Ontogenetic development of the crinoid Poliometra prolixa in the Arctic deep sea

2021 ◽  
Author(s):  
Kirstin Meyer‐Kaiser ◽  
Amelia Smith ◽  
Thomas Soltwedel
2015 ◽  
Vol 32 (1) ◽  
pp. 149-170 ◽  
Author(s):  
Cara Nine

Abstract:Up until now, political philosophy has explained the acquisition of natural resources, in one way or another, through the terms of human settlement. An agent acquires natural resources by moving into the geographic area that contains these resources. Even how we make claims to the ocean floor depends on settlement — claimants must be adjacent to settled land. This essay extends original acquisition theories so that they can respond to cases that do not presuppose any conditions of human settlement. I suggest that resource rights in the deep sea may be created, alternatively, through acts of compromise. Compromise can alleviate conflict, allowing for claimants to move beyond stalemate to acquire goods. It also allows for a large degree of flexibility in the specification of rights, and thereby can explain nontraditional rights over areas of migration. The tricky part of a theory that grants rights through agreement is explaining why external parties, those not part of the agreement, have a duty to respect those rights. A compromise under certain conditions, I argue, places all persons under a duty to respect the rights created by the compromise. Thus, when two parties compromise, they may acquire goods from the commons — creating a duty for all others to respect the parties’ rights over these goods. Importantly, rights created through compromise are constrained by a set of concerns for those excluded.


Author(s):  
P. A. Tyler ◽  
J. D. Gage

INTRODUCTIONOphiacantha bidentata (Retzius) is a widespread arctic-boreal ophiuroid with a circumpolar distribution in the shallow waters of the Arctic seas and penetrating into the deep sea of the.North Atlantic and North Pacific (Mortensen, 1927, 1933a; D'yakonov, 1954). Early observations of this species were confined to defining zoogeo-graphical and taxonomic criteria including the separation of deep water specimens as the variety fraterna (Farran, 1912; Grieg, 1921; Mortensen, 1933a). Mortensen (1910) and Thorson (1936, pp. 18–26) noted the large eggs (o.8 mm diameter) in specimens from Greenland and Thorson (1936) proposed that this species had ‘big eggs rich in yolk, shed directly into the sea. Much reduced larval stage or direct development’. This evidence is supported by observations of O. bidentata from the White and Barents Seas (Semenova, Mileikovsky & Nesis, 1964; Kaufman, 1974)..


2009 ◽  
Vol 56 (10) ◽  
pp. 1856-1872 ◽  
Author(s):  
Thomas Soltwedel ◽  
Nina Jaeckisch ◽  
Nikolaus Ritter ◽  
Christiane Hasemann ◽  
Melanie Bergmann ◽  
...  
Keyword(s):  
Deep Sea ◽  

2020 ◽  
Vol 7 ◽  
Author(s):  
Mari Heggernes Eilertsen ◽  
Thomas G. Dahlgren ◽  
Hans Tore Rapp

ZooKeys ◽  
2018 ◽  
Vol 771 ◽  
pp. 15-40 ◽  
Author(s):  
Hiroshi Yamasaki ◽  
Katarzyna Grzelak ◽  
Martin V. Sørensen ◽  
Birger Neuhaus ◽  
Kai Horst George

Kinorhynchs rarely show a wide distribution pattern, due to their putatively low dispersal capabilities and/or limited sampling efforts. In this study, a new kinorhynch species is described,Echinoderespterussp. n., which shows a geographically and bathymetrically wide distribution, occurring on the Karasik Seamount and off the Svalbard Islands (Arctic Ocean), on the Sedlo Seamount (northeast Atlantic Ocean), and on the deep-sea floor off Crete and on the Anaximenes Seamount (Mediterranean Sea), at a depth range of 675–4,403 m. The new species is characterized by a combination of middorsal acicular spines on segments 4–8, laterodorsal tubes on segment 10, lateroventral tubes on segment 5, lateroventral acicular spines on segments 6–9, tufts of long hairs rising from slits in a laterodorsal position on segment 9, truncated tergal extensions on segment 11, and the absence of any type-2 gland cell outlet. The specimens belonging to the populations from the Arctic Ocean, the Sedlo Seamount, and the Mediterranean Sea show morphological variation in the thickness and length of the spines as well as in the presence/absence of ventromedial sensory spots on segment 7. The different populations are regarded as belonging to a single species because of their overlapping variable characters.


Paleobiology ◽  
1979 ◽  
Vol 5 (2) ◽  
pp. 107-125 ◽  
Author(s):  
Jennifer A. Kitchell

The foraging paradigm of trace fossil theory has historically accorded random behavior to non-food-limited deposit-feeders and non-random behavior to food-limited feeders. A series of randomness measures derived from empirical modeling, simulation modeling, stochastic modeling and probability theory applied to foraging patterns observed in deep-sea bottom photographs from the Arctic and Antarctic yielded a behavioral continuum of increasing non-randomness. A linear regression of trace positions along the continuum to bathymetric data did not substantiate the optimal foraging efficiency-depth dependence model of trace fossil theory, except that all traces exhibited a greater optimization than that of simulated random foraging. It is hypothesized that optimization as evidenced by non-random foraging strategies represents maximization of the cost/benefit ratio of resource exploitation to risk of predation and that individual foraging patterns reflect an exploration response to the morphometry of a patchily distributed food resource. Differential predation and competition may account for the co-occurrence of random and non-random strategies within the same bathymetric zone.


2008 ◽  
Vol 27 (2) ◽  
pp. 164-187 ◽  
Author(s):  
Torben Wolff

The Danish Ingolf Expedition took place in the summer months of 1895 and 1896, with C. F. Wandel as captain, a man with long experience in hydrographical work in the Arctic. The other scientific participants were the zoologists H. Jungersen, W. Lundbeck and H. J. Hansen during the 1895 cruise; C. Wesenberg-Lund replaced Hansen during the 1896 cruise. C. H. Ostenfeld was the botanist and M. Knudsen the hydrographer. The Ingolf (see Figure 1) was a naval cruiser. In both years the voyages were hindered by ice that had moved much further south than normal, even closing most of the Denmark Strait. In 1895, the best results were obtained south of Iceland and in the Davis Strait; in 1896 south and east of Iceland and as far north as Jan Mayen Island. A total of 144 stations were completed, all with soundings, trawlings and (for the first time) continuous hydrographical work associated with the deep-sea trawling (bottom measurements of temperature, salinity, chlorine contents and specific gravity). Eighty of the stations were deeper than 1,000 m. There were more than 800 hydrographical measurements, with about 3,300 registrations recordings added on the basis of the measurements. 138 gas analyses were performed on board with samples from the surface and the sea bottom. The main result of the expedition was the final demonstration of probably the most important threshold boundaries in the world: the Wyville Thompson Ridge from East Greenland to Scotland with maximum depths of 600 m, separating the fauna in the Norwegian and Polar Sea to the north, always with negative below-zero temperatures except close to the Norwegian coast, from the fundamentally different general Atlantic deep-sea fauna to the south of the ridge with positive temperatures. The results are published in the Ingolf Report, with fifteen volumes containing forty-three papers by nineteen Danish authors and fourteen papers by six foreign authors. The sieving technique was excellent—due to an apparatus designed by H. J. Hansen that kept the animals under water until preservation and using the finest silk for sieving. In this way, the expedition collected more smaller animals than had been acquired by previous deep-sea expeditions. Hansen's studies of the peracarid crustaceans and parasitic copepods and Lundbeck's report on the sponges were particularly noteworthy. The 130 photographs taken on board and on land by the ship's doctor William Thulstrup represent a cultural/historical treasure.


2006 ◽  
Vol 53 (7) ◽  
pp. 1167-1181 ◽  
Author(s):  
Sven Klimpel ◽  
Harry Wilhelm Palm ◽  
Markus Wilhelm Busch ◽  
Esra Kellermanns ◽  
Sonja Rückert

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