90Sr and 137Cs in Arctic echinoderms Saniewski, Michał; Borszcz, Tomasz
Marine pollution bulletin,
11/2017, Letnik:
124, Številka:
1
Journal Article
Recenzirano
Radionuclides in the Arctic echinoderms have seldom been studied despite their considerable environmental importance. This manuscript covers the results of 90Sr and 137Cs measurements in common ...echinoderm taxa collected from the Svalbard Bank in the Barents Sea and from two High-Arctic fjords (Isfjorden and Magdalenefjorden). We focused on the echinoid, Strongylocentrotus droebachiensis, the asteroid, Henricia sanguinolenta, and the ophiuroid, Ophiopolis aculeata. For all echinoderms, the analysis revealed a negative correlation between 90Sr activity and the mass. Thus, we concluded that metals are accumulated faster at a young age when the growth is most rapid. The highest average activities of 137Cs followed the order O. aculeata>H. sanguinolenta>S. droebachiensis. This suggests that bioaccumulation was highly taxon-dependent and could reflect differences in the isotope exposures associated with the diet of echinoderms. The study provides a baseline for understanding radionuclide processes in the High-Arctic benthic echinoderm communities.
•90Sr and 137Cs were investigated in three species of echinoderms from the Arctic.•Activity of 90Sr correlate with dry mass, and thus with animals age/size.•Bioaccumulation of 137Cs was taxon-dependent correlate with trophic levels positions.
Neuropeptides are small molecules that mediate intercellular signaling and regulate physiological processes. Starfish possess various myoactive neuropeptides, including starfish myorelaxant peptide ...(SMP) and a calcitonin-type peptide with apical muscle relaxing properties. In this study, we report the purification of a neuropeptide from starfish (Patiria pectinifera) pyloric caeca extract using high-performance liquid chromatography (HPLC) and an in vitro bioassay to screen for fractions and peptides with relaxing effects on P. pectinifera apical muscle preparations. A series of HPLC steps using reversed-phase and cation-exchange columns yielded a purified peptide with muscle-relaxing effects. The purified peptide's structure was determined by LC-MS and Edman degradation, revealing a pentapeptide with an amidated C-terminus (NGFFYamide) and a molecular mass of 646.2930Da. This is the first report of NGFFYamide purification from P. pectinifera through biochemical methods. The nucleotide sequence encoding the NGFFYamide precursor was determined, showing the presence of a conserved neurophysin domain in the C-terminal region. RT-qPCR results confirmed high expression in radial nerves, consistent with previous findings on NG peptides in echinoderms. In vitro pharmacological studies on muscle preparations from P. pectinifera and Asterias amurensis revealed differential relaxing activity of NGFFYamide on apical muscles, while its effects on tube foot preparations were similar in both species. NGFFYamide also induced potent contraction in P. pectinifera cardiac stomach. Comparison of three NG peptides (NGFFYamide, NGFFFamide, and NGIWYamide) on P. pectinifera cardiac stomach revealed varying potency, suggesting class-specific receptor interactions. Tachyphylaxis was observed in P. pectinifera apical muscle but not in A. amurensis, warranting further investigation. Based on these results, it is plausible that NGFFYamide could be involved in regulating locomotion and feeding behavior in P. pectinifera, consistent with findings in Asterias rubens.
•NG peptides from echinoderms belong to a family of neuropeptides, and are responsible for inducing relaxing and contractile activities.•This study reports the first purification of a neuropeptide (NGFFYamide) from the starfish Patiria pectinifera.•In vitro assay showing NGFFYamide's ability to induce contraction in P. pectinifera tissues related to feeding and digestion suggests that NGFFYamide plays a role in regulating these behaviors.•Consistent RT-qPCR and in vitro activity data suggest NGFFYamide's role in P. pectinifera feeding/digestion.•Unlike A. amurensis' apical muscle, P. pectinifera's showed tachyphylaxis to NGFFYamide, which difference may stem from the variations in size and movement patterns of the two starfish species.
Very little is known about the boring and fouling activities of echinodermsfrom Indian waters. The author. as a result of his studies on Indian echinodermsduring the last 22 years. has collected a ...number of fouling echinodermsbelonging to the classes Crinoidea. Asteroidea. Ophiuroidea. Echinoidea.and Holothuroidea in addition to sea urchins belonging to the families Stomopneustidaeand Echinometridae. which bore into rocks in intertidalregions. These organisms are described.
Structuring over many length scales is a design strategy widely used in Nature to create materials with unique functional properties. We here present a comprehensive analysis of an adult sea urchin ...spine, and in revealing a complex, hierarchical structure, show how Nature fabricates a material which diffracts as a single crystal of calcite and yet fractures as a glassy material. Each spine comprises a highly oriented array of Mg-calcite nanocrystals in which amorphous regions and macromolecules are embedded. It is postulated that this mesocrystalline structure forms via the crystallization of a dense array of amorphous calcium carbonate (ACC) precursor particles. A residual surface layer of ACC and/or macromolecules remains around the nanoparticle units which creates the mesocrystal structure and contributes to the conchoidal fracture behavior. Nature's demonstration of how crystallization of an amorphous precursor phase can create a crystalline material with remarkable properties therefore provides inspiration for a novel approach to the design and synthesis of synthetic composite materials.
A study was conducted to investigate the seasonal diversity of echinoderms along the Palk Bay region of Rameswaram Island. Echinoderm samples were collected weekly throughout 2022, covering ...post-monsoon, summer, pre-monsoon, and monsoon seasons. The sampling took place at the Rameswaram fish landing centre using random collection methods, primarily focusing on specimens obtained as bycatch from trawls. Morphological identification of the specimens was carried out with reference to established literature. A total of 3601 echinoderms belonging to 25 genera, 33 species, and 17 families were recorded across the four seasons. Analysis of seasonal data revealed the highest number of individuals (1121) during the post-monsoon period and the lowest (734) during summer. The most dominant species identified was Salmacis virgulata, accounting for 21.8 % of the occurrences, followed by Salmacis bicolor at 14.3 % respectively.
•A study explored seasonal echinoderm diversity in the Palk Bay region of Rameswaram Island.•A total of 3,601 echinoderms from 25 genera and 33 species were recorded, with Salmacis virgulata being the most dominant.•The study found moderate echinoderm diversity in Rameswaram, Palk Bay region, with a seasonal range of 2.505 to 2.79.•The study strongly recommends banning trawling on seagrass beds in the future to protect echinoderm diversity.
Sea cucumbers and sea urchins are promising candidates for aquaculture since they are high market value and low-trophic organisms. However, although they often co-exist in many marine habitats ...showing feeding interactions, there is currently a lack of investigations available regarding the co-culture of these organisms in Integrated Multi-Trophic Aquaculture (IMTA). The present study investigated, for the first time, the laboratory-scale feasibility of an integrated aquaculture between P. lividus and H. tubulosa, two of the most valuable Mediterranean echinoderms, through a four-month experiment.
More specifically, three food sources with different fish meal concentrations were tested separately to sustain the integrated production in a land-based RAS (Recycling aquaculture system) of both co-cultured species: 1) completely vegetable diet (D-0), 2) vegetable diet with 20% of fish meal (D-20) and 3) vegetable diet with 40% of fish meal (D-40). Among these experimental diets D-20 (with 20% of fish meal supplement) was consumed more efficiently and sustained high growth rates for both co-cultured species. However, significant growth was detected with all experimental diets, indicating successful integrated aquaculture between sea urchins and sea cucumbers. The present study, therefore, suggested the existence of substantial benefits of an integrated aquaculture between these echinoderm species, that could promote the environmental and economic sustainability of their production on a large-scale. Our results showed, in fact, that less than 24% of the organic matter administered with the food remained as waste in our IMTA system after being ingested by the two trophic levels. The sea urchins ingested 87% of the food administered, absorbing 64% of the organic matter, whilst in the second step, the sea cucumbers consumed 54% of organic matter present in the sea urchin feces. Hence the aquaculture model investigated here was highly effective in reducing the total waste, at the same time providing added value in the form of sea cucumber biomass.
•IMTA system combining the sea urchin Paracentrotus lividus, as primary species, and sea cucumber Holothuria tubulosa as extractive species was evaluated for the first time.•Three feeding conditions with different levels of fish meal supplement were evaluated in terms of sea urchin gonad enhancement and somatic growth.•Sea urchin biodeposits, derived from the three experimental diets, were evaluated as the sole food source for the sea cucumbers•The sea cucumber's ability to bio-remediate the sea urchin waste in terms of Absorption Efficiency (AE) and total organic matter leftover was evaluated.
Sea urchins are important components of marine ecosystems and can act as bioindicators, reflecting the health of reefs. The spatial patterns of sea urchins are largely shaped by the type of habitat. ...In Hong Kong, coral communities are divided into two distinct types: reef-building coral habitats and non-reef-building coral habitats. In summer 2020, a qualitative survey was conducted using SCUBA at 56 sites across eastern and western waters, recording a total of 11 species from 6 families of sea urchins. Out of these 56 sites, 14 were selected for a quantitative survey to investigate the relationship between sea urchin assemblages and the two types of coral habitat. We found that the species composition of sea urchins differed significantly between the two habitats, and the presence of sand was a critical factor influencing the species composition of sea urchins. Sand coverage had a positive effect on Salmasic sphaeroides abundance but a negative effect on the abundance of Diadema setosum and Heliocidaris crassispina. The distribution of sea urchins across different degrees of sand coverage may be associated with food availability or species-specific adaptive behaviour, likely due to niche preferences.
•Change in sea urchin species composition from RBC and NRBC habitats.•Sand coverage is an important factor that influences the sea urchin species composition.•The relationship between sea urchins and their habitat is species-specific.
Skeletal Mg/Ca in echinoderms is thought to be related to ambient seawater Mg2+/Ca2+ ratio, which prompts the use of well-preserved fossil echinoderms as paleoseawater Mg2+/Ca2+ proxies. Nonetheless, ...experimental studies testing the effect of seawater Mg2+/Ca2+ ratio on echinoderm skeleton are limited to one echinoderm class, i.e., sea urchins (echinoids). Here, we investigated the effect of decreased seawater Mg2+/Ca2+ ratio on skeletal composition (Mg/Ca ratio) of a sea star Asterias rubens and a brittle star Ophiocomina nigra. Specimens were tagged with manganese and then cultured under three different Mg2+/Ca2+ molar ratios (~5.2, ~2.5, ~1.5 mol/mol) in order to simulate variations of ambient seawater Mg2+/Ca2+ ratio that existed throughout the Phanerozoic. Decreased Mg2+/Ca2+ in seawater did not affect the respiration rates or inhibit calcification of sea stars, which suggests that they were not significantly stressed by the treatment. It did, however, clearly affect growth and mortality in brittle stars, for which reliable geochemical data could not be obtained. Under decreased seawater Mg2+/Ca2+ sea stars produced a skeleton with decreased Mg/Ca ratio. This is consistent with the hypothesis that the skeletal chemistry in echinoderms is influenced by seawater chemistry and, consequently, that fossil echinoderms may preserve a record of paleoseawater Mg2+/Ca2+. Although our data from well-preserved fossil sea stars from the Middle Jurassic and Miocene are consistent with low Mg2+/Ca2+ ratio of the Jurassic "calcite sea" and high Mg2+/Ca2+ ratio of the Miocene "aragonite sea", the accuracy of paleoseawater Mg2+/Ca2+ reconstructions from fossil echinoderms is limited by the fact that Mg partition coefficients vary significantly between different echinoderm species.
The Avilés Canyon System (ACS) is located at the Southern Bay of Biscay (Northern Spain, Cantabrian Sea). The ACS occupies a total of 339.026 ha and is composed of three canyons, reaching the abyssal ...plain at 4700 m depth. Water masses that mix in the area form gyres and upwelling that contribute to increasing the nutrients at different depths, which makes it an important place for the settlement of benthic communities. They have been declared Site of Community Importance (SCI: C ESZZ12003) within the Natura 2000 Network and recognized as a Vulnerable Marine Ecosystem where Echinoderms play an important role in these communities and habitats.
The present study tries to inventory and review asteroid fauna collected during the INDEMARES project in the ACS and compare the new findings with previous studies Official Spanish Checklist (IEEM: “Inventario Español de Especies Marinas”, 2017, 2020) to update our knowledge on the diversity and distribution of the asteroid's species.
During the surveys carried out within the project LIFE + INDEMARES-Avilés Canyon System (2010–2012) a total of 445 specimens, belonging to 25 Asteroids species, were collected from 36 stations in a depth range between 266 and 1476 m. The most frequent species were Nymphaster arenatus (Perrier, 1881) (30.55%) and Henricia caudani (Koehler, 1895) (25%). After public datasets, two species should be considered as new records for Spanish waters: Radiaster tizardi (Sladen, 1882) and Henricia sexradiata (Perrier, 1881), and 4 species expand their bathymetric range: Novodinia pandina (Sladen, 1889), H. caudani, H. sexradiata (Perrier, 1881) and Myxaster perrieri Koehler, 1895.
•New studies about sea-stars from the Aviles Canyon System (Biscay Bay).•A high asteroids richness was found considering the depth range of study.•New record at Spanish North waters R. tizardi.•New alien record at Spanish North waters H. sexradiata from Caribbean Sea.
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