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Understanding the effect of stage-specific traits on species feeding habits can reveal how natural selection shapes life strategies. Amino acid (AA) nitrogen stable isotopes (δ15 N) provide multiple proxies of habitat baseline values and diet that can improve our understanding of species feeding strategies relative to their animal metabolism. We evaluated the effect of body length as a proxy for life stage and sex on the feeding habits of the common dolphin Delphinus delphis delphis using δ13 C and δ15 N in bulk tissue and AAs δ15 N from skin samples collected for almost two decades. For bulk δ13 C and δ15 N data, we used SIBER analysis to compare isotopic niches by sex and life stage. For AA δ15 N data, we developed a hierarchical Bayesian model (HBM) to estimate indices of trophic status (Δ15 N and trophic position). The model reflected the natural hierarchical structure of AA data by partitioning variability into three sources: between laboratory replicates, within dolphins and among dolphins. Estimates of Δ15 N based on all trophic and source AAs were more precise for each dolphin, less variable among dolphins and on average 2.4‰ higher than indices based on single trophic (Glx) and source (Phe) AAs. Precision was further increased when information was shared among individuals through random effects or regression models. Estimates of trophic position showed similar patterns. Both Δ15 N and δ15 Nbulk isotopic niches showed no difference by sex, suggesting that males and females have similar feeding habits and may not segregate. However, lower Δ15 N values for weaning calves and smaller juveniles discriminate them from adults, whereas δ15 N bulk isotopic niches do not. A trophic discrimination factor (TDFTro-Src ) of 3.1‰ was required for reasonable estimates of trophic position for these dolphins. Together, the lack of δ15 N differences between sexes, low variation between juveniles and adults and knowledge of common dolphins' social organization support intraspecific feeding cooperation as an important strategy to feed in the highly dynamic marine environment. Our study also presents an efficient way to analyse complex AA δ15 N data using HBM to investigate foraging behaviour in long-lived marine species difficult to study in the wild.

Dolphins’ whistles are strongly diversified mainly related to physiology and behaviour. We present the whistle characteristics and intraspecific variations of short-beaked common dolphins Delphinus...

The common dolphins (genus Delphinus) are widely distributed in all temperate and tropical oceans. Over this wide geographical distribution they show considerable range in morphological variation, which has led to descriptions of several species in the genus. Until recently, only two species of Delphinus were accepted, but this classification has become contentious. This study investigated the occurrence of morphologically different types of Delphinus in South African waters and assessed geographic and morphometric variations within each type. A total of 296 skulls of Delphinus spp., obtained from the Port Elizabeth Museum and the Iziko South African Museum, were photographed in their dorsal and ventral aspects for geometric morphometric analysis. Our results revealed three clusters of specimens based on analysis of the dorsal aspect of the skull, and two clusters for the ventral aspect. Significant differences in cranial size were found between clusters. Both cranial aspects showed that the main variations in skull shape occurred in the rostral region and braincase area, indicating divergent adaptations relating to these features. There was a substantial difference between the composition of the dorsal-aspect and ventralaspect clusters, suggesting the presence of only one species in South African waters. Significant differences between morphological clusters associated with the three regions within the study area (cold-temperate, warm-temperate and subtropical) are probably mediated through differences in local environmental conditions (e.g. different water temperatures and productivity).Keywords: cranial morphology, Delphinus delphis, geographical variation, geometric morphometrics, rostral index, sexual dimorphism, taxonomy

Aim In the marine environment, where there are few physical boundaries to gene flow, there is often nevertheless intraspecific diversity with consequences for effective conservation and management. Here, we compare two closely related dolphin species with a shared distribution in the Indian Ocean (IO) to better understand the biogeographic drivers of their population structure. Location Global oceans and seas with a focus on the Indian Ocean Taxon Tursiops sp. and Delphinus sp. Methods Bayesian, ordination, assignment, statistical and phylogenetic analyses to assess phylogeography, connectivity and population structure using microsatellite and mitochondrial DNA genetic markers. Results Both Tursiops sp. and Delphinus sp. showed population structure across the western IO and, in each case, populations in the Arabian Sea (off India, Pakistan and Oman) were most differentiated. Comparisons with other populations worldwide revealed independent lineages in this geographic region for both genera. For T. aduncus, (for which multiple sites within the IO could be compared), Bayesian modelling best supported a scenario of expansion southwards following a bottleneck event resulting in differentiation between the northern and western IO. For Delphinus, the same pattern is even more pronounced. Populations in the Arabian Sea region of the north-western IO show genetic isolation for each of the two genera, consistent with other studies of cetacean species in this region. Main conclusions We propose that changes in the intensity of the southwest monsoon during the climate cycles of the Pleistocene could have affected regional patterns of productivity and represent an important biogeographic driver promoting the observed patterns of differentiation and population dynamics seen in our focal species. Patterns of population genetic structure are consistent with phenotypic differences, suggesting an influence from distinct habitats and resources, and emphasising the need for effective conservation measures in this geographic region.

Understanding how animals use the space in which they are distributed is important for guiding management decisions in conservation, especially where human disturbance can be spatially managed. Here we applied distribution modelling to examine common dolphin (Delphinus sp.) habitat use in the Hauraki Gulf (36°S, 175°E), New Zealand. Given the known importance of the area for foraging and nursing, we assessed which variables affect Delphinus occurrence based on generalised additive models (GAMs), and modelled probability of encounter. Behavioural information was included to assess habitat use by feeding and nursing groups and determine whether persistent hotspots for such activities could be identified and meaningfully used as a spatial management tool. Using data collected from dedicated boat surveys during 2010–2012, depth and sea surface temperature (SST) were frequently identified as important variables. Overall, seasonal predictive occurrence maps for the larger population resembled predictive maps of feeding groups more than nursery groups, suggesting prey availability has important implications for the distribution of Delphinus in this region. In this case, static spatial exclusions would not be the best management option as the core areas of use identified for these activities were large and shifted temporally. It appears that at the scale examined, most of the Hauraki Gulf is important for feeding and nursing rather than specific smaller regions being used for these functions. In cases where static management is not the optimal tool, as suggested here for a highly mobile species, a dynamic approach requires more than a boundary line on a map.

Autumn brings with it the transition from hot, sultry nights to cool, crisp evenings. ‘Seeing’ conditions generally improve during this season. Good seeing conditions will be needed if you are to locate the rather faint constellations of autumn. Several of the constellations are found in an area of the sky called “The Water” because of the number of water-related constellations. Delphinus (the Dolphin), Pisces (the Fishes), Aquarius (the Water-Bearer), Cetus (the Sea-Monster), Capricornus (the Sea-Goat), and Pisces Austrinus (the Southern Fish) are all found in this area of the sky. Although there is no lack of constellations the number of bright stars is decidedly lacking, as are the number of deep sky objects. These constellations are formed by 3rd to 5th magnitude stars so a dark, Moonless night and a star chart will help a lot when navigating the sky. Some wonderful stories accompany these constellations.

This paper deals with a neglected subgenre of biblical poetry, namely with epic poems on the life of the Blessed Virgin. After an introduction into the poetic treatment of Mary in early modern latin poetry in general, one single epic poem is discussed in detail, the Mariados libri tres of the Italian-German scholar Giulio Cesare Delfini. As it will be demonstrated, Delfini’s poem included long explanations of medico-theological problems, like the digestion of the Divine Virgin or her intellectual skills, which the poet treated in addition in separate glosses. As result the poem presents itself as hybrid between didactic and epic poetry. In addition the study contains as an Appendix a list of (approximately) all accessible Latin poems, written between 1550 and 1650, on the incarnation and birth of Christ.

Vanenga Schaus, 1928, like many other Mimallonidae genera being revised in recent years, has not been studied since Schaus (1928) in his revision of the family. This currently monotypic genus is entirely restricted to South America, with no known representatives in Central or North America. Prior to this work, Schaus (1928) and subsequent lists of the family (Gaede 1931, Becker 1996) have mentioned the single species Vanenga mera (Dognin, 1924) described from the Brazilian Amazon (Pará state). In Schaus (1928) this species is listed as occurring in both Amazonia and southeastern Brazil. In completing the present article, numerous “type” specimens have been discovered bearing three different manuscript names associated with the populations of southeastern Brazil and adjacent areas. Despite the fact that these names were written on various labels, the absence of any published descriptions results in them being unavailable (ICZN 1999). Therefore, this distinct southern South American species is now officially recognized and formally described, as well as providing a much more thorough distribution for both Vanenga species, including many new records for Vanenga mera.

Bilateral nephrolithiasis with a concurrent vaginal calculus was identified in a stranded free-ranging long-beaked common dolphin Delphinus capensis. Necropsy and radiologic examinations of the sexually mature D. capensis revealed multiple small irregularly round nephroliths and a 6.4 × 4.1 × 9.2 cm vaginal calculus weighing 182 g. Nephroliths numbered 68 and 71 in the left and right kidneys, respectively, and ranged from 1.7 to 6.9 mm in diameter. Nephroliths were composed of 100% ammonium urate, which has been found in captive dolphin populations. However, the vaginolith consisted of struvite and calcium carbonate suggesting an alternate etiology. The composition of the vaginolith suggests that bacterial vaginitis could have served as the predisposing condition. Renal lesions included chronic tubulointerstitial nephritis with tubular degeneration and loss, likely secondary to the nephroliths. The pathogenesis of ammonium urate nephrolithiasis in managed care is suspected to be linked to diet and age but in this case may be due to metabolic disruption. However, if environmental changes cause a shift in prey species, the risk of nephrolithiasis in free-ranging cetaceans could increase. Careful surveillance for nephroliths in free-ranging populations should be considered by researchers.

Odontocetes are constantly on the move, but resulting movement patterns have rarely been analyzed comparatively. Within the continuum of space and time, several distinct patterns appear: diel, short-term, seasonal, and exceptionally long-distance movements, together delineating home ranges that may be occupied for extended periods or repeatedly. A variety of methods have been used to study movement patterns of odontocetes, such as absence/presence, photo-identification of individuals, static acoustic monitoring, and marking and tagging of individuals (e.g., with radio tags or satellite transmitters). These methods can provide a wealth of information at a variety of scales and thus not always comparable. We highlight examples of recent research on selected taxa: Physeter, Ziphiidae and Globicephalinae, Orcinus, Monodontidae, Stenella, Grampus, Delphinus, Tursiops, Sousa, Sotalia, Cephalorhynchus, Phocoena, Neophocaena, Phocoenoides, Inia, and Platanista. Prey availability and predation pressure are main drivers of movement patterns, although social factors also shape movement patterns, to date much overlooked.

Phylogenetic relationships in the family Delphinidae have been widely debated. We examined 347 skulls of Tursiops, Stenella, Delphinus, Steno, Lagenodelphis, and Sousa in order to resolve the phylogenetic position of Australian species of Tursiops. Five Tursiops type specimens were included. Cranial morphology was described using 2-dimensional (2-D) and 3-dimensional geometric morphometrics (3-GM), counts and categorical data. Analyses showed a clear morphological separation of Tursiops, including type specimens, from other genera. The three Stenella species did not cluster together. Stenella attenuata clustered with Delphinus delphis, and Stenella coeruleoalba with Lagenodelphis hosei. Length and width of the skull and rostrum were important discriminators in both methods. For 3-D data, round vs. angular posterior skull shape distinguished some genera. Taxa that overlapped in the multivariate analyses had different mean tooth counts. Our study challenges genetic studies that identified Tursiops as polyphyletic, with T. aduncus closer to S. attenuata.

Understanding species distributions, and how they change in space and time, is vital when prioritising conservation or management initiatives. We assessed the distribution and density patterns of common dolphins (Delphinus sp.), bottlenose dolphins (Tursiops truncatus) and Bryde’s whales (Balaenoptera edeni) in the Hauraki Gulf, New Zealand. Dedicated boat-based surveys were conducted in the inner Hauraki Gulf (IHG) and off Great Barrier Island (GBI) during 2010–2012. Generalised linear models were used to investigate temporal changes in relative densities and kernel density estimation was implemented to examine spatial trends. Common dolphins were widely distributed during all seasons, with higher densities observed during winter and spring in the IHG but during autumn off GBI. There was inter-annual variation in Bryde’s whale distribution, with high densities recorded off GBI in 2011. Bottlenose dolphins were infrequently sighted in the IHG but regularly encountered off GBI, with the highest den...

Dolphins are widespread in warm oceanic and coastal waters. They habitually frequent islands. In California, Chile, and other localities, prehistoric peoples targeted dolphins. Some communities specialised in their capture. Elsewhere, prehistoric human use of cetaceans is attributed to opportunistic exploitation of active or stranded animals. In Meso- and Central America, the scarcity of cetaceans in archaeological sites is inferred to reflect the difficulties of their capture at sea with available technology. An unrecorded regional pattern is evident on Pedro Gonzalez Island in the Pearl Islands (Panama). Remains of bottlenose and common dolphins were found in a Preceramic midden (“Playa Don Bernardo” [PDB]) located in a reef- and mangrove-fringed bay. Eight 14 C-dates bracket the deposit between 6200 and 5600 calibrated years BP. The Preceramic strata, which are between 0.8 m and nearly 4 m deep, are capped by a pottery-bearing soil deposited after a 3000-yr. hiatus in occupation. Delphinid bones and teeth represent 8% of 3660 mammal specimens identified to Family in three small test cuts. These cuts represent only 0.7% of the estimated midden area. A minimum of fourteen dolphin individuals is inferred: 11 belong to common dolphin ( Delphinus ), two to bottlenose dolphin ( Tursiops ), and one, possibly, to harbour dolphin (cf Stenella ). Several bones show evidence for cuts, scrapes and thermal alteration. Some modifications are anthropogenic. Dry season upwelling induces shoaling fish to enter bays in the Pearl Islands attracting their nektonic, avian and dolphin predators. Ecologically, Don Bernardo Bay suits the short-beaked common dolphin ( Delphinus delphis ) and the common bottlenose nose dolphin ( Tursiops tuncatus ) — the most likely species to be present on the basis of osteology and zoogeography. The opportunistic use of naturally beached dolphins is one hypothesis for their procurement at PDB. Another is intentional human interference: corralling and driving dolphins with watercraft when they entered Don Bernardo Bay to feed or under threat from shark attacks. Ethnographic evidence around the world is supportive. PDB's total subsistence strategy was multi-faceted, comprising exploiting dolphins and marine turtles, farming, marine shore collecting, marine coastal fishing, and hunting in island forests and secondary vegetation. The population included experienced seafarers. Among the exploited mammals, dolphins provided easily the largest quantities of edible tissues, fats and oils.

We have sequenced the female and male mtDNA of Unio delphinus and inferred the Unionidae phylogeny using 41 complete mtDNA sequences. Additionally, we compared the concatenated mtDNA trees with those using single or combination of two mtDNA genes to identify the best genes to use in the absence of complete mitogenomes. The gender-specific mtDNAs of U. delphinus contain all Unionida mtDNA specific features. The mtDNA phylogeny supports the reciprocal monophyly of the gender-specific clades but it was inconclusive regarding Unionidae subfamilies relationships. The gene trees topologies using ND5 or 16S-rRNA with ND1 were the closest trees to the mtDNA trees.

The short-beaked common dolphin (Delphinus delphis delphis) (SBCD) is an odontocete inhabiting the Gulf of California (GC), Mexico; distributed widely in temperate to tropical waters, it is sometimes observed close to shore or in shallower areas. On 13 February 2018, a mass stranding of 54 SBCDs occurred in La Paz Bay in the southern GC; 21 individuals died, but the rest were released. Skin samples were removed from dead individuals for stable isotope analysis in order to infer their probable geographical provenance. Their mean ± S.D. were 17.0 ± 0.3‰ ( δ 15 N) and -18.3 ± 0.2 ( δ 13 C), with no significant differences between sexes or length. These isotope ratios do not correspond to the GC. Their low δ 13 C and δ 15 N values reflect offshore foraging grounds not under the 15N-enriching effects of the intense denitrification in the GC. Rather, these values were within the range of other piscivorous odontocetes that have been sampled in the GC and classified as outsiders (Pacific Ocean). Mean total length of these stranded SBCDs was similar to that reported for SBCDs off the Pacific coast of Baja California and southern California, but widely smaller than that reported for both eastern tropical Pacific SBCDs and long-beaked common dolphins (Delphinus delphis bairdii) in the northern and southern GC. These differences in isotopic niche and size between SBCDs stranded in La Paz Bay and long-beaked common dolphins from other regions of the GC highlight the need to be able to distinguish between the common dolphins (Delphinus) that inhabit the GC from those that visit the GC from off the Pacific coast of Baja California. Our findings confirm the ecological importance of the southern GC, where resident and visitor marine mammals congregate, leading to events like mass strandings that provide a unique source of information useful for research and conservation.

Genus Delphinus Linnaeus, 1758 Delphinus was regarded as a monospecific genus with a single species, D. delphis, until two species were recognized based on both morphology and mtDNA analysis (Heyning & Perrin 1994; Nowak 2003); both occur in Korean waters., Published as part of Jo, Yeong-Seok, Baccus, John T. & Koprowski, John L., 2018, Mammals of Korea: a review of their taxonomy, distribution and conservation status, pp. 1-216 in Zootaxa 4522 (1) on page 151, DOI: 10.11646/zootaxa.4522.1.1, http://zenodo.org/record/2610198, {"references":["Linnaeus, C. (1758) Systema naturae per regna tria naturae: secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Fol. 1. 10 th Edition. Laurentii Salvii, Stockholm, 824 pp. [in Latin]","Heyning, J. E. & Perrin, W. F. (1994) Evidence for two species of common dolphins (Genus Delphinus) from the eastern North Pacific. Contributions in Science, 442, 1 - 35","Nowak, R. M. (2003) Walker's Marine Mammals of the World. Johns Hopkins University Press, Baltimore, 264 pp."]}

Delphinus capensis Gray, 1828 —Long-beaked Common Dolphin Delphinus capensis Gray, 1828 p.2; Type locality- Cape of Good Hope, South Africa; Kuroda, 1938 p.15; Kim et al., 2000 p.96; Kim, 2004 p.242. D. bairdii Dall, 1873 p.12; Type locality- Coast of California, US. Range: Delphinus capensis is readily observed along the east coast of Korea during spring and autumn with the peak of occurrence in spring; this dolphin rarely occurs along the coast of Korea in winter (Fig. 103). Remarks: All common dolphins were classified in a single species, D. delphis, until 1994. Heyning and Perrin (1994), later confirmed by Kingston and Rosel (2004), recognized two distinct species: the long-beaked common dolphin (D. capensis) and the short-beaked common dolphin (D. delphis). The taxonomic status of D. capensis has been further clarified in a morphometric study (Jefferson & Van Waerebeek 2002). Delphinus capensis may be difficult to distinguish from D. delphis, especially at sea. The slender body and longer beak contrast with the shortbeaked common dolphin. The beak has a sharp demarcation from the somewhat flattened melon. The slightly muted coloration and a chin-to-flipper stripe, which often merges with the lip patch, thus darkening the lower jaw, is broader (Jefferson et al. 2008). Since D. delphis is very rare in Korean waters (Amano 2009a, b), previous records of D. delphis in Korea were mostly D. capensis. The Subspecies, D. c. capensis Gray, 1828, occupies the waters of Korea., Published as part of Jo, Yeong-Seok, Baccus, John T. & Koprowski, John L., 2018, Mammals of Korea: a review of their taxonomy, distribution and conservation status, pp. 1-216 in Zootaxa 4522 (1) on pages 153-154, DOI: 10.11646/zootaxa.4522.1.1, http://zenodo.org/record/2610198, {"references":["Gray, J. E. (1828) Spicilegia Zoologica; or Original Figures and Short Systematic Descriptions of New and Unfigured Animals. Fol. 1. Treuttel, Wurtz and Co., London, 30 pp.","Kuroda, N. (1938) A list of the Japanese Mammals. Published by Author, Tokyo, 122 pp.","Kim, Z. G., Lee, J. U., Baik, C. I., Sohn, H. S., Park, C. S., Lee, D. W., Choi, K. H., Hong, B. Q., Kim, S. T., Park, J. H., Cho, Y. M., Cha, H. K. & Hwang, K. S. (2000) Whales and Dolphins off Korean Peninsula. National Fisheries Research & Development Institute, Busan, 137 pp. [in Korean]","Kim, Z. G. (2004) Suborder Pinnipedia & Order Cetacea. In: Won, B. O. (Ed.), The mammals of Korea. Dongbang Media Press, Seoul, pp. 184 - 254. [in Korean]","Dall, W. H. (1873) description of three new species of Cetacea, from the coast of Califonia. Proceedings of the California Academy of Science, 5, 12 - 14.","Heyning, J. E. & Perrin, W. F. (1994) Evidence for two species of common dolphins (Genus Delphinus) from the eastern North Pacific. Contributions in Science, 442, 1 - 35","Kingston, S. E. & Rosel, P. E. (2004) Genetic differentiation among recently diverged delphinid taxa determined using AFLP markers. The Journal of Heredity, 95, 1 - 10. https: // doi. org / 10.1093 / jhered / esh 010","Jefferson, T. A. & Van Waerebeek, K. (2002) The taxonomic status of the nominal dolphin species Delphinus tropicalis van Bree, 1971. Marine Mammal Science, 18, 787 - 818. https: // doi. org / 10.1111 / j. 1748 - 7692.2002. tb 01074. x","Jefferson, T. A., Webber, M. A. & Pitman, R. L. (2008) Marine mammals of the world. Elsevier, Amsterdam, 592 pp.","Amano, M. (2009 a) Delphinus capensis Gray, 1928. In: Ohdachi, S. D., Ishibashi, Y., Iwasa, M. A. & Saitoh, T. (Eds.), The Wild Mammals of Japan. Shoukadoh, Kyoto, pp. 356 - 357."]}

A case of intergeneric hybridization in the wild between a female bottlenose dolphin (Tursiops truncatus) and a short-beaked common dolphin (Delphinus delphis), considered members of 'vulnerable' and 'endangered' subpopulations in the Mediterranean, respectively, by the International Union of Conservation of Nature is described in this paper. The birth of the hybrid was registered in the Bay of Algeciras (southern Spain) in August 2016, and the animal has been tracked on frequent trips aboard dolphin-watching platforms. This unique occurrence is the result of an apparent ongoing interaction (10 years) between a female bottlenose dolphin and common dolphins. The calf has a robust body with length similar to Tursiops, while its lateral striping and coloration are typical of Delphinus. It displays the common dolphin's 'criss-cross' pattern. However, the thoracic patch is lighter than in D. delphis and its dorsal area is light grey, with a 'V' shape under the dorsal fin. This paper also provides a comprehensive mini-review of hybridizations of T. truncatus with other species.

Publisher Summary The stocky dusky dolphin from the Southern Hemisphere and the Pacific whitesided dolphin, Lagenorhynchus obliquidens , from the northern Pacific Ocean are considered phylogenetically closely related species despite the absence of a fossil record. Some researchers suggested that L. obliquidens could almost equally well be regarded as a subspecies of the dusky dolphin. The smallish dusky dolphin can be recognized by its short beak and the bluish black to dark gray of the dorsal field contrasting with the white belly, as well as the light gray of the thoracic patch and two-pronged flank patch. The dark lips and eye patch also stand out. The falcate dorsal fin is two-toned with a dark leading edge. Unlike in L. obliquidens , the linear dorsal flank blaze does not extend farther anteriorly than about mid-body. Heavily pigmented specimens are found off Peru and Argentina. The holotype of Delphinus fitzroy caught off Argentina from Darwin's ship, Beagle, was such a melanistic form. Various cases of anomalous, piebald pigmentation are probably equivalent to so-called partial albinism.

Rationale Distinguishing population units of small cetaceans continuously distributed in a widespread area is challenging but critical for their conservation and management. The use of chemical markers allows the investigation of foraging ecology and inter-specific variability, in order to detect population structure and niche segregation in the common dolphin (Delphinus spp.). Methods The stable isotope ratios of carbon (δ13C values) and nitrogen (δ15N values) were measured in the bone tissue of common dolphins accidentally by-caught or stranded along the north-eastern and eastern Subtropical Atlantic Ocean, by means of continuous flow elemental analyser/isotope ratio mass spectrometry. Trophic positions were determined and compared, taking into account the local ecosystem trophic baseline for each study area. Data obtained for the study areas were qualitatively compared with those for common dolphin species/populations distributed worldwide. Results The δ13C and δ15N values were higher in the eastern Subtropical Atlantic as a consequence of the coexistence in the area of the common dolphin short- and long-beaked morphotypes. Individuals from the north-eastern Atlantic displayed lower δ15N values, reflecting dissimilarities in diet and variation in local isotopic baselines. Comparisons with other areas around the world suggest that the species is extremely adaptive and feeds at different trophic levels to adapt to local variations. Conclusions Stable isotopes are a useful tool to investigate population structure and trophic niche segregation. The trophic behaviour of worldwide populations of common dolphins was fruitfully analysed and revealed substantial differences, probably reflective of both adaptive strategies of the genus and dissimilarities in the structure of the ecosystems. Copyright © 2015 John Wiley & Sons, Ltd.

This study proposes a simple standardized method for the production of analog X-ray images of dolphin teeth, and to explore its potential use as a complementary technique in the evaluation of dental pathology in small cetaceans. We investigated exposure times that produced the best results, and whether radiographs helped in the diagnosis of macroscopic abnormalities. Teeth of six species of dolphins (Delphinidae: Tursiops truncatus, Steno bredanensis, Sotalia guianensis, Delphinus sp., Stenella coeruleoalba, and Stenella frontalis) were X-rayed in an analog dental X-ray machine operating at 70 kVp and 7 mA. Intraoral size 2 standard films were used, and the focus-film distance was standardised at 35 cm. Those species with smaller teeth (total length 12-20 mm) had the best results when exposed for 0.3 seconds, while species with larger teeth (30-45 mm) had to be exposed for 0.4 seconds for their best result. Three independent examiners analysed all the images taken. The average pairwise percent agreement was 73% (Fleiss' Kappa = 0.229), suggesting fair agreement between examiners. Analog X-ray images produced were useful in complementing the diagnosis of dental pathology and abnormalities in dolphins, in addition to allowing the observation of internal details and lesion depths, which would not be possible with conventional macroscopic methods. The use of analog X-ray imaging is easily applicable to the study of dolphin teeth, with low operating costs and simple logistics compared to other non-destructive analytical approaches such as Micro-CT.

Blubber progesterone levels were measured in biopsy samples and used to predict the pregnancy status of 507 female common dolphins (204 long-beaked common dolphins, Delphinus capensis, and 303 short-beaked common dolphins, D. delphis). Samples were collected in the coastal waters of the eastern North Pacific between central California, USA and the southern end of Baja California, Mexico. The percentage of females pregnant was similar between the two species: 22.1% (n = 45) of D. capensis and 28.1% (n = 85) of D. delphis. For both species we found strong geographic patterns in pregnancy, suggesting that some areas were more conducive for pregnant females. A sizable drop in percent pregnant from early (38.8%, n = 133) to late (25.3%, n = 91) autumn was found in D. delphis but not in D. capensis. The potential for sample selectivity was examined via biopsies collected either from a large research ship or from a small, rigid-hull inflatable boat (RHIB) launched from the larger ship. An analys...

Helicobacter infection in cetaceans was first reported from the US in 2000 when the isolation of a novel Helicobacter species was described from two Atlantic white-sided dolphins (Lagenorhynchus acutus). Since then, Helicobacter species have been demonstrated in cetaceans and pinnipeds from around the world. Since 1990, the Animal Health and Veterinary Laboratories Agency Polwhele, Truro, has been involved in the UK Cetacean Strandings Investigation Programme to establish the cause of death of cetacean species stranded along the coast of Cornwall, England. We describe the isolation of Helicobacter cetorum in a striped dolphin (Stenella coeruleoalba) and evidence of H. cetorum infection in cetaceans from European waters.

We conducted a meta-analysis of the publication statistics for Vols. 1-8 of the Latin American Journal of Aquatic Mammals ( LAJAM ), the joint scholarly publication of the Sociedad Latinoamericana de Especialistas en Mamiferos Acuaticos and the Sociedad Mexicana de Mastozoologia Marina , with the following purposes: (a) identifying the main patterns in the authorship and content published between 2002 and 2010, and (b) assessing the contributions of these scientific societies in the Latin American and global contexts. With the caveat that the results are only representative of the researchers that chose to publish in LAJAM during the period covered by the study, the metadata from 168 articles indicated that most of the research was conducted on small odontocetes ( Sotalia , Pontoporia , Tursiops ) and pinnipeds ( Arctocephalus, Otaria, Mirounga ) of coastal habits. Rorqual whales ( Balaenoptera , Megaptera ) and oceanic odontocetes ( Stenella, Mesoplodon, Orcinus, Delphinus ) also were well represented. Studies of distribution (including first records) were the most common, followed by those related to feeding, strandings, health and bycatch. Seventeen countries were represented in the primary affiliation of the lead author, but just five dominated the contribution: Brazil (52%), Argentina (10%), Mexico (7%), Uruguay (5%) and USA (5%). Among institution types, a university was reported as the primary affiliation type by 50% of the authors, while 26% reported a NGO, 17% a government agency and 7% another type of organization. A social network analysis of 404 authors identified a large, well-connected cluster of 263 authors. Within this cluster, 13 authors from Brazil, Peru, Argentina and Colombia were among the most collaborative. The female to male ratio was 1:1.6 among lead authors and 1:3.2 among lead authors that published more than one article, suggesting a gender disparity within this scientific community. According to Google Scholar ™, 91 articles in LAJAM were cited in other publications through January 2012, with an average of 7.5 citations per article. The 15 most cited articles had between 13 and 15 citations, were predominantly from Brazil, and were mainly about small cetaceans.

Our count of living species remains incomplete. In the 250-plus years since Carl Linnaeus set up the modern taxonomic system, we have classified about 1.25 million species, about three-quarters of them animals. Another 17 percent are plants, and the remainder are fungi and microbes. And that's the official count — the still-unrecognized number of species could be several times higher still. • The diversity of man-made objects is easily as rich. Although my comparisons involve not just those proverbial apples and oranges but apples and automobiles, they still reveal what we have wrought. • I begin constructing my parallel taxonomy with the domain of all man-made objects. This domain is equivalent to the Eukarya, all organisms having nuclei in their cells. It contains the kingdom of complex, multicomponent designs, equivalent to Animalia. Within that kingdom we have the phylum of designs powered by electricity, equivalent to the Chordata, creatures with a dorsal nerve cord. Within that phylum is a major class of portable designs, equivalent to Mammalia. Within that class is the order of communications artifacts, equivalent to Cetacea, the class of whales, dolphins, and porpoises, and it contains the family of phones, equivalent to Delphinidae, the oceanic dolphins. • Families contain genera, such as Delphinus (common dolphin), Orcinus (orcas), and Tursiops (bottlenose dolphins) in the ocean. And, according to GSM Arena, which monitors the industry, in early 2019 there were more than 110 mobile-phone genera (brands). Some genera contain a single specific species — for instance, Orcinus contains only Orcinusorca, the killer whale. Other genera are species-rich. In the mobile-phone realm none is richer than Samsung, which now includes nearly 1,200 devices. It is followed by LG, with more than 600, and Motorola and Nokia, each with nearly 500 designs. Altogether, in early 2019 there were some 9,500 different mobile “species”—and that total is considerably larger than the known diversity of mammals (fewer than 5,500 species).

The current paucity of published blood values and other clinically relevant data for short-beaked common dolphins, Delphinus delphis, hinders the ability of veterinarians and responders to make well-informed diagnoses and disposition decisions regarding live strandings of this species. This study examined hematologic, clinical chemistry, and physical parameters from 26 stranded common dolphins on Cape Cod, Massachusetts, in light of their postrelease survival data to evaluate each parameter's efficacy as a prognostic indicator. Statistically and clinically significant differences were found between failed and survived dolphins, including lower hematocrit, hemoglobin, TCO2, and bicarbonate and higher blood urea nitrogen, uric acid, and length-to-girth ratios in animals that failed. In general when compared to survivors, failed dolphins exhibited acidosis, dehydration, lower PCVs, and decreased body condition. Additionally, failed dolphins had the highest ALT, AST, CK, LDH, GGT, and lactate values. These blood values combined with necropsy findings indicate that there are likely a variety of factors affecting postrelease survival, including both preexisting illness and stranding-induced conditions such as capture myopathy. Closer evaluation of these parameters for stranded common dolphins on point of care analyzers in the field may allow stranding personnel to make better disposition decisions in the future.

Dolphins are known to produce nearly omnidirectional whistles that can propagate several kilometers, allowing these sounds to be localized and tracked using acoustic arrays. During the fall of 2007, a km-scale array of four autonomous acoustic recorders was deployed offshore of southern California in a known dolphin habitat at ~800 m depth. Concurrently with the one-month recording, a fixed-point marine mammal visual survey was conducted from a moored research platform in the center of the array, providing daytime species and behavior visual confirmation. The recordings showed three main types of dolphin acoustic activity during distinct times: primarily whistling during daytime, whistling and clicking during early night, and primarily clicking during late night. Tracks from periods of daytime whistling typically were tightly grouped and traveled at a moderate rate. In one example with visual observations, traveling common dolphins (Delphinus sp.) were tracked for about 10 km with an average speed of ~2.5 m s(-1) (9 km h(-1)). Early night recordings had whistle localizations with wider spatial distribution and slower travel speed than daytime recordings, presumably associated with foraging behavior. Localization and tracking of dolphins over long periods has the potential to provide insight into their ecology, behavior, and potential response to stimuli.

Population parameters of poorly marked gregarious species are difficult to estimate. This is the case for common dolphins (Delphinus sp.), a genus known for its lack of distinctive marks resulting in a low mark ratio. Furthermore, the widespread nature of common dolphins results in low recaptures. We developed reliable photo-identification protocols to ensure accurate identification of individuals in the Hauraki Gulf, New Zealand. These protocols combined the use of nicks and notches and pigmentation patterns for identification and included the development of a distinctiveness threshold. The data were further stratified by the level of distinctiveness of each individual (as distinctive or highly-distinctive). Photo-identification surveys were conducted from January 2010 to December 2013. Mark-recapture techniques were implemented through a POPAN super-population approach to estimate seasonal apparent survival, capture probability and abundance of dolphins. A total of 2,083 unique adult common dolphins were identified, 51.3% were classified as D1 (highly distinctive; n = 1,069) and 48.7% as D2 (distinctive; n = 1,014). Of all individuals identified, 34.3% (n = 704) were re-sighted over subsequent years. The proportion of marked dolphins (when compared to unmarked dolphins) was 26.3% for D1 and 46.4% for D1 & D2, respectively. Apparent survival was estimated at 0.767 (CI = 0.694–0.827) for D1 animals, and 0.796 (CI = 0.729–0.850) for D1 & D2 combined. For D1 only, seasonal abundance varied from 732 (CI = 460–1,177) in autumn 2010 to 5,304 (CI = 4,745–5,930) in spring 2013. While the inclusion of D2 individuals may offer a more precise estimate of total abundance, the inability to determine additional sources of bias (for example, arising from under or overestimated mark ratios) meant that estimates for D1 individuals were deemed the least biased for this population. The photo-identification protocol, stratification of the data and steps taken to eliminate potential model violations provided a useful and novel approach to estimate population parameters for common dolphins. These approaches could be implemented for other large gregarious populations (≥500 individuals) of animals with poor natural markings.

The health, postrelease movements, and behavior of mass stranded Atlantic white-sided dolphins (Lagenorhynchus acutus) and short-beaked common dolphins (Delphinus delphis) from Cape Cod, Massachusetts, were evaluated. Health was assessed through physical examination and blood analysis. Eleven dolphins (eight white-sided dolphins and three common dolphins) were relocated, outfitted with satellite transmitters, and released during seven mass stranding events. Five transmitters recorded only location, and six also included a time-depth recorder. Transmission duration ranged from 8 h to 218 d, with a mean of 117 d (median = 118 d, SD = 82 d), after release. All dolphins demonstrated extensive movement throughout the Gulf of Maine. The distribution of tagged dolphins was considered normal based on comparisons with published data for these species. Excluding the dolphin that transmitted for only 8 h, mean minimum speeds for individual dolphins ranged from 3.4 to 6.6 km/h; overall mean for all dolphins was 5.4 km/h (SD = 0.9 km/h). The five dolphins with time-depth recorders had mean dive depths of 8.6–40.3 m and mean dive durations of 46–296 s. Hematologic and biochemical data revealed only minor abnormalities. Data suggest that at least 10 of the 11 dolphins were likely successfully reintroduced into the wild.

The history of the taxonomy and classification of the Famennian genus Praeglyphioceras Wedekind, 1908 and the family Praeglyphioceratidae are discussed. The sutural ontogeny of this genus, which is examined for the first time for two species of the genus, supports the high taxonomic rank of praeglyphioceratids. This family is mostly related to primitive Prionoceratoidea. A new species, Praeglyphioceras korobkovi sp. nov., is described from the delphinus Zone (Prolobites-Platyclymenia Genozone) of the Aktyubinsk Region of Kazakhstan.

Quantifying the vocal repertoire of a species is critical for subsequent analysis of signal functionality, geographic variation and social relevance. Vocalisations of free-ranging common dolphins (Delphinus sp) have not previously been described from New Zealand waters. Herein, I present the first quantitative analysis of whistle characteristics to be undertaken on the New Zealand population. Acoustic data were collected in the Hauraki Gulf, Auckland between February 2008 and May 2009, during surveys from the tour boat Dolphin Explorer. Data were collected from 28 independent dolphin groups using PZ-1A hydrophone and MZ-NH700 digital audio disk. Recordings were analysed using Raven Pro 1.3 and whistles classified into seven contours containing 29 subtypes. A total of 105.1 minutes of recordings were collected involving 11,715 whistles. Vocalisations of New Zealand common dolphins spanned 3.2 to 23.00 kHz, with most whistles occurring between 11 and 13 kHz. The shortest and longest whistles recorded were 0.01 and 4.00 s (mean = 0.27, SD = 0.32), respectively. Of the twelve whistle types recorded, 82% have previously been recorded within U.K populations. Additional contours, apparently specific to New Zealand Delphinus were also identified. Of the 2,663 whistles analysed, downsweeps (35.9%) were the most frequent whistle type, followed by upsweeps (28.5%), constant (16.4%) and sine (7.0%) contours. Concave and convex contours were least observed within the New Zealand population, accounting for just 6.1% each. Of all the whistle types identified in Hauraki Gulf common dolphins, the least modulated subtypes were the most prevalent. Data presented here offer a first insight into the whistle characteristics of New Zealand common dolphins. Comparsions with previously studied populations reveal marked differences in the whistle frequency and modulation of the New Zealand population. Inter-population differences suggest behaviour and the local environment likely play a role in shaping the vocal repertoire of this species.

Correlations between surface behavior and concurrent underwater vocalizations were modeled for common dolphins (Delphinus spp.) in the Southern California Bight (SCB) over multiple field seasons. Clicks, pulsed calls, and whistles were examined, with a total of 50 call features identified. Call features were used to classify behavior using random forest decision trees, with rates of correct classification reaching 80.6% for fast travel, 84.6% for moderate travel, 59.8% for slow travel, and 58% for foraging behavior. Common dolphins spent most of their time traveling. The highest number of clicks, pulsed calls, and complex whistles were produced during fast travel. In contrast, during foraging there were few pulsed calls and whistles produced, and the whistles were simple with narrow bandwidths and few harmonics. Behavior and vocalization patterns suggest nocturnal foraging in offshore waters as the primary feeding strategy. Group size and spacing were strongly correlated with behavior and rates of calling, with higher call rates in dispersed traveling groups and lower call rates in loosely aggregated foraging groups. These results demonstrate that surface behavior can be classified using vocalization data, which builds the framework for behavioral studies of common dolphins using passive acoustic monitoring techniques.

We detail the first direct, at sea monitoring of small cetacean interactions with Peruvian artisanal drift gillnet and longline fisheries. A total of 253 small cetaceans were captured during 66 monitored fishing trips (Gillnet: 46 trips; Longline: 20 trips) from the port of Salaverry, northern Peru (8 o 14 0 S, 78 o 59 0 W) from March 2005 to July 2007. The most commonly captured species were common dolphins (Delphinus spp.) (47%), dusky dolphins (Lagenorhynchus obscurus) (29%), common bottlenose dolphins (Tursiops truncatus) (13%) and Burmeister’s porpoises (Phocoena spinipinnis) (6%). An estimated 95% of common dolphin bycatch was of long-beaked common dolphins (Delphinus capensis). Overall bycatch per unit effort for gillnet vessels (mean ± sd) was estimated to be 0.65 ± 0.41 animals.set � 1 (range 0.05–1.50)

The north-eastern coast of Venezuela hosts a high diversity of megafauna, particularly related with high productivity due to coastal upwelling. This area is mainly characterized by the existence of the primary fisheries in Venezuela, mostly supported by a great abundance of small pelagic species. This would explain why the area supports a wide range of marine top predators, including cetaceans. The current status of cetacean populations off north-eastern Venezuela is uncertain, mainly because research efforts have been very sparse. There are still many gaps of information in cetacean biology to establish a solid baseline that can be used for management decisions. Common dolphins (Delphinusspp.) are widely dispersed over the whole north-east basin, including waters off Araya and Paria Peninsula and around Margarita, Coche and Cubagua Islands. Areas of higher densities forDelphinusspp. coincide with the focal location of sardine fisheries and the most-active upwelling on the north-eastern coast. Therefore, a scheme of management should consider the areas of major productivity along the coast as potential critical habitat for the species. Further data collection is recommended, increasing aspects such as trophic ecology and the continuity of behavioural sampling, paired with systematic line transect estimation.

Here we present the first data describing the behavior of common dolphins (Delphinus sp.) in the Hauraki Gulf, New Zealand. Activity budgets are used to assess the effects of diel, season, depth, sea surface temperature, group size, and composition on dolphin behavior. Additionally, the presence/absence of Bryde's whale (Balaenoptera brydei) and Australasian gannet (Morus serrator) is examined in relation to dolphin behavior. Behavioral data were collected from 686 independent dolphin groups during boat-based surveys conducted between February 2002 and January 2005. Foraging (46.7%) and social (7.2%) were the most and least frequently observed behaviors, respectively. Travel (28.9%), mill (9.5%), and rest (7.7%) accounted for the remainder of the activity budget. Behavior varied seasonally, with the highest proportion of foraging and resting groups observed during the spring and autumn, respectively. Behavior also varied with water depth, with foraging animals observed in the deepest and resting groups recorded in the shallowest regions of the Hauraki Gulf. A correlation between group size and behavior was evident, although behavior did not vary with the composition of dolphin groups. Resting, milling, and socializing animals were more frequently observed in smaller group sizes. Foraging behavior was prevalent in both small and large group sizes, suggesting foraging plasticity exists within this population. Behavior differed between single- and multispecies groups, with foraging more frequent in multispecies groups. Resting, milling, or socializing was rarely observed in the presence of any associated species, indicating the primary mechanism for association is likely prey related.

Due to indications that misidentification (largely confusion among dolphins of the genera Delphinus and Stenella) in the past had led to erroneous assumptions of distribution of the two species of common dolphins (Delphinus delphis and D. capensis) in the western Atlantic Ocean, we conducted a critical re-examination of records of the genus Delphinus from this region. We compiled 460 ‘plottable’ records, required support for confirmation of genus and species identifications, and found many records lacking (and some clearly misidentified). When we plotted only the valid records (n = 364), we found evidence of populations in only three areas, and apparent absence throughout much of the tropical/subtropical regions. Off the east coast of the US and Canada, D. delphis is found from the Georgia/South Carolina border (32°N) north to about 47–50°N off Newfoundland. Since the 1960s, they have apparently been absent from Florida waters. There is no evidence that dolphins of the genus occur in the Gulf of Mexico. Reports of common dolphins from most of the Caribbean Basin are also rejected, and the only place in that region where they are confirmed to occur is off central-eastern Venezuela (a coastal D. capensis population). Off eastern South America, common dolphins appear to be restricted to south of 20°S. There is a coastal long-beaked population found in the South Brazil Bight, and one or more short-beaked populations south and offshore of this (ranging south to at least northern Argentina). The results are very different from commonly-accepted patterns of distribution for the genus in the Atlantic. Most areas of distribution coincide with moderate to strong upwelling and common dolphins appear to avoid warm, tropical waters. This study shows that great care must be taken in identification of similar-appearing long-beaked delphinids, and that uncritical acceptance of records at face value can lead to incorrect assumptions about the ranges of the species involved.

The common dolphin (Delphinus sp.) is the most frequently observed cetacean species in the Hauraki Gulf, a large shallow body of water on the northeastern coastline of North Island, New Zealand. Herein, we present the first data relating to the occurrence and distribution of common dolphins in this region and assess the possible effects of abiotic parameters on the demographics of this population. The presence of associated marine species is quantified, and differences in the occurrence and demographics of single and multi-species groups are examined. Sightings data were collected between February 2002 and January 2005 during boat-based surveys. We recorded 719 independent encounters with common dolphins, involving 1 to > 300 animals. Dolphin presence was significantly affected by month, latitude and depth. Group size varied significantly by month, season, depth, sea surface temperature (SST) and latitude, and was highly skewed towards smaller groups made up of < 50 animals. Larger aggregations were most frequent during the austral winter when nutrient upwelling typically leads to increased prey availability within the region. Over 70% of groups encountered contained immature animals and 25% of groups included neonates. Calves were observed throughout the year but were most prevalent in the austral summer months of December and January. Month, season, depth, and SST significantly affected group composition. Common dolphins were observed in association with four cetacean and eight avian species, most frequently with the Australasian gannet (Morus serrator) and the Bryde’s whale (Balaenoptera brydei). The distribution of dolphin-only groups differed significantly from that of dolphin-whale groups, with mono-specific groups found on average in waters that were 3.6 m shallower and 3.1oC warmer. The year-round occurrence and social organisation of common dolphins in Hauraki Gulf waters suggest this region is important both as a calving and nursery ground.

Common dolphins Delphinus sp. are frequently targeted by tourism operations in New Zealand waters, yet there is a paucity of data on potential impacts faced by this species. Transition matrix models, used widely in population ecology, have recently been applied to behavioural transitions in order to provide successful management guidelines. We detail the use of Markov chain models to assess the impact of tourism activities on the behavioural state of common dolphins in the Hauraki Gulf, New Zealand. First-order time discrete Markov chain models were used to describe transition probabilities in both control and impact scenarios. The effect of boat interactions was quantified by comparing transition probabilities of both control and impact chains. Foraging and rest- ing bouts were significantly disrupted by boat interactions to a level that raises concern about the sustainability of this impact. Both the duration of bouts and the overall time spent in these 2 be- havioural states decreased. Foraging dolphins took significantly longer to return to their initial behavioural state in the presence of the tour boat. There was also an increased preference to shift behaviour to socialising or milling after tour boat interactions. Impacts identified in the present study are similar to those previously reported for bottlenose dolphins, a coastal species typically considered to be more susceptible to cumulative anthropogenic impacts.

We examined the skulls of 72 bottlenose dolphins from the Indian and western Pacific Oceans to clarify the systematics in genusTursiops. We also examined type skulls ofTursiops aduncus (Ehrenberg, 1832),T. eurynome (Gray, 1846),T. catalania (Gray, 1862),Delphinus (Steno) gadamu Owen 1866,T. dawsoni Lydekker 1908, andT. truncatus (Montagu, 1821). The specimens were divided into two groups, A and B, based on rostrum length and characters of the basal part of the rostrum. The rostrum of group A was longer and tapered abruptly near the base, whereas that of group B was shorter and tapered more gradually throughout its length. Group A contained specimens from western, central, and eastern Asia, Africa, and Australasia. Group B contained specimens from central and eastern Asia and Australasia. The six type skulls were also clearly divided into two groups; the type skulls ofT. aduncus, T. catalania, andDelphinus (Steno) gadamu were included in group A, whereas the type skulls ofT. truncatus, T. eurynome, andT. dawsoni were included in group B. This grouping was consistent with the genetic status. Therefore, we identified group A specimens asT. aduncus and group B specimensT. truncatus, the oldest scientific names related to the two groups.

The ability to identify delphinid vocalizations to species in real-time would be an asset during shipboard surveys. An automated system, Real-time Odontocete Call Classification Algorithm (ROCCA), is being developed to allow real-time acoustic species identification in the field. This Matlab-based tool automatically extracts ten variables (beginning, end, minimum and maximum frequencies, duration, slope of the beginning and end sweep, number of inflection points, number of steps, and presence/absence of harmonics) from whistles selected from a real-time scrolling spectrograph (ISHMAEL). It uses classification and regression tree analysis (CART) and discriminant function analysis (DFA) to identify whistles to species. Schools are classified based on running tallies of individual whistle classifications. Overall, 46% of schools were correctly classified for seven species and one genus (Tursiops truncatus, Stenella attenuata, S. longirostris, S. coeruleoalba, Steno bredanensis, Delphinus species, Pseudorca crassidens, and Globicephala macrorhynchus), with correct classification as high as 80% for some species. If classification success can be increased, this tool will provide a method for identifying schools that are difficult to approach and observe, will allow species distribution data to be collected when visual efforts are compromised, and will reduce the time necessary for post-cruise data analysis.

The taxonomic status of common dolphins (Delphinus sp.) remains controversial despite the increased number of studies focusing on its populations. Two species are presently recognized, Delphinus delphis and D. capensis. Apart from a phylogeographic study of the genus Delphinus, genetic studies focusing specifically in the northeast (NE) Atlantic remain scarce. Following ecological and morphological evidence for the existence of different common dolphin morphotypes in the Portuguese coast, we examined the population structure of D. delphis from the NE Atlantic by comparing DNA sequences from two mitochondrial regions (control region and cytochrome b gene). Additionally, we compared the sequences obtained with existing sequences of D. delphis from the Azores, Black Sea, Canary Islands, Pacific Ocean, D. capensis and also two closely related delphinid species (Stenella coeruleoalba and Tursiops truncatus). In the analysis of the NE Atlantic populations, we found evidence for the existence of some level of genetic differentiation. In the broader phylogenetic analysis, D. delphis and D. capensis did not show reciprocal monophyly and we found a group of highly divergent individuals. We discuss the possibility for the existence of two divergent lineages that have evolved independently, a separate subspecies or events of introgressive hybridization. These findings could have important implications on a taxonomic level, although further investigation based on a larger geographical scale and on nuclear loci information will certainly elucidate the origin of these highly divergent individuals.

Skulls of odontocetes (toothed whales, including dolphins and porpoises) are typified by directional asymmetry, particularly in elements associated with the airway. Generally, it is assumed this asymmetry is related to biosonar production. However, skull asymmetry may actually be a by-product of selection pressure for an asymmetrically positioned larynx. The odontocete larynx traverses the pharynx and is held permanently in place by a ring of muscle. This allows prey swallowing while remaining underwater without risking water entering the lungs and causing injury or death. However, protrusion of the larynx through the pharynx causes a restriction around which prey must pass to reach the stomach. The larynx and associated hyoid apparatus has, therefore, been shifted to the left to provide a larger right piriform sinus (lateral pharyngeal food channel) for swallowing larger prey items. This asymmetry is reflected in the skull, particularly the dorsal openings of the nares. It is hypothesized that there is a relationship between prey size and skull asymmetry. This relationship was examined in 13 species of odontocete cetaceans from the northeast Atlantic, including four narrow-gaped genera (Mesoplodon, Ziphius, Hyperoodon, and Kogia) and eight wide-gaped genera (Phocoena, Delphinus, Stenella, Lagenorhynchus, Tursiops, Grampus, Globicephala, and Orcinus). Skulls were examined from 183 specimens to assess asymmetry of the anterior choanae. Stomach contents were examined from 294 specimens to assess prey size. Results show there is a significant positive relationship between maximum relative prey size consumed and average asymmetry relative to skull size in odontocete species (wide-gape species: R2 = 0.642, P = 0.006; narrow-gape species: R2 = 0.909, P = 0.031). This finding provides support for the hypothesis that the directional asymmetry found in odontocete skulls is related to an aquatic adaptation enabling swallowing large, whole prey while maintaining respiratory tract protection.

The flukes of cetaceans function in the hydrodynamic generation of forces for thrust, stability, and maneuverability. The three-dimensional geometry of flukes is associated with production of lift and drag. Data on fluke geometry were collected from 19 cetacean specimens representing eight odontocete genera (Delphinus, Globicephala, Grampus, Kogia, Lagenorhynchus, Phocoena, Stenella, Tursiops). Flukes were imaged as 1 mm thickness cross-sections using X-ray computer-assisted tomography. Fluke shapes were characterized quantitatively by dimensions of the chord, maximum thickness, and position of maximum thickness from the leading edge. Sections were symmetrical about the chordline and had a rounded leading edge and highly tapered trailing edge. The thickness ratio (maximum thickness/chord) among species increased from insertion on the tailstock to a maximum at 20% of span and then decreasing steadily to the tip. Thickness ratio ranged from 0.139 to 0.232. These low values indicate reduced drag while moving at high speed. The position of maximum thickness from the leading edge remained constant over the fluke span at an average for all species of 0.285 chord. The displacement of the maximum thickness reduces the tendency of the flow to separate from the fluke surface, potentially affecting stall patterns. Similarly, the relatively large leading edge radius allows greater lift generation and delays stall. Computational analysis of fluke profiles at 50% of span showed that flukes were generally comparable or better for lift generation than engineered foils. Tursiops had the highest lift coefficients, which were superior to engineered foils by 12-19%. Variation in the structure of cetacean flukes reflects different hydrodynamic characteristics that could influence swimming performance.

The common dolphin has a widespread distribution and is relatively abundant in the temperate to subtropical waters of the eastern North Atlantic. However, it is not known whether different species, subspecies, or populations occur in this region. We examined 393 common dolphin skulls obtained from both stranded and bycaught individuals collected between 1901 and 2005. The series included skulls of 152 females and 199 males, from animals ranging in body length from 93 to 230 cm and 105 to 244 cm, respectively. The ranges of total body length, skull size, RL/ZGW ratio and maximum upper alveolar (tooth) count of common dolphins in the eastern North Atlantic overlapped with those of both short- (D. delphis) and long-beaked (D. capensis) species found off the Californian coast. However, in the absence of additional data, the common dolphin in the eastern North Atlantic is regarded here as a large form of Delphinus delphis. Sexual dimorphism and possible sex-linked characters were identified within the sample. Results of the current study

Sixty-five fatty acids were quantified in the blubber of common dolphins (Delphinus delphis, D. capensis) incidentally caught off the coast of southern California. Dolphins were grouped by sex, reproductive status and species, and a blubber sample was collected at a mid-lateral site located caudal to the trailing edge of the dorsal fin. Samples were divided horizontally into inner, middle and outer layers and gradients in fatty acid content (mass percent) were observed across the depth of the blubber. Levels of monounsaturated fatty acids were greatest in the outer layer, whereas levels of saturated and polyunsaturated fatty acids were greatest in the inner layer. Degree of stratification was greatest in sexually mature dolphins. Blubber of sexually immature, but physically mature, male dolphins was also highly stratified, suggesting that this difference may be attributed to differences in diet. Classification and regression tree analysis resulted in the fewest misclassifications when dolphins were grouped by species, possibly indicating that these closely related animals forage on different prey species. Dietary-derived fatty acids were typically selected as splitting criteria in classification and regression tree analyses, suggesting that the observed differences in fatty acid composition between the various groups of dolphins may be attributed to differences in diet.

Between 1970 and 2005 sightings data of cetaceans in the southern North Sea were collected as part of the Marine Mammal Database of the Dutch Seabird Group. The data include incidental sightings and reports as well as results from systematic surveys and seawatching data. They are therefore difficult to correct for fluctuations in observer effort. The material was evaluated firstly to see which species occur in Dutch waters and, secondly, to see if any spatial and temporal trends in abundance can be observed. In this study the harbour porpoise (Phocoena phocoena) is excluded from the analysis, except in the discussion, where the results are put into context with data about strandings and overall abundance. The status of the 17 different species that have been recorded in the southern North Sea between 1970 and 2005 was evaluated based on the frequency of occurrence of sightings (dead and alive) in the last 36 years. Two species were listed as resident (harbour porpoise and whitebeaked dolphin (Lagenorhynchus albirostris)), because they were abundant in 36 and 34 years respectively. The bottlenose dolphin (Tursiops truncatus), recorded in 23 years, was listed as a regular visitor or passage migrant. Ten species were qualified as irregular visitors (represented in 4-18 of the 36 years of study) and four as vagrants (recorded in