Collections on page 301, DOI: 10.5281/zenodo.7352983, {"references":["Boschma, H. 1950. Maxillary teeth in specimens of Hyperoodon rostratus (Muller) and Mesoplodon grayi von Haast stranded on the Dutch coasts. Koninklijke Nederlandsche Akademie van Wetenschappen, Proceedings, 53 (6): 3 - 14, 4 pls."]}