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 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 Diverse Transformers (Trf) Protein Family in the Sea Urchin Paracentrotus lividus Act through Collaboration between Cellular and Humoral Immune Effector Arms

2021 ◽  
Author(s):  
Iryna Yakovenko ◽  
Asaf Donnyo ◽  
Or Ioscovich ◽  
Benyamin Rosental ◽  
Matan Oren
Keyword(s):  
Sea Urchin ◽  
Sea Urchins ◽  
Paracentrotus Lividus ◽  
Protein Family ◽  
Immune Gene ◽  
Immune Effector ◽  
E Coli ◽  
Purple Sea Urchin ◽  
Humoral Immune ◽  
Extended Families

Sea urchins are long-living invertebrates with a complex immune system which includes extended families of immune receptors. A central immune gene family in the sea urchins encodes for the Transformer (Trf) proteins. The Trf family was so far studied mainly in the purple sea urchin Strongylocentrotus purpuratus. In this study, we explored this protein family in the Mediterranean Sea urchin Paracentrotus lividus. The PlTrf genes and predicted proteins were found to be highly diverse and showed a typical Trf size range and structure. We found that P. lividus coelomocytes and hemolymph contain different PlTrf protein repertoires with a shared subset which specifically bind E. coli bacteria. Using FACS, we identified five different P. lividus coelomocyte sub-populations with cell surface Trf protein expression. The relative abundance of the Trf-positive cells sharply increased following immune challenge with E. coli bacteria, but not following challenge with LPS or sea urchin pathogen V. penaeicida. Finally, we demonstrated that the phagocytosis of E. coli bacteria by P. lividus phagocytes is mediated through the hemolymph and is inhibited by blocking Trf activity with anti-Trf antibodies. Together, our results suggest collaboration between cellular and humoral Trf-mediated effector arms in the P. lividus specific immune response to pathogens.

scholarly journals Complex Mixture-Associated Hormesis and Toxicity: The Case of Leather Tanning Industry

Dose-Response ◽  
2008 ◽  
Vol 6 (4) ◽  
pp. dose-response.0 ◽  
Author(s):  
Giovanni Pagano ◽  
Giuseppe Castello ◽  
Marialuisa Gallo ◽  
Ilaria Borriello ◽  
Marco Guida
Keyword(s):  
Growth Inhibition ◽  
Sea Urchin ◽  
Sea Urchins ◽  
Complex Mixture ◽  
Algal Growth ◽  
Paracentrotus Lividus ◽  
Selenastrum Capricornutum ◽  
Tannery Effluent ◽  
Developmental Defects ◽  
Algal Growth Inhibition

A series of studies investigated the toxicities of tannery-derived complex mixtures, i.e. vegetable tannin (VT) from Acacia sp. or phenol-based synthetic tannin (ST), and wastewater from tannin-based vs. chromium-based tanneries. Toxicity was evaluated by multiple bioassays including developmental defects and loss of fertilization rate in sea urchin embryos and sperm ( Paracentrotus lividus and Sphaerechinus granularis), and algal growth inhibition ( Dunaliella tertiolecta and Selenastrum capricornutum). Both VT and ST water extracts resulted in hormetic effects at concentrations ranging 0.1 to 0.3%, and toxicity at levels ≥1%, both in sea urchin embryo and sperm, and in algal growth bioassays. When comparing tannin-based tannery wastewater (TTW) vs. chromium-based tannery effluent (CTE), a hormesis to toxicity trend was observed for TTW both in terms of developmental and fertilization toxicity in sea urchins, and in algal growth inhibition, with hormetic effects at 0.1 to 0.2% TTW, and toxicity at TTW levels ≥1%. Unlike TTW, CTE showed a monotonic toxicity increase from the lowest tested level (0.1%) and CTE toxicity at higher levels was significantly more severe than TTW-induced toxicity. The results support the view that leather production utilizing tannins might be regarded as a more environmentally friendly procedure than chromium-based tanning process.

Seasonal variation in population and community structure of shrews in a tropical forest of Gabon

2005 ◽  
Vol 21 (2) ◽  
pp. 161-169 ◽  
Author(s):  
Violaine Nicolas ◽  
Patrick Barrière ◽  
Marc Colyn
Keyword(s):  
Community Structure ◽  
Seasonal Variation ◽  
Dominant Species ◽  
Abundant Species ◽  
Dry Season ◽  
Reproductive Phenology ◽  
Ecological Constraints ◽  
Species Dominance ◽  
Composition Structure ◽  
Over Time

The composition, structure and reproductive phenology of a shrew community were investigated for 1 y at two neighbouring sites in an undisturbed African forest of south-western Gabon. We captured 717 shrews, belonging to four genera and 10 species. The data were analysed to answer three main questions: (1) to what extent does the shrew abundance vary seasonally? (2) is there a shift in species dominance over time? and (3) does the intensity of breeding activity vary seasonally? The number of species captured varied seasonally and tended to be least during the period of minimal trap success. Trap success for the four most abundant species (Sylvisorex johnstoni, Crocidura batesi, Paracrocidura schoutedeni and Sylvisorex ollula) varied seasonally with a minimum around the long dry season. Sylvisorex johnstoni remained the dominant species throughout the year. Seasonal variation in trap success of shrews might be related, at least partly, to their reproductive characteristics. Litter size, based on embryo counts, ranged from 1–4 among the species. Breeding occurred throughout the year, but its intensity was lower during the long dry season corresponding with the period of higher ecological constraints for shrews.

scholarly journals The impact of ocean acidification and warming on the skeletal mechanical properties of the sea urchin Paracentrotus lividus from laboratory and field observations

2015 ◽  
Vol 73 (3) ◽  
pp. 727-738 ◽  
Author(s):  
Marie Collard ◽  
Samuel P. S. Rastrick ◽  
Piero Calosi ◽  
Yoann Demolder ◽  
Jean Dille ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Laboratory Experiment ◽  
Young’S Modulus ◽  
Sea Urchin ◽  
Sea Urchins ◽  
Young's Modulus ◽  
Paracentrotus Lividus ◽  
Low Ph ◽  
Fracture Force ◽  
The Impact

Abstract Increased atmospheric CO2 concentration is leading to changes in the carbonate chemistry and the temperature of the ocean. The impact of these processes on marine organisms will depend on their ability to cope with those changes, particularly the maintenance of calcium carbonate structures. Both a laboratory experiment (long-term exposure to decreased pH and increased temperature) and collections of individuals from natural environments characterized by low pH levels (individuals from intertidal pools and around a CO2 seep) were here coupled to comprehensively study the impact of near-future conditions of pH and temperature on the mechanical properties of the skeleton of the euechinoid sea urchin Paracentrotus lividus. To assess skeletal mechanical properties, we characterized the fracture force, Young's modulus, second moment of area, material nanohardness, and specific Young's modulus of sea urchin test plates. None of these parameters were significantly affected by low pH and/or increased temperature in the laboratory experiment and by low pH only in the individuals chronically exposed to lowered pH from the CO2 seeps. In tidal pools, the fracture force was higher and the Young's modulus lower in ambital plates of individuals from the rock pool characterized by the largest pH variations but also a dominance of calcifying algae, which might explain some of the variation. Thus, decreases of pH to levels expected for 2100 did not directly alter the mechanical properties of the test of P. lividus. Since the maintenance of test integrity is a question of survival for sea urchins and since weakened tests would increase the sea urchins' risk of predation, our findings indicate that the decreasing seawater pH and increasing seawater temperature expected for the end of the century should not represent an immediate threat to sea urchins vulnerability.

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 Green Extraction Strategies for Sea Urchin Waste Valorization

2021 ◽  
Vol 8 ◽  
Author(s):  
Stefania Marzorati ◽  
Giordana Martinelli ◽  
Michela Sugni ◽  
Luisella Verotta
Keyword(s):  
Fatty Acids ◽  
Sea Urchin ◽  
Sea Urchins ◽  
Food Resource ◽  
Paracentrotus Lividus ◽  
Added Value ◽  
Physical Parameters ◽  
Widespread Application ◽  
Green Extraction ◽  
Successive Extraction

Commonly known as “purple sea urchin,” Paracentrotus lividus occurs in the Mediterranean Sea and the eastern Atlantic Ocean. This species is a highly appreciated food resource and Italy is the main consumer among the European countries. Gonads are the edible part of the animal but they represent only a small fraction (10–30%) of the entire sea urchin mass, therefore, the majority ends up as waste. Recently, an innovative methodology was successfully developed to obtain high-value collagen from sea urchin by-products to be used for tissue engineering. However, tissues used for the collagen extraction are still a small portion of the sea urchin waste (<20%) and the remaining part, mainly the carbonate-rich test and spines, are discarded. Residual cell tissues, tests, and spines contain polyunsaturated fatty acids, carotenoids, and a class of small polyphenols, called polyhydroxynaphthoquinones (PHNQ). PHNQ, due to their polyhydroxylated quinonoid nature, show remarkable pharmacologic effects, and have high economic significance and widespread application in several cosmetic and pharmaceuticals applications. A green extraction strategy aimed to obtain compounds of interest from the wastes of sea urchins was developed. The core strategy was the supercritical CO2 technique, characterized by low environmental impacts. Fatty acids and carotenoids were successfully and selectively extracted and identified depending on the physical parameters of the supercritical CO2 extraction. Finally, the exhausted powder was extracted by solvent-based procedures to yield PHNQ. The presence of Spinochrome A and Spinochrome B was confirmed and extracts were characterized by a remarkably high antioxidant activity, measured through the 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assay. Overall, the selective and successive extraction methods were validated for the valorization of waste from sea urchins, demonstrating the feasibility of the techniques targeting added-value compounds.

scholarly journals Sibling Bald Sea Urchin Disease affecting the edible Paracentrotus lividus (Echinodermata: Echinoidea) in Sardinia, Italy

2019 ◽  
Author(s):  
Daniele Grech ◽  
Ivan Guala ◽  
Simone Farina
Keyword(s):  
Mediterranean Sea ◽  
Infection Rate ◽  
Sea Urchin ◽  
Environmental Changes ◽  
Sea Urchins ◽  
Paracentrotus Lividus ◽  
Pathogen Transmission ◽  
Microbiological Analysis ◽  
Genetic Population ◽  
Sampling Campaign

Different species of echinoids and bivalves are suffering infectious diseases as the effect of ocean warming. In Sardinia (Western Mediterranean Sea) the keystone sea urchin species Paracentrotus lividus (Lamarck 1816) is widely appreciated as edible resource. Recently, a number of individuals were found to be infected by a no specified bacterial morphologically matching to a “bald sea urchin disease” (Fig. 1). In February 2019, a sampling campaign took place in two locations in the West and East Coast, inside and in proximity of local Marine Protected Areas. Field samplings were approved by the Regione Autonoma Sardegna (Fishing License for scientific purposes n.310/AP SCIE/N.1 10/01/2019). Samplings were carried out at the end of February 2019, when water temperature was 13°C. For each sampled site we performed two replicates of fast 50 m belt transects to estimate the infection rate as the total individuals infected on the total counted. The estimated infection rate was around 5% in both of sampled locations. A higher level of preyed sea urchins was observed, compared to natural predatory level previously observed in all the surveyed sites. Moreover, an unusual amount of dead sea urchins has been observed stranded on the storm berm, neighbouring one of the sampled sites. Microbiological analysis puts in evidence bacterial infection as the potential causal agent that could be temperature-related. Previous mass mortalities of sea urchins due to this infection were reported in the northwestern Mediterranean Sea in the past, where populations of shallow waters sharply declined until 75% during the summer period. A number of papers argued global warming might be linked to the occurrence of catastrophic events in the Mediterranean Sea, which could alter the host/pathogen range and modify pathogen transmission rates. Thus, the spread of the infection could cause important consequences at genetic, population, community and ecosystem level. In the study area, it seems already evident how predatory pressure on populations sampled was increased probably due to the lowering of the natural defences of the sea urchin preys as consequence of the infection. Accordingly, the outbreak of this infection probably related with environmental changes could determine important effects on trophic interactions and generating unpredictable cascading effects. In this area, an increasing of the sea urchin disease and related mortality is expected in the next months with the temperature increasing. A long-term monitoring across the summer season will be crucial to understand the extent and magnitude of the phenomenon as its implications.

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