Slow pace of life of the Antarctic colossal squid

2010 ◽  
Vol 90 (7) ◽  
pp. 1375-1378 ◽  
Author(s):  
Rui Rosa ◽  
Brad A. Seibel
Keyword(s):  
High Speed ◽  
Cold Water ◽  
Morphological Characters ◽  
Routine Metabolic Rate ◽  
Predator Prey ◽  
Slow Pace ◽  
Large Size ◽  
Pace Of Life ◽  
Antarctic Waters ◽  
The Antarctic

The colossal squid (Mesonychoteuthis hamiltoni) is the world's largest invertebrate and its large size and some unique morphological characters have fuelled speculation that it is an aggressive top predator in the circum-Antarctic Southern Ocean. Here, we present estimates on the metabolic and energetic demands of this cold-water deep-sea giant. The estimated mass-specific routine metabolic rate for the colossal squid at 1.5°C was 0.036 µmol O2h−1g−1and the projected daily energy consumption (45.1 kcal day−1) was almost constant as a function of depth in the nearly isothermal Antarctic waters. Our findings also indicate the squid shows a slow pace of life linked with very low prey requirements (only 0.03 kg of prey per day). We argue that the colossal squid is not a voracious predator capable of high-speed predator–prey interactions. It is, rather, an ambush or sit-and-float predator that uses the hooks on its arms and tentacles to ensnare prey that unwittingly approach.

Re-evaluation of Graneledone setebos (Cephalopoda: Octopodidae) and allocation to the genus Megaleledone

2003 ◽  
Vol 83 (2) ◽  
pp. 319-328 ◽  
Author(s):  
A.L. Allcock ◽  
F.G. Hochberg ◽  
T.N. Stranks
Keyword(s):  
Southern Ocean ◽  
Comparative Study ◽  
Junior Synonym ◽  
New Combination ◽  
Museum Specimens ◽  
Large Size ◽  
Antarctic Waters ◽  
Marginal Plates ◽  
The Antarctic

The holotype of the Antarctic octopodid Graneledone setebos was re-examined and found to lack the epidermal warts characteristic of the genus Graneledone. It is similar in its large size to another Southern Ocean species, Megaleledonesenoi. A comparative study of G. setebos and specimens attributed to M. senoi led us to conclude that M. senoi is a junior synonym of G. setebos. Although M. senoi is not valid, the genus Megaleledone can be separated from other genera by the structure of the radula (which lacks marginal plates) and we therefore consider the genus to be valid. We propose the new combination of Megaleledone setebos and have refigured the beaks and radula of the holotype herein and expanded the description. A search of museum specimens and the literature shows that Megaleledone setebos is more common in Antarctic waters than previously supposed.

Diatom Fouling of the Little Picked Whales in the Antarctic Waters

2012 ◽  
Vol 48 (1) ◽  
pp. 28-34 ◽  
Author(s):  
V. L. Zinchenko ◽  
V. P. Gerasimyuk
Keyword(s):  
Antarctic Waters ◽  
The Antarctic

scholarly journals Salinity effects on cultured Neogloboquadrina pachyderma (sinistral) from high latitudes: new paleoenvironmental insights

2021 ◽  
Vol 41 (1) ◽  
Author(s):  
Jacqueline Bertlich ◽  
Nikolaus Gussone ◽  
Jasper Berndt ◽  
Heinrich F. Arlinghaus ◽  
Gerhard S. Dieckmann
Keyword(s):  
Sea Ice ◽  
Cold Water ◽  
Weddell Sea ◽  
Wall Thickening ◽  
High Latitudes ◽  
Neogloboquadrina Pachyderma ◽  
Antarctic Sea Ice ◽  
The Antarctic ◽  
Water Species ◽  
Cold Water Species

AbstractThis study presents culture experiments of the cold water species Neogloboquadrina pachyderma (sinistral) and provides new insights into the incorporation of elements in foraminiferal calcite of common and newly established proxies for paleoenvironmental applications (shell Mg/Ca, Sr/Ca and Na/Ca). Specimens were collected from sea ice during the austral winter in the Antarctic Weddell Sea and subsequently cultured at different salinities and a constant temperature. Incorporation of the fluorescent dye calcein showed new chamber formation in the culture at salinities of 30, 31, and 69. Cultured foraminifers at salinities of 46 to 83 only revealed chamber wall thickening, indicated by the fluorescence of the whole shell. Signs of reproduction and the associated gametogenic calcite were not observed in any of the culture experiments. Trace element analyses were performed using an electron microprobe, which revealed increased shell Mg/Ca, Sr/Ca, and Na/Ca values at higher salinities, with Mg/Ca showing the lowest sensitivity to salinity changes. This study enhances the knowledge about unusually high element concentrations in foraminifera shells from high latitudes. Neogloboquadrina pachyderma appears to be able to calcify in the Antarctic sea ice within brine channels, which have low temperatures and exceptionally high salinities due to ongoing sea ice formation.

scholarly journals Exercise Intensity and Technical Involvement in U9 Team Handball: Effect of Game Format

2021 ◽  
Vol 18 (11) ◽  
pp. 5663
Author(s):  
Georgios Ermidis ◽  
Rasmus C. Ellegard ◽  
Vincenzo Rago ◽  
Morten B. Randers ◽  
Peter Krustrup ◽  
...  
Keyword(s):  
Heart Rate ◽  
Locomotor Activity ◽  
Exercise Intensity ◽  
High Intensity ◽  
High Speed ◽  
Medium Size ◽  
Total Distance ◽  
Team Handball ◽  
Large Size ◽  
Game Format

The purpose of this study was to quantify the exercise intensity and technical involvement of U9 boys’ and girls’ team handball during different game formats, and the differences between genders. Locomotor activity (total distance, distance in speed zones, accelerations, and decelerations), heart rate (HR), and technical involvement (shots, goals, and duels) metrics were collected during various 15 min game formats from a total of 57 Danish U9 players (37 boys and 20 girls). Game formats were a small size pitch (20 × 13 m) with 3 vs 3 players and offensive goalkeepers (S3 + 1) and 4 vs 4 players (S4), a medium size pitch (25.8 × 20 m) with 4 vs 4 (M4) and 5 vs 5 (M5) players, and a large size pitch (40 × 20 m) with 5 vs 5 (L5) players. Boys and girls covered a higher total distance (TD) of high-speed running (HSR) and sprinting during L5 games compared to all other game formats (p < 0.05; ES = (−0.9 to −2.1), (−1.4 to −2.8), and (−0.9 to −1.3) respectively). Players covered the highest amount of sprinting distance in L5 games compared to all other game formats (p < 0.01; ES = 0.8 to 1.4). In all the game formats, players spent from 3.04 to 5.96 min in 180–200 bpm and 0.03 min to 0.85 min in >200 bpm of the total 15 min. In addition, both genders had more shots in S3 + 1 than M5 (p < 0.01; ES = 1.0 (0.4;1.7)) and L5 (p < 0.01; ES = 1.1 (0.6;2.2)). Team handball matches have high heart rates, total distances covered, and high-intensity running distances for U9 boys and girls irrespective of the game format. Locomotor demands appeared to be even higher when playing on larger pitches, whereas the smaller pitch size and fewer players led to elevated technical involvement.

scholarly journals Optical Encryption Based on Computer Generated Holograms in Photopolymer

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1358
Author(s):  
Taihui Wu ◽  
Jianshe Ma ◽  
Chengchen Wang ◽  
Haibei Wang ◽  
Liangcai Cao ◽  
...  
Keyword(s):  
High Speed ◽  
Three Dimensional ◽  
Angular Spectrum ◽  
Quick Response ◽  
Response Code ◽  
Optical Encryption ◽  
Large Size ◽  
Quick Response Code ◽  
Computer Generated Holograms ◽  
Encryption Method

An optical encryption method based on computer generated holograms printing of photopolymer is presented. Fraunhofer diffraction is performed based on the Gerchberg-Saxton algorithm, and a hologram of the Advanced Encryption Standard encrypted Quick Response code is generated to record the ciphertext. The holograms of the key and the three-dimensional image are generated by the angular spectrum diffraction algorithm. The experimental results show that large-size encrypted Quick Response (QR) code and miniature keys can be printed in photopolymers, which has good application prospects in optical encryption. This method has the advantages of high-density storage, high speed, large fault tolerance, and anti-peeping.

Observations on moulting in Antarctic Krill (Euphausia superba Dana)

1982 ◽  
Vol 33 (1) ◽  
pp. 71 ◽  
Author(s):  
T Ikeda ◽  
P Dixon
Keyword(s):  
Phaeodactylum Tricornutum ◽  
Antarctic Krill ◽  
Dry Weight ◽  
Euphausia Superba ◽  
Dunaliella Tertiolecta ◽  
Antarctic Ocean ◽  
Fish Food ◽  
Antarctic Waters ◽  
The Antarctic ◽  
Antarctic Krill Euphausia Superba

Live E. superba were transported from Antarctic waters to a tropical laboratory where observations at the temperature of -0.5�C (0 to - 1.0�C), were made of intermoult period of specimens fed a mixture of microalgae (Dunaliella tertiolecta and Phaeodactylum tricornutum) or artificial pet fish food or starved. Mean intermoult period was 26.4-27.1 days for fed specimens and 29.6 days for starved specimens, with no relation to the size of specimens. The moult accounted for a loss of 2.63-4.35% of animal dry weight, which is equivalent to 1.1-1.8% of animal nitrogen or 1.4-2.3% of animal carbon. The contribution of moults to detritus in the Antarctic Ocean was estimated as 0.11 g C m-2 per year.

scholarly journals Sea State Monitoring by Ship Motion Measurements Onboard a Research Ship in the Antarctic Waters

2021 ◽  
Vol 9 (1) ◽  
pp. 64
Author(s):  
Silvia Pennino ◽  
Antonio Angrisano ◽  
Vincenzo Della Corte ◽  
Giampaolo Ferraioli ◽  
Salvatore Gaglione ◽  
...  
Keyword(s):  
Transfer Functions ◽  
Wave Spectrum ◽  
Weather Forecast ◽  
Ship Motion ◽  
State Monitoring ◽  
Sea State ◽  
Peak Period ◽  
Research Ship ◽  
Antarctic Waters ◽  
The Antarctic

A parametric wave spectrum resembling procedure is applied to detect the sea state parameters, namely the wave peak period and significant wave height, based on the measurement and analysis of the heave and pitch motions of a vessel in a seaway, recorded by a smartphone located onboard the ship. The measurement system makes it possible to determine the heave and pitch acceleration spectra of the reference ship in the encounter frequency domain and, subsequently, the absolute sea spectra once the ship motion transfer functions are provided. The measurements have been carried out onboard the research ship “Laura Bassi”, during the oceanographic campaign in the Antarctic Ocean carried out in January and February 2020. The resembled sea spectra are compared with the weather forecast data, provided by the global-WAM (GWAM) model, in order to validate the sea spectrum resembling procedure.

A large new species of Rhinella (Anura: Bufonidae) from Cerrado of Brazil

Zootaxa ◽  
2007 ◽  
Vol 1627 (1) ◽  
pp. 23-39 ◽  
Author(s):  
NATAN M. MACIEL ◽  
REUBER A. BRANDÃO ◽  
LEANDRO A. CAMPOS ◽  
ANTONIO SEBBEN
Keyword(s):  
Phylogenetic Analysis ◽  
New Species ◽  
Morphological Characters ◽  
Morphological Features ◽  
Advertisement Call ◽  
Sexually Dimorphic ◽  
Rhinella Marina ◽  
Large Size ◽  
Morphometric Feature ◽  
Distrito Federal

A new toad, Rhinella cerradensis, is described, including its tadpole and the advertisement call. The new species occupies Cerrado habitats in the Brazilian states of Piauí, Bahia, Goiás, Minas Gerais, and Distrito Federal. The species is characterized by its large size; absence of tibial glands; well developed cranial crests; short hands; sexually dimorphic coloration; and by the absence of a spiracle tube of the tadpole. The new species is included in the Rhinella marina group by the presence of a jagged suture formed by the articulation between the pterygoid medial ramus and the parasphenoid alae, as well as other shared morphological features. Morphological characters and statistical analyses inferred by morphometric feature suggest the existence of two subgroups of species within R. marina group. However, taxonomic rearrangements are not made here and await phylogenetic analysis.

A giant within Carpocorini (Hemiptera: Heteroptera: Pentatomidae): Description of Adustonotus graziae sp. nov.

Zootaxa ◽  
2021 ◽  
Vol 4958 (1) ◽  
pp. 489-502
Author(s):  
FILIPE MICHELS BIANCHI
Keyword(s):  
Morphological Characters ◽  
The Other ◽  
Total Evidence ◽  
Valid Species ◽  
Phylogenetic Position ◽  
New Taxon ◽  
Large Size ◽  
Internal Genitalia ◽  
Evidence Analysis ◽  
Heteroptera Pentatomidae

The Carpocorini are distributed worldwide, and it is one of the most speciose tribes within the Pentatomidae with 127 genera and more than 500 valid species. Recently, Adustonotus Bianchi was described to contain eight species formerly placed within Euschistus Dallas. Among them, Adustonotus grandis (Rolston) and Adustonotus latus (Dallas) are remarkable for their large size. Herein, the phylogenetic position of a new taxon is inferred by a total evidence analysis based on 85 morphological characters and four molecular markers. Adustonotus graziae sp. nov. is described, and is recovered in a polytomic lineage, including A. grandis and A. latus. These species share a solid combination of features that enable them to be separated from the other Adustonotus species (e.g., large size, the humeral angles spatulate and exceptionally produced, and the capsula seminalis shortened). Illustrations of external and internal genitalia, and a distributional map are provided. 

Experimental Analysis of Water/Oil Displacement Tests in Horizontal Pipe

SPE Journal ◽  
2021 ◽  
pp. 1-18
Author(s):  
Roberto Fernando Leuchtenberger ◽  
Jorge Luiz Biazussi ◽  
William Monte Verde ◽  
Marcelo de Souza Castro ◽  
Antonio Carlos Bannwart
Keyword(s):  
Viscous Liquid ◽  
High Speed ◽  
Cold Water ◽  
Tap Water ◽  
Logistic Function ◽  
Oil Field ◽  
Injection Velocity ◽  
Internal Diameter ◽  
Oil Viscosity ◽  
Horizontal Pipe

Summary Production shutdowns occur often throughout the life cycle of an oil field. In offshore fields, shutdown situations are accompanied by an intense heat exchange between pipeline and cold water, which exponentially increases oil viscosity. Such an event may lead to serious difficulty to restart the production, or even render it unfeasible, especially for heavy oil fields. Therefore, a preventive procedure is required to remove the ultraviscous oil from pipelines and risers; for example, by pumping diesel or methanol in a flush procedure. Designing an efficient cleanup procedure is therefore essential in terms of time, amount of fluid injected, and pumping system requirements. However, the amount of research published in this area is limited. In this paper, we propose a comprehensive analysis on how the displacement of a viscous liquid by a less-viscous liquid occurs in a pipeline through footages in different segments, varying the injection velocity. Two mineral oils with different viscosities and tap water were used as working fluids for this study. The experimental setup was built with a horizontal 10-m-long acrylic pipe with 19-mm internal diameter. Two high-speed cameras were placed both in the inlet and outlet segments. Our results demonstrate how water displaces viscous oil in a pipeline, showing different flow configurations as superficial water velocity increases, depending on the oil viscosity and distance from the inlet. A dimensionless analysis was performed by a combination of the forces that govern the flow and dimensionless groups found in literature. The results show an expected area of optimum values regarding cleaning time according to flow configuration. A unidimensional model using a logistic function was proposed and showed a good agreement with the experimental data. The model itself proven to be an easy tool for industry and academic purposes, supporting even more robust and elaborated models in the future. NOTE: Supplemental material is available with this paper and is available online under the Supplementary Data heading at https://doi.org/10.2118/205356-PA.

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