Delaware Museum of Natural History

Wilmington, Delaware, United States

Delaware Museum of Natural History

Wilmington, Delaware, United States
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Shea E.K.,Delaware Museum of Natural History | Judkins H.,University of South Florida | Staudinger M.D.,University of Missouri | Staudinger M.D.,University of Massachusetts Amherst | And 4 more authors.
Marine Biodiversity | Year: 2017

Bear Seamount (BSM) is the most inshore seamount in the New England Seamount chain. It is located within the U.S. Exclusive Economic Zone and is contained within the recently established Northeast Canyons and Seamounts Marine National Monument. In 2000, the National Oceanic and Atmospheric Administration’s (NOAA) National Systematics Laboratory began an exploratory trawling program to document nekton diversity at BSM and its vicinity. Here, we summarize eight exploratory sampling cruises conducted between 2000 and 2014, and describe the cephalopod biodiversity and assemblage structure around BSM. Over the course of 174 deep–midwater and 56 bottom tows, 5088 cephalopods were identified, measured, and documented. In total, 77 species were collected at BSM; 75 species were collected from midwater tows and 28 from benthic tows. Rarefaction curves did not reach an asymptote, suggesting that additional sampling will collect more species. Seventeen species accounted for 75% of the total midwater and bottom catch, including: Illex illecebrosus (n = 605), Magnoteuthis magna (n = 568), Abraliopsis morisii (n = 518), Abralia redfieldi (n = 358), Mastigoteuthis agassizii (n = 336), Histioteuthis reversa (n = 273), Taonius pavo (n = 239), Haliphron atlanticus (n = 195), Brachioteuthis beanii (n = 160), Ornithoteuthis antillarum (n = 153), Pterygioteuthis gemmata (n = 141), Pyroteuthis margaritifera (n = 120), Vampyroteuthis infernalis (n = 101), Chiroteuthis veranyi (n = 33), Bolitaena pygmaea (n = 30), Graneledone verrucosa (n = 11), and Stauroteuthis syrtensis (n = 29). Non-metric multidimensional scaling (NMDS) of significant analysis of similarity (ANOSIM) results showed that the 2000 cruise was different from other years, meteorological winter was different from other seasons, and that day and night shallow samples were different from each other and all other depths. Based on seasonal size variation in the most abundant taxa, we propose hypotheses of year-round, winter, and spring spawning for future critical assessment. This extensive description of the offshore cephalopod assemblage may be used to assess vulnerability to future environmental changes and human activities. © 2017 Senckenberg Gesellschaft für Naturforschung and Springer-Verlag Berlin Heidelberg


Kelly N.E.,Bedford Institute of Oceanography | Kelly N.E.,York University | Shea E.K.,Delaware Museum of Natural History | Metaxas A.,Dalhousie University | And 2 more authors.
PLoS ONE | Year: 2010

Background: In contrast to the well-studied continental shelf region of the Gulf of Maine, fundamental questions regarding the diversity, distribution, and abundance of species living in deep-sea habitats along the adjacent continental margin remain unanswered. Lack of such knowledge precludes a greater understanding of the Gulf of Maine ecosystem and limits development of alternatives for conservation and management. Methodology/Principal Findings: We use data from the published literature, unpublished studies, museum records and online sources, to: (1) assess the current state of knowledge of species diversity in the deep-sea habitats adjacent to the Gulf of Maine (39-43°N, 63-71°W, 150-3000 m depth); (2) compare patterns of taxonomic diversity and distribution of megafaunal and macrofaunal species among six distinct sub-regions and to the continental shelf; and (3) estimate the amount of unknown diversity in the region. Known diversity for the deep-sea region is 1,671 species; most are narrowly distributed and known to occur within only one sub-region. The number of species varies by sub-region and is directly related to sampling effort occurring within each. Fishes, corals, decapod crustaceans, molluscs, and echinoderms are relatively well known, while most other taxonomic groups are poorly known. Taxonomic diversity decreases with increasing distance from the continental shelf and with changes in benthic topography. Low similarity in faunal composition suggests the deep-sea region harbours faunal communities distinct from those of the continental shelf. Non-parametric estimators of species richness suggest a minimum of 50% of the deep-sea species inventory remains to be discovered. Conclusions/Significance: The current state of knowledge of biodiversity in this deep-sea region is rudimentary. Our ability to answer questions is hampered by a lack of sufficient data for many taxonomic groups, which is constrained by sampling biases, life-history characteristics of target species, and the lack of trained taxonomists. © 2010 Kelly et al.


Xavier J.C.,University of Coimbra | Xavier J.C.,Natural Environment Research Council | Allcock A.L.,National University of Ireland | Cherel Y.,CNRS Chizé Center for Biological Studies | And 10 more authors.
Journal of the Marine Biological Association of the United Kingdom | Year: 2015

Cephalopods (Mollusca: Cephalopoda) play an important role as keystone invertebrates in various marine ecosystems, as well as being a valuable fisheries resource. At the World Malacological Congress, held 21-28 July 2013 in Ponta Delgada, Azores, Portugal, a number of cephalopod experts convened to honour the contribution of the late Malcolm R. Clarke, FRS (1930-2013) to cephalopod research. Endorsed by the Cephalopod International Advisory Council (CIAC), the meeting discussed some of the major challenges that cephalopod research will face in the future. These challenges were identified as follows: (1) to find new ways to ascertain the trophic role and food web links of cephalopods using hard tissues, stable isotopes and novel concepts in theoretical ecology; (2) to explore new approaches to the study of cephalopod morphology; (3) to further develop cephalopod aquaculture research; (4) to find new ways to ascertain cephalopod adaptation and response to environmental change; (5) to strengthen cephalopod genetics research; and (6) to develop new approaches for cephalopod fisheries and conservation. The present paper presents brief reviews on these topics, followed by a discussion of the general challenges that cephalopod research is bound to face in the near future. By contributing to initiatives both within CIAC and independent of CIAC, the principle aim of the paper is to stimulate future cephalopod research. Copyright © Marine Biological Association of the United Kingdom 2014.


Xavier J.C.,University of Coimbra | Xavier J.C.,Natural Environment Research Council | Allcock A.L.,National University of Ireland | Cherel Y.,CNRS Chizé Center for Biological Studies | And 9 more authors.
Journal of the Marine Biological Association of the United Kingdom | Year: 2014

Cephalopods (Mollusca: Cephalopoda) play an important role as keystone invertebrates in various marine ecosystems, as well as being a valuable fisheries resource. At the World Malacological Congress, held 21-28 July 2013 in Ponta Delgada, Azores, Portugal, a number of cephalopod experts convened to honour the contribution of the late Malcolm R. Clarke, FRS (1930-2013) to cephalopod research. Endorsed by the Cephalopod International Advisory Council (CIAC), the meeting discussed some of the major challenges that cephalopod research will face in the future. These challenges were identified as follows: (1) to find new ways to ascertain the trophic role and food web links of cephalopods using hard tissues, stable isotopes and novel concepts in theoretical ecology; (2) to explore new approaches to the study of cephalopod morphology; (3) to further develop cephalopod aquaculture research; (4) to find new ways to ascertain cephalopod adaptation and response to environmental change; (5) to strengthen cephalopod genetics research; and (6) to develop new approaches for cephalopod fisheries and conservation. The present paper presents brief reviews on these topics, followed by a discussion of the general challenges that cephalopod research is bound to face in the near future. By contributing to initiatives both within CIAC and independent of CIAC, the principle aim of the paper is to stimulate future cephalopod research. Copyright © Marine Biological Association of the United Kingdom 2014.


Shea E.K.,Delaware Museum of Natural History | Vecchione M.,National Oceanic and Atmospheric Administration
ICES Journal of Marine Science | Year: 2010

Planktonic and newly hatched cephalopods are routinely called paralarvae. Currently, the onset of diel vertical migration (DVM) marks the end of the paralarval phase, although changes in ontogenic growth trajectories may also be used. Patterns of DVM are reported for the first time for three poorly understood mesopelagic squid species. Discrete-depth samples taken during the Amsterdam Mid North Atlantic Plankton Expeditions (AMNAPE) of 1980-1983 are used to examine the timing of ecological and morphological changes in Chtenopteryx sicula, Mastigoteuthis magna, and Brachioteuthis sp. 3. DVM patterns are species-specific, and ontogenic changes in DVM coincide with allometric changes in the arm, fin, and funnel characters of C. sicula at 7 mm mantle length. Mastigoteuthis magna is not concentrated in the upper 250 m of the water column during the day, and no clear DVM pattern is found in Brachioteuthis sp. 3, meaning that the endpoint of the paralarval phase cannot be defined ecologically in these species. Other ecological transformations, e.g. changes in prey-capture ability, are therefore explored as alternatives to DVM. The pad-shaped club and long neck are proposed as visual markers of the end of the paralarval phase of C. sicula and Brachioteuthis sp. 3, respectively. © 2010 International Council for the Exploration of the Sea. Published by Oxford Journals. All rights reserved.


Roper C.F.E.,Smithsonian Institution | Judkins H.,University of South Florida | Voss N.A.,University of Miami | Shea E.,Delaware Museum of Natural History | And 4 more authors.
American Malacological Bulletin | Year: 2014

This report provides information on 28 specimens of the giant squid, Architeuthis dux (Steenstrup 1857), discovered in the western North Atlantic Ocean between Newfoundland and the Gulf of Mexico. Some specimens have been reported in the press or popular literature, but others are recorded herein for the first time. Nominal architeuthid species are provided as well as tables listing repositories of types of nominal species, and repositories of non-type specimens from the study area. An extensive list of references of pertinent regional literature is provided, and recommendations for fixation and preservation are described.


Roper C.F.E.,Smithsonian Institution | Shea E.K.,Delaware Museum of Natural History
American Malacological Bulletin | Year: 2013

The giant squid, Architeuthis Steenstrup, 1857, serves as a model for what we know and do not know about the broad biological aspects of the coleoid cephalopods. Gaps in our knowledge of taxonomy and systematics, distribution, population size, habitat use, age and growth, predation and feeding, reproduction and life cycles, and functional morphology all are examined by our review of Architeuthis natural history. Continued Architeuthis research improves our understanding of all coleoid cephalopods, and provides an avenue to engage the public in the process of science.

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