scholarly journals Gökçeada Kıyılarında (Kuzey Ege Denizi) Paracentrotus lividus ve Arbacia lixula Gonadlarında Metal Konsantrasyonları

2021 ◽  
Author(s):  
Melis YILMAZ ◽  
Sezginer TUNCER
Keyword(s):  
Paracentrotus Lividus ◽  
Arbacia Lixula

scholarly journals CHANGES IN THE POTASSIUM CONTENT OF SEA URCHIN EGGS ON FERTILIZATION

1951 ◽  
Vol 34 (3) ◽  
pp. 285-293 ◽  
Author(s):  
Anna Monroy Oddo ◽  
Maria Esposito
Keyword(s):  
Sea Urchin ◽  
Sea Water ◽  
Paracentrotus Lividus ◽  
Potassium Content ◽  
Minimum Point ◽  
Sea Urchin Eggs ◽  
Maximum Loss ◽  
Arbacia Lixula

In the eggs of Arbacia lixula and Paracentrotus lividus an uptake of K occurs during the first 10 minutes following fertilization. Between 10 and 40 minutes K is then released. Both in Arbacia and in Paracentrotus the minimum point of the curve coincides with the nuclear streak stage. A maximum loss of 25 per cent in Arbacia and 20 per cent in Paracentrotus with respect to the amount present in the unfertilized eggs has been found. From 40 minutes up to 1 hour K undergoes a further increase and when the first cleavage sets in the same amount of K is present as in the unfertilized eggs. By treating the eggs with K-free artificial sea water it has been established that about 60 per cent of the K content of the eggs is in a non-diffusible condition. Also under such conditions the eggs when fertilized are able to take up even the very small amount of K present in the medium that was released by them prior to fertilization.

scholarly journals Contrasting recruitment seasonality of sea urchin species in Gran Canaria, Canary Islands (eastern Atlantic)

2014 ◽  
Vol 15 (3) ◽  
pp. 475 ◽  
Author(s):  
S. GARCIA-SANZ ◽  
P. G. NAVARRO ◽  
F. TUYA
Keyword(s):  
Community Structure ◽  
Seasonal Variation ◽  
Sea Urchin ◽  
Sea Urchins ◽  
Late Summer ◽  
Paracentrotus Lividus ◽  
Abundant Species ◽  
Late Winter ◽  
Gran Canaria ◽  
Arbacia Lixula

Despite sea-urchins can play an important role affecting the community structure of subtidal bottoms, factors controlling the dynamics of sea-urchin populations are still poorly understood. We assessed the seasonal variation in recruitment of three sea-urchin species (Diadema africanum, Paracentrotus lividus and Arbacia lixula) at Gran Canaria Island (eastern Atlantic) via monthly deployment of artificial collectors throughout an entire annual cycle on each of four adjacent habitat patches (seagrasses, sandy patches, ‘urchin-grazed’ barrens and macroalgal-dominated beds) within a shallow coastal landscape. Paracentrotus lividus and A. lixula had exclusively one main recruitment peak in late winter-spring. Diadema africanum recruitment was also seasonal, but recruits appeared in late summer-autumn, particularly on ‘urchin-grazed’ barrens with large abundances of adult conspecifics. In conclusion, this study has demonstrated non-overlapping seasonal recruitment patterns of the less abundant species (P. lividus and A. lixula) with the most conspicuous species (D. africanum) in the study area.

scholarly journals Sea urchin response to rising pCO2 shows ocean acidification may fundamentally alter the chemistry of marine skeletons

2014 ◽  
Vol 15 (3) ◽  
pp. 510 ◽  
Author(s):  
L. BRAY ◽  
M.A. PANCUCCI-PAPADOPOULOU ◽  
J. M. HALL-SPENCER
Keyword(s):  
Ocean Acidification ◽  
Species Interactions ◽  
Sea Urchins ◽  
Marine Ecosystem ◽  
Aegean Sea ◽  
Paracentrotus Lividus ◽  
Low Ph ◽  
Reference Sites ◽  
Coastal Systems ◽  
Arbacia Lixula

Ocean acidification caused by an increase in pCO2 is expected to drastically affect marine ecosystem composition, yet there is much uncertainty about the mechanisms through which ecosystems may be affected. Here we studied sea urchins that are common and important grazers in the Mediterranean (Paracentrotus lividus and Arbacia lixula). Our study included a natural CO2 seep plus reference sites in the Aegean Sea off Greece. The distribution of A. lixula was unaffected by the low pH environment, whereas densities of P. lividus were much reduced. There was skeletal degradation in both species living in acidified waters compared to reference sites and remarkable increases in skeletal manganese levels (P. lividus had a 541% increase, A. lixula a 243% increase), presumably due to changes in mineral crystalline structure. Levels of strontium and zinc were also altered. It is not yet known whether such dramatic changes in skeletal chemistry will affect coastal systems but our study reveals a mechanism that may alter inter-species interactions.

scholarly journals Abundance, size composition and benthic assemblages of two Mediterranean echinoids off the Egyptian coasts: Paracentrotus lividus and Arbacia lixula

2015 ◽  
Vol 41 (4) ◽  
pp. 367-374 ◽  
Author(s):  
Elzahrae Elmasry ◽  
Fatma A. Abdel Razek ◽  
Abdel-Fattah M. El-Sayed ◽  
Hamdy Omar ◽  
El Sayed A.E. Hamed
Keyword(s):  
Paracentrotus Lividus ◽  
Size Composition ◽  
Benthic Assemblages ◽  
Arbacia Lixula

Heavy rare earth elements affect early life stages in Paracentrotus lividus and Arbacia lixula sea urchins

2017 ◽  
Vol 154 ◽  
pp. 240-246 ◽  
Author(s):  
Rahime Oral ◽  
Giovanni Pagano ◽  
Antonietta Siciliano ◽  
Maria Gravina ◽  
Anna Palumbo ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Early Life ◽  
Sea Urchins ◽  
Paracentrotus Lividus ◽  
Life Stages ◽  
Early Life Stages ◽  
Heavy Rare Earth ◽  
Heavy Rare Earth Elements ◽  
Arbacia Lixula
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