Paracentrotus lividus (Echinodermata: Echinoidea) attachment force and burrowing behavior in rocky shores of SW Portugal*

Zoosymposia ◽  
2012 ◽  
Vol 7 (1) ◽  
pp. 231-240 ◽  
Author(s):  
DAVID JACINTO ◽  
TERESA CRUZ

The rock burrowing sea urchin Paracentrotus lividus is a common wave-swept organism that inhabits intertidal rock pools and shallow subtidal temperate shores. Here we present field data on P. lividus attachment force, burrow shape and test diameter measured in different rocky habitats (intertidal pools, low shore intertidal channels and shallow subtidal shores) and in two study sites with different wave-exposure conditions. These data were then analyzed to look for a pos­sible relationship between the size of sea urchins and their attachment force and burrow shape as well as the influence of wave-exposure and habitat in the measured variables. P. lividus test diameter varied among habitats: urchins were smaller in mid-shore intertidal pools and bigger in shallow subtidal shores. We observed in all studied habitats that attachment force was not correlated with test size, while burrow shape index (BSI) was negatively correlated with test size. Results suggest that the attachment force of large and small urchins was similar, but smaller animals occurred in relatively deeper burrows (higher BSI values). Attachment force was positively correlated with BSI, which indicates that burrows may enhance attachment force of P. lividus living in rocky shores by allowing the use of spines as anchorage points and reducing the urchin area exposed to drag forces. Our results partially support the hypothesis that attachment force and BSI might be influenced by local variation in wave-exposure. Higher values for both attachment strength and BSI were measured in intertidal rock pools, the most wave-exposed habitat considered in this study, suggesting that urchins living in such habitat are more able to resist dislodgment by wave-induced forces since they occupy relatively deeper burrows and thusattach more firmly to the substrate. However, neither attachment force nor BSI were higher in the more exposed shore.

Author(s):  
ANGELA SARDO ◽  
RACHELE ROSSI ◽  
VITTORIO SOPRANO ◽  
PATRIZIA CIMINIELLO ◽  
ERNESTO FATTORUSSO ◽  
...  

Blooms of the toxic dinoflagellates Ostreopsis have become common along rocky shores of the Mediterranean Sea. In addition to health problems for beach-goers, Ostreopsis toxins may accumulate in benthic marine animals used for human consumption, which however at times have shown signals of stress and even mortality. In order to elucidate the actual relationships between Ostreopsis and benthic invertebrates, we exposed mussels Mytilus galloprovincialis and sea urchins Paracentrotus lividus from the Gulf of Naples to cultures and natural material of O. cf. ovata and assessed feeding and adverse effects on the animals, along with their acquired toxicity. Mussels exposed to O. cf. ovata for 24 hours filtered the microalgae at different rates, depending on both mussel size and microalgal density, and became weakly toxic in some cases. Under longer exposure most animals died and all survivors were toxic. Detoxification of a naturally toxic mussel populations from an area affected by O. cf. ovata blooms took more than two weeks. Sea urchins fed with the red alga Asparagopsis taxiformis epiphytised by O. cf. ovata did not show damages and became mildly toxic in some cases. However, the direct exposure of sea urchins to O. cf. ovata cultures caused the partial or total loss of the spines in a density-dependent way, with the death of the animals at the highest microalgal concentrations. Milder effects were registered with sonicated cultures or toxin extracts. Our results indicate that the balance between toxicity and animal health in these invertebrates depends on the mode and intensity of exposure to the toxic microalga, while the response varies between the two species but also within the same species. This scenario matches the variety of responses of benthic populations recorded in the natural environment in areas affected by O. cf. ovata blooms.


Author(s):  
Sheanna M. Brady ◽  
Robert E. Scheibling

Repopulation by green sea urchins Strongylocentrotus droebachiensis of a steeply sloping rock bottom was monitored at a wave-exposed headland (Chebucto Head) following a disease outbreak that caused mass mortality in September 1999. Density and size of urchins were sampled in four depth strata: at 8–10 m in an urchin grazing aggregation (front) along the lower margin of a kelp bed, at 12 m and 16 m on a bedrock ramp, and at 24 m on a cobble and boulder field where urchins were unaffected by the disease. Shoreward migration of adults along the ramp from the surviving population at 24 m was the primary means of repopulation, which was augmented by recruitment via planktonic larvae. At 16 m, urchin density stabilized (at ∼50 urchins m−2) within six months of the die-off while repopulation at 12 m took more than eight months. A grazing front of large urchins (40–60 mm, test diameter) had formed along the lower edge of a kelp bed by January 2002, which reached densities of up to 284 urchins m−2. Video surveys at Chebucto Head and two adjacent locations of similar bathymetry revealed an extensive urchin population between 25 and 55 m depth, with a mean density on rocky substrata of 73 urchins m−2.


2021 ◽  
Vol 22 (13) ◽  
pp. 6674
Author(s):  
Luisa Albarano ◽  
Valerio Zupo ◽  
Davide Caramiello ◽  
Maria Toscanesi ◽  
Marco Trifuoggi ◽  
...  

Sediment pollution is a major issue in coastal areas, potentially endangering human health and the marine environments. We investigated the short-term sublethal effects of sediments contaminated with polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) on the sea urchin Paracentrotus lividus for two months. Spiking occurred at concentrations below threshold limit values permitted by the law (TLVPAHs = 900 µg/L, TLVPCBs = 8 µg/L, Legislative Italian Decree 173/2016). A multi-endpoint approach was adopted, considering both adults (mortality, bioaccumulation and gonadal index) and embryos (embryotoxicity, genotoxicity and de novo transcriptome assembly). The slight concentrations of PAHs and PCBs added to the mesocosms were observed to readily compartmentalize in adults, resulting below the detection limits just one week after their addition. Reconstructed sediment and seawater, as negative controls, did not affect sea urchins. PAH- and PCB-spiked mesocosms were observed to impair P. lividus at various endpoints, including bioaccumulation and embryo development (mainly PAHs) and genotoxicity (PAHs and PCBs). In particular, genotoxicity tests revealed that PAHs and PCBs affected the development of P. lividus embryos deriving from exposed adults. Negative effects were also detected by generating a de novo transcriptome assembly and its annotation, as well as by real-time qPCR performed to identify genes differentially expressed in adults exposed to the two contaminants. The effects on sea urchins (both adults and embryos) at background concentrations of PAHs and PCBs below TLV suggest a need for further investigations on the impact of slight concentrations of such contaminants on marine biota.


Author(s):  
Carla Silva ◽  
Marco Lemos ◽  
Rui Gaspar ◽  
Carlos Gonçalves ◽  
João Neto

Biological invasions represent a threat to ecosystems, through competition and habitat destruction, which may result in significant changes of the invaded community. Asparagopsis armata is a red macroalgae (Rodophyta) globally recognized as an invasive species. It is found from the intertidal to shallow subtidal areas, on rock or epiphytic, forming natural vegetation belts on exposed coasts. This study evaluated the variations on native intertidal seaweed and macroinvertebrate assemblages inhabiting rock pools with and without the presence of the invasive macroalgae A. armata. To achieve this, manipulation experiments on Atlantic (Portugal) rock pools were done. Three rock pools were maintained without A. armata by manual removal of macroalgae, and three others were not experimentally manipulated during the study period and A. armata was freely present. In this study the variations between different rock pools were assessed. Results showed different patterns in the macroalgae composition of assemblages but not for the macrobenthic communities. Ellisolandia elongata was the main algal species affected by the invasion of A. armata. Invaded pools tended to show less species richness, showing a more constant and conservative structure, with lower variation of its taxonomic composition than the pools not containing A. armata, where the variability between samples was always higher. Despite the importance of the achieved results, further data based on observation of long-term series are needed, in order to further understand more severe effects of the invader A. armata on native macroalgal assemblage.


2014 ◽  
Vol 15 (3) ◽  
pp. 475 ◽  
Author(s):  
S. GARCIA-SANZ ◽  
P. G. NAVARRO ◽  
F. TUYA

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.


Author(s):  
Iryna Yakovenko ◽  
Asaf Donnyo ◽  
Or Ioscovich ◽  
Benyamin Rosental ◽  
Matan Oren

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.


Dose-Response ◽  
2008 ◽  
Vol 6 (4) ◽  
pp. dose-response.0 ◽  
Author(s):  
Giovanni Pagano ◽  
Giuseppe Castello ◽  
Marialuisa Gallo ◽  
Ilaria Borriello ◽  
Marco Guida

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.


Author(s):  
N.A. Hussain ◽  
E.W. Jones-Knight

Collecting water from rock pools just above rising tides, usually in winter and spring, yielded 1412 Lipophrys pholis, 255 Pholis gunnellus and 29 Coryphoblennius galerita, bearing respectively 172, 8 and 1 Oceanobdella blennii, 744 Taurulus bubalis bearing six Oceanobdella microstoma and 14 Sanguinothus pinnarum, and a Myoxocephalus scorpius with a single O. microstoma; fishes of 23 other species totalled 1243, but none bore leeches externally. Oceanobdella blennii was found mainly in February and March (some in gill chambers), at temperatures generally below 8°C, with lower numbers (all external) in April and May and none later. Infestation was highest in Northumberland. Leeches on P. gunnellus were smaller than those on L. pholis, which they would not attack. They were confined to Northumberland and Scotland, where L. pholis was scarcer. The southern limit of O. blennii seemed to be in north Cornwall, but O. microstoma, though more stenothermal, extends from the Arctic to south Devon, its hosts living mostly subtidally. It is hidden under the chin of Cottidae, whereas S. pinnarum is easily seen on the fins. Abundance in south-west Britain of the ‘cleaner fish’ Crenilabrus melops may explain why S. pinnarum, though common in Scotland and tolerant of summer temperatures, is scarce in Anglesey and not found further south.


2019 ◽  
Vol 70 (7) ◽  
pp. 1045
Author(s):  
Nina Schaefer ◽  
Katherine A. Dafforn ◽  
Emma L. Johnston ◽  
Mariana Mayer-Pinto

Rock pools provide a range of ecological niches that can support diverse assemblages on rocky shores. As intertidal shores are increasingly lost to developments, understanding the drivers of diversity in rock pools is important for the conservation and construction of these key habitats. In this study we investigated relationships between physical characteristics of rock pools and their biota in an urban estuary. We sampled the biota every 6 weeks for 1 year at sites in the inner and outer zones of Sydney Harbour. In the well-flushed and exposed outer zone, sessile and mobile taxa richness was positively related to rock pool width, whereas only mobile taxa richness was related to depth and volume. In the more urbanised and less exposed inner zone, mobile taxa richness was positively related to rock pool width and volume. In both zones, sessile taxa richness decreased with increasing height on shore. Our results suggest that the biodiversity of intertidal rock pools varies depending on their position in Sydney Harbour and the available species pool. Therefore, restoration efforts should consider rock pool size parameters and local environmental conditions, including location, so designs can be optimised to maximise species diversity in these pools.


2002 ◽  
Vol 80 (9) ◽  
pp. 1526-1536
Author(s):  
Lea-Anne Henry

The vertical zonation and temporal dynamics of the marine hydroid Dynamena pumila were assessed across a wave-exposure gradient on five rocky shores in the Bay of Fundy, Atlantic Canada. Hydroid abundance and occupancy (i.e., percentage occurrence in a quadrat) were measured in 0.25-m2 quadrats at eight vertical elevations for each site over four consecutive seasons. Hydroid abundance and occupancy were highly correlated (R2 = 0.877). Estimates of hydroid fertility (percentage of sexually reproductive colonies) and size (stem height and number of branches) were obtained in five quadrats at every elevation over the four seasons. Abundance peaked at about 37.5–62.5% of the mean tidal range, with maximum abundance at the site with moderate wave exposure. Abundance peaked during the summer and dropped dramatically over the winter, particularly at the more wave-exposed sites. Winter ice scour and unfavourable environmental conditions reduced hydroid abundance, fertility, and size during the winter. This study demonstrates dramatic shifts in the distribution, fertility, and size of a marine hydroid. The importance of wave action, ice scour, and seasonal changes in environmental conditions is highlighted to emphasize their roles in regulating intertidal hydroid communities on boreal rocky shores.


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