scholarly journals The Roles of Spinochromes in Four Shallow Water Tropical Sea Urchins and Their Potential as Bioactive Pharmacological Agents

Marine Drugs ◽  
2017 ◽  
Vol 15 (6) ◽  
pp. 179 ◽  
Author(s):  
Lola Brasseur ◽  
Elise Hennebert ◽  
Laurence Fievez ◽  
Guillaume Caulier ◽  
Fabrice Bureau ◽  
...  
Keyword(s):  
Shallow Water ◽  
Sea Urchins ◽  
Pharmacological Agents ◽  
Tropical Sea

Survival of seaweeds ingested by three species of tropical sea urchins from Brazil

Hydrobiologia ◽  
1991 ◽  
Vol 222 (1) ◽  
pp. 13-17 ◽  
Author(s):  
Mariana Cabral de Oliveira
Keyword(s):  
Sea Urchins ◽  
Tropical Sea

Suspension freezing of bottom sediment and biota in the Northwest Passage and implications for Arctic Ocean sedimentation

1992 ◽  
Vol 29 (4) ◽  
pp. 693-703 ◽  
Author(s):  
Erk Reimnitz ◽  
Louie Marincovich Jr. ◽  
Michael McCormick ◽  
W. M. Briggs
Keyword(s):  
Arctic Ocean ◽  
Shallow Water ◽  
Sea Urchins ◽  
The Arctic ◽  
River Flooding ◽  
Northwest Passage ◽  
Beaufort Gyre ◽  
Transpolar Drift ◽  
Living Organisms ◽  
Northern Alaska

Ice observations and sediment collected in a summer transit through the Northwest Passage provide insights on suspension freezing, the most important sediment entrainment mechanism for the Arctic Ocean. No evidence was seen for entrainment by bottom adfreezing, bluff slumping, river flooding, dragging ice keels, or significant eolian transport from land to sea. Lack of eolian sediment loading in the Northwest Passage, together with that already reported for northern Alaska, eliminates wind as an important source for fine sediment in the pack of the Beaufort Gyre and related parts of the Transpolar Drift. Muddy sediment with pebbles and cobbles, algae with holdfasts, ostracodes with appendages, and well-preserved mollusks and sea urchins were collected from two sites in a 50 km long stretch of turbid ice. These materials indicate that suspension freezing reaching to a water depth of 25–30 m during the previous fall was responsible for entrainment. This mechanism requires rapid ice formation in open, shallow water during a freezing storm, when the ocean becomes supercooled, and frazil and anchor ice attach to and ultimately lift sediment and living organisms to the sea surface. The mechanism, already known to be important in the Beaufort Sea, probably also affects wide, shallow Siberian shelves and leads to cross-shelf transport of shallow-water organisms and dropstones with "glacial striations" toward deep basins. This makes distinguishing glacial–interglacial cycles more difficult.

scholarly journals Size, growth, and density data for shallow-water sea urchins from Mexico to the Aleutian Islands, Alaska, 1956-2016

Ecology ◽  
2018 ◽  
Vol 99 (3) ◽  
pp. 761-761 ◽  
Author(s):  
Thomas A. Ebert ◽  
Louis M. Barr ◽  
James L. Bodkin ◽  
Dirk Burcham ◽  
Dominique Bureau ◽  
...  
Keyword(s):  
Shallow Water ◽  
Sea Urchins ◽  
Aleutian Islands ◽  
Density Data ◽  
Size Growth

scholarly journals Embryonic, Larval, and Early Juvenile Development of the Tropical Sea Urchin,Salmacis sphaeroides(Echinodermata: Echinoidea)

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
M. Aminur Rahman ◽  
Fatimah Md. Yusoff ◽  
A. Arshad ◽  
Mariana Nor Shamsudin ◽  
S. M. N. Amin
Keyword(s):  
Sea Urchins ◽  
Morphological Changes ◽  
Sperm Concentration ◽  
Fertilization Rate ◽  
Life History Strategies ◽  
Early Juvenile ◽  
Culture Techniques ◽  
Unicellular Algae ◽  
Tropical Sea ◽  
Juvenile Development

Salmacis sphaeroides(Linnaeus, 1758) is one of the regular echinoids, occuring in the warm Indo-West Pacific, including Johor Straits, between Malaysia and Singapore. In order to investigate the developmental basis of morphological changes in embryos and larvae, we documented the ontogeny ofS. sphaeroidesin laboratory condition. Gametes were obtained from adult individuals by 0.5 M KCl injection into the coelomic cavity. Fertilization rate at limited sperm concentration (10−5dilution) was96.6±1.4% and the resulting embryos were reared at 24°C. First cleavage (2-cell), 4-cell, 8-cell, 16-cell, 32-cell, and multicell (Morulla) stages were achieved 01.12, 02.03, 02.28, 02.51, 03.12, and 03.32 h postfertilization. Ciliated blastulae with a mean length of174.72±4.43 μm hatched 08.45 h after sperm entry. The gastrulae formed 16.15 h postfertilization and the archenteron elongated constantly while ectodermal red-pigmented cells migrated synchronously to the apical plate. Pluteus larva started to feed unicellular algae in 2 d, grew continuously, and finally attained metamorphic competence in 35 d after fertilization. Metamorphosis took approximately 1 h 30 min from attachment to the complete resorption of larval tissues and the development of complete juvenile structure with adult spines, extended tubefeet and well-developed pedicellaria, the whole event of which usually took place within 1 d postsettlement. This study represents the first successful investigation on embryonic, larval, and early juvenile development ofS. sphaeroides. The findings would greatly be helpful towards the understanding of ontogeny and life-history strategies, which will facilitate us to develop the breeding, seed production, and culture techniques of sea urchins in captive condition.

Habitat selection by common eiders in winter and its interaction with flock size

1993 ◽  
Vol 71 (6) ◽  
pp. 1259-1266 ◽  
Author(s):  
Magella Guillemette ◽  
John H. Himmelman ◽  
Cyrille Barette ◽  
Austin Reed
Keyword(s):  
Habitat Selection ◽  
Shallow Water ◽  
Prey Density ◽  
Sea Urchins ◽  
Day Length ◽  
Antipredator Behaviour ◽  
Somateria Mollissima ◽  
Flock Size ◽  
Eastern Canada ◽  
Diving Depth

We studied habitat selection in relation to prey density and water depth in the common eider, Somateria mollissima L., wintering in the Gulf of St. Lawrence, eastern Canada. In this region, eiders are confronted with low temperatures, ice cover, and reduced day length. We predicted that they should select feeding habitats characterized by high prey density and shallow water to minimize the time and energy spent while diving. About 1000 flocks were localized by triangulation on our study site (20.5 km2). We inferred the diving depth and the habitat being used from the position of eiders on bathymetric and community maps. The highest density of prey occurred in shallow water reefs where there were patches of blue mussels, Mytilus edulis L., and green sea urchins, Strongylocentrotus droebachienensis (Müller). Despite the fact that eiders can dive to depths as great as 42 m to feed, they strongly aggregate in shallow water, and their distribution closely coincides with the highest density of prey. The degree of selection for the reef habitat varies with seasonal variations in the size of flocks and in the total number of eiders present. Although flocking as an antipredator behaviour cannot be rejected, we interpret the high degree of flocking by eiders in our study area as a strategy to facilitate feeding in winter.

scholarly journals Hybrids of Two Closely Related Tropical Sea Urchins (Genus Echinometra): Evidence Against Postzygotic Isolating Mechanisms

2001 ◽  
Vol 200 (2) ◽  
pp. 97-106 ◽  
Author(s):  
M. Aminur Rahman ◽  
Tsuyoshi Uehara ◽  
John S. Pearse
Keyword(s):  
Sea Urchins ◽  
Isolating Mechanisms ◽  
Tropical Sea
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