A preliminary investigation of the lipids of abyssal holothurians from the north-east Atlantic Ocean

Author(s):  
Michael L. Ginger ◽  
Vera L.C.S. Santos ◽  
George A. Wolff

The dominant lipids of seven species of abyssal holothurians (Oneirophanta mutabilis, Pseudostichopus villosus, Psychropotes longicauda, Deima validium, Parariza prouhoi, Amperima rosea and Molpadia blakei) have been examined in detail. Fatty acid compositions are qualitatively similar to those of shallow-water holothurians, but relatively higher amounts of unsaturated compounds in the deep sea animals are ascribed to an adaptation of the latter to maintain membrane fluidity at high pressure and low temperature. The sterol distributions of abyssal holothurians are complex, with mixtures of C26–C30 sterols being present in all of the animals. These are most likely to be dietary in origin; the holothurians substitute Δ5 with Δ7 unsaturation, via Δ5,7 or Δ0 intermediates. 14α-methylcholest-9(11)-enol, which is a common product of de novo biosynthesis in shallow-water holothurians is absent in all of the deep-water species. Furthermore, cholest-7-enol, the dominant product of de novo biosynthesis in shallow water animals, is a relatively minor component in all of the species, except A. rosea. This holothurian is also the only one that appears to assimilate 4α-methylsterols directly and contains high amounts of steryl sulphates. There are significant interspecies differences in the free sterol distributions which may reflect their different feeding strategies or niches.

2000 ◽  
Vol 79 (2-3) ◽  
pp. 335-343 ◽  
Author(s):  
Marit-Solveig Seidenkrantz ◽  
Karen Luise Knudsen ◽  
Peter Kristensen

AbstractThe marine Eemian (marine oxygen-isotope substage 5e: MIS 5e) is represented by shallow-water deposits in southern and western Denmark, while relatively deep-water environments occurred to the north and north-east, where complete interglacial successions seem to be present. We present an overview of the marine Eemian deposits in Denmark, and discuss in more detail indications of climate variability, both for the late Saalian and within the Eemian.


Author(s):  
Andrés Arias ◽  
Hannelore Paxton

AbstractRhamphobrachium (Rhamphobrachium) agassizii is reported from the Cantabrian Sea, Spain, from depths of 925–1207 m. This is its first record off the Iberian Peninsula and in European waters, representing its northernmost distribution in the North Atlantic Ocean to date. Previous reports of R. (R.) agassizii from the eastern and western North Atlantic demonstrate its apparent amphi-Atlantic distribution, which appears consistent with the distribution of the main Atlantic currents. It is a typical deep-water species with its deepest record at 2165 m from the Azores archipelago. The specimens were collected singly at two stations, attesting to the rarity of the species in contrast to its congener R. (Spinigerium) brevibrachiatum which was the most dominant polychaete species in a previous study.


Zootaxa ◽  
2019 ◽  
Vol 4565 (2) ◽  
pp. 201 ◽  
Author(s):  
ZHIBIN GAN ◽  
XINZHENG LI

Four deep-water species of stalked barnacles were collected by the manned submersibles Jiaolong and Shenhaiyongshi during recent expeditions. Trianguloscalpellum regium (Wyville-Thomson, 1873), collected from the Mariana Trench at a depth of 5,462 m, represents a new distribution record. Glyptelasma gigas (Annandale, 1916), Poecilasma litum Pilsbry, 1907 and Poecilasma obliqua Hoek, 1907, collected from the South China Sea, are recorded for the first time from a mud volcano environment. Detailed photographs of these four species are presented and their partial sequences of 16S rRNA and mt COI genes are provided. 


Author(s):  
J. Mauchline

The seasonal maxima of occurrence of 23 species of mysids are examined; the numbers caught of a further four species were too small to draw any conclusions from. The evidence suggests that all species, except possibly two, aggregate; not enough information is available on Acanthomysis longicornis and Heteromysis fortnosa. The types of aggregations formed, whether population swarms or breeding aggregations, are unknown in 10 species. There is evidence of shoal and/or swarmformation in 12 species and of breeding aggregations in 7 species. All species known to form swarms live in shallow water; Leptomysis gracilis is the only species living in deep water that shows evidence of swarm formation. All other deep-water species aggregate, some for the purposes of breeding. Negative phototropism of individuals is suggested as a mechanism initiating aggregation of species in the bottom of deep-water basins. Reaction of one individual to another individual or groupof individuals (social behaviour) is considered necessary to intensify the initial degrees of aggregation and to maintain the integrity of shoals or breeding aggregations once formed. Parallels are drawn between aggregations of mysids and those of euphausiids.


Author(s):  
Iván Enrique Caycedo

Systematic and ecological remarks are presented on 14 species of shallow water holothurians of the northern coast of Colombia. The material was collected from Islas del Rosario off the coast southwest of Cartagena (10° 08' 39" Lat. N 75° 43, 21" Long. W) and from Tayrona National Park to the north east of Santa Marta (11° 20, Lat. N and 74 05, Long. W). Ten species are new records to Colombia, one of them appeared to be undescribed as yet (Holothuria thomaú sp. nov. Pawson & Caycedo, in preparation). A key to these species is given. The occurrence of some species in abundance in different habitats is discussed in order to elucidate ecological interrelationships and facilitate field identification.


1990 ◽  
Vol 38 ◽  
pp. 11-32
Author(s):  
R. A. Fortey ◽  
]. S. Peel

A well-preserved, shallow water bathyurid trilobite fauna of early Ordovician age, and associated gastropods and an undetermined hyolith are described from the Poulsen Cliff Formation of Washington Land, western North Greenland. Two new bathyurid species, Licnocephala sminue and Pe/tabellia elegans, and a new gastropod species, Plethospira(?) floweri, are described. Biolgina Maximova is considered a junior subjective synonym of Peltabellia Whittington. The distribution of the genus is an example of close relationship between shallow water trilobite faunas of Laurentia and the North-east Siberian platform in the early Ordovician.


Author(s):  
Gennady M. Kamenev

Three new species, Hyalopecten vityazi sp. nov., H. abyssalis sp. nov. and H. kurilensis sp. nov., are described from the abyssal and hadal zones of the North-western Pacific. Hyalopecten vityazi was found in the Kuril-Kamchatka and Aleutian trenches at 6090–8100 m depth. It is the most deep-water species of the order Pectinida. Hyalopecten abyssalis and H. kurilensis were found at the abyssal plain adjacent to the Kuril-Kamchatka and Aleutian trenches at 4550–5045 m depth. To date, 13 species of the genus Hyalopecten are known from different regions of the World Ocean. A table with the main differences among all known species in the genus is provided.


Oryx ◽  
1966 ◽  
Vol 8 (4) ◽  
pp. 221-222 ◽  
Author(s):  
Colin Bertram ◽  
Kate Bertram

In their 1965 survey of dugongs on the north-east Australian coast, Dr. Colin and Dr. Kate Bertram made the welcome discovery that these aquatic mammals, whose numbers were seriously reduced throughout their range in the last century and the early decades of this, are now holding their own here and may even in a few places be increasing. Dugong meat and oil are highly valued by some Australian native people, and the animals fill an important ecological niche as consumers of aquatic plants in shallow water.


Author(s):  
Joana Xavier ◽  
Rob van Soest

Seamounts, although abundant features of the world's oceans, constitute one of the least studied marine ecosystems. In the present work we assessed the diversity and zoogeographical affinities of the demosponge assemblages of Gettysburg and Ormonde Seamounts (Gorringe Bank, north-east Atlantic). Twenty-three demosponge species were identified adding to the thirteen previously reported for Gorringe shallow-water. Gorringe's demosponge assemblage was found to be mainly composed of species with a wide Atlanto–Mediterranean distribution (61%) and a group of species (28%) that are endemic to this Bank or have a restricted geographical distribution. This high level of endemism suggests the Gorringe Bank as a hotspot for demosponge fauna in the north-east Atlantic. Gorringe demosponge fauna was found to present an overall moderate similarity to the Mediterranean, Iberian coasts and Macaronesian archipelagos. We compare our findings with patterns reported for fish and molluscan faunas for this Bank and discuss some evolutionary aspects on the role of these ecosystems for the north-east Atlantic marine biota.


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