scholarly journals Effect of increased <i>p</i>CO<sub>2</sub> level on early shell development in great scallop (<i>Pecten maximus</i> Lamarck) larvae

2013 ◽  
Vol 10 (10) ◽  
pp. 6161-6184 ◽  
Author(s):  
S. Andersen ◽  
E. S. Grefsrud ◽  
T. Harboe
Keyword(s):  
Marine Invertebrates ◽  
Shell Growth ◽  
Elevated Pco2 ◽  
Pecten Maximus ◽  
Long Term Effects ◽  
Negative Effects ◽  
Pco2 Level ◽  
Larval Stages ◽  
Great Scallop ◽  
Veliger Larvae

Abstract. As a result of high anthropogenic CO2 emissions, the concentration of CO2 in the oceans has increased, causing a decrease in pH, known as ocean acidification (OA). Numerous studies have shown negative effects on marine invertebrates, and also that the early life stages are the most sensitive to OA. We studied the effects of OA on embryos and unfed larvae of the great scallop (Pecten maximus Lamarck), at pCO2 levels of 469 (ambient), 807, 1164, and 1599 μatm until seven days after fertilization. To our knowledge, this is the first study on OA effects on larvae of this species. A drop in pCO2 level the first 12 h was observed in the elevated pCO2 groups due to a discontinuation in water flow to avoid escape of embryos. When the flow was restarted, pCO2 level stabilized and was significantly different between all groups. OA affected both survival and shell growth negatively after seven days. Survival was reduced from 45% in the ambient group to 12% in the highest pCO2 group. Shell length and height were reduced by 8 and 15%, respectively, when pCO2 increased from ambient to 1599 μatm. Development of normal hinges was negatively affected by elevated pCO2 levels in both trochophore larvae after two days and veliger larvae after seven days. After seven days, deformities in the shell hinge were more connected to elevated pCO2 levels than deformities in the shell edge. Embryos stained with calcein showed fluorescence in the newly formed shell area, indicating calcification of the shell at the early trochophore stage between one and two days after fertilization. Our results show that P. maximus embryos and early larvae may be negatively affected by elevated pCO2 levels within the range of what is projected towards year 2250, although the initial drop in pCO2 level may have overestimated the effect of the highest pCO2 levels. Future work should focus on long-term effects on this species from hatching, throughout the larval stages, and further into the juvenile and adult stages.

scholarly journals Effect of increased <i>p</i>CO<sub>2</sub> on early shell development in great scallop (<i>Pecten maximus</i> Lamarck) larvae

2013 ◽  
Vol 10 (2) ◽  
pp. 3281-3310 ◽  
Author(s):  
S. Andersen ◽  
E. S. Grefsrud ◽  
T. Harboe
Keyword(s):  
Marine Invertebrates ◽  
Shell Growth ◽  
Elevated Pco2 ◽  
Pecten Maximus ◽  
Negative Effects ◽  
Co2 Partial Pressure ◽  
Great Scallop ◽  
Egg Number ◽  
Veliger Larvae ◽  
Trochophore Stage

Abstract. As a result of high anthropogenic emission of CO2, partial pressure of carbon dioxide (pCO2) in the oceans has increased causing a drop in pH, known as ocean acidification (OA). Numerous studies have shown negative effects on marine invertebrates, and that the early life stages are the most sensitive to OA. We studied the effects on embryo and larvae of great scallop (Pecten maximus L.), using mean pCO2-levels of 477 (ambient), 821, 1184, and 1627 ppm. OA affected both survival and shell growth negatively after seven days. Growth was reduced with 5–10% when pCO2 increased from ambient 477 ppm to 1627 ppm, and survival based on egg number was reduced from 40.4% in the ambient group to 10.7% in the highest pCO2-group. Larvae/embryos stained with calcein one day after fertilization, showed fluorescence in the newly formed shell area indicating calcification of the shell already at the trochophore stage. Shell hinge deformities were observed at elevated pCO2-levels in trochophore larvae after two days. After seven days, deformities in both shell hinge and shell edge were observed in veliger larvae at elevated pCO2-levels. Although the growth showed a moderate reduction, survival rate and increased amount of deformed larvae indicates that P. Maximus larvae are affected by elevated pCO2 levels within the range of what is projected for the next century.

scholarly journals Sensitivity towards elevated <i>p</i>CO<sub>2</sub> in great scallop (<i>Pecten maximus</i> Lamarck) embryos and fed larvae

2016 ◽  
Author(s):  
Sissel Andersen ◽  
Ellen S. Grefsrud ◽  
Torstein Harboe
Keyword(s):  
Ocean Acidification ◽  
Shell Growth ◽  
Elevated Pco2 ◽  
Pecten Maximus ◽  
Negative Effects ◽  
Great Scallop ◽  
Scallop Larvae ◽  
Negative Effect ◽  
Seawater Carbonate Chemistry

Abstract. The increasing amount of dissolved anthropogenic CO2 has caused a drop in pH-values in the open ocean known as ocean acidification. This change in seawater carbonate chemistry has been shown to have a negative effect on a number of marine organisms. Early life stages are the most vulnerable, and especially the organisms that produce calcified structures in the phylum Mollusca. Few studies have looked at effects on scallops, and this is the first study presented including fed larvae of the great scallop (Pecten maximus) followed until day 14 post-fertilization. Fertilized eggs from unexposed parents were exposed to three levels of pCO2 using four replicate units: 465 (ambient), 768 and 1294 μatm, corresponding to pHNBS of 7.94, 7.74 and 7.54, respectively. All of the observed parameters were negatively affected by elevated pCO2: survival, larval development, shell growth and normal shell development. The latter was observed to be affected only two days after fertilization. Negative effects on the fed larvae at day 7 were similar to what was shown earlier for unfed P. maximus larvae. Growth rate in the group at 768 μatm seemed to decline after day 7, indicating that the ability to overcome the environmental change at moderately elevated pCO2 was lost over time. Food availability may not decrease the sensitivity to elevated pCO2 in scallop larvae. Unless genetic adaptation and acclimatization counteract the negative effects of long term elevated pCO2, populations of scallops may be negatively affected by ocean acidification in the future.

scholarly journals Sensitivity towards elevated <i>p</i>CO<sub>2</sub> in great scallop (<i>Pecten maximus</i> Lamarck) embryos and fed larvae

2017 ◽  
Vol 14 (3) ◽  
pp. 529-539 ◽  
Author(s):  
Sissel Andersen ◽  
Ellen S. Grefsrud ◽  
Torstein Harboe
Keyword(s):  
Shell Growth ◽  
Elevated Pco2 ◽  
Pecten Maximus ◽  
Early Life Stages ◽  
Negative Effects ◽  
Ph Values ◽  
Great Scallop ◽  
Negative Effect ◽  
Seawater Carbonate Chemistry

Abstract. The increasing amount of dissolved anthropogenic CO2 has caused a drop in pH values in the open ocean known as ocean acidification. This change in seawater carbonate chemistry has been shown to have a negative effect on a number of marine organisms. Early life stages are the most vulnerable, and especially the organisms that produce calcified structures in the phylum Mollusca. Few studies have looked at effects on scallops, and this is the first study presented including fed larvae of the great scallop (Pecten maximus) followed until day 14 post-fertilization. Fertilized eggs from unexposed parents were exposed to three levels of pCO2 using four replicate units: 465 (ambient), 768 and 1294 µatm, corresponding to pHNIST of 7.94, 7.75 (−0.19 units) and 7.54 (−0.40 units), respectively. All of the observed parameters were negatively affected by elevated pCO2: survival, larval development, shell growth and normal shell development. The latter was observed to be affected only 2 days after fertilization. Negative effects on the fed larvae at day 7 were similar to what was shown earlier for unfed P. maximus larvae. Growth rate in the group at 768 µatm seemed to decline after day 7, indicating that the ability to overcome the environmental change at moderately elevated pCO2 was lost over time. The present study shows that food availability does not decrease the sensitivity to elevated pCO2 in P. maximus larvae. Unless genetic adaptation and acclimatization counteract the negative effects of long term elevated pCO2, recruitment in populations of P. maximus will most likely be negatively affected by the projected drop of 0.06–0.32 units in pH within year 2100.

scholarly journals Efecto de la temperatura y la acidificación en larvas de Strombus gigas (Mesogastropoda: Strombidae)

2017 ◽  
Vol 65 (2) ◽  
Author(s):  
Jose Francisco Chavez Villegas ◽  
Martha Rosalía Enríquez Díaz ◽  
Dalila Aldana Aranda
Keyword(s):  
Shell Growth ◽  
Ph Control ◽  
Negative Effects ◽  
Final Size ◽  
Raman Analysis ◽  
Strombus Gigas ◽  
Larval Stages ◽  
Hatching Time ◽  
Mortality Ratio ◽  
Experimental Treatments

The increase in CO2 emissions produces heating and reduced pH in the oceans, which may have negative effects on many marine organisms. This is particularly important for those with calcified structures such as the molluscs and their larval stages. We studied Strombus gigas larvae, a gastropod of commercial importance in the Caribbean Sea, in order to know the effect of water temperature and acidification on their development, growth, mortality and calcification during the larval period. A larval culture with triplicate samples was carried out employing four treatments of temperature and pH (Control = 28 °C - pH 8.1, T1 = 28 °C - pH 7.6, T2 = 31 °C - pH 8.1 and T3 = 31 °C - pH 7.6) in August 2015. We registered hatching (No. of eggs – No. of larvae hatched) and organs development, while shell growth and mortality ratio were evaluated over time. Shell calcification was studied in 30 days old larvae using EDX and RAMAN analysis. Our results showed that organs development and shell growth were higher at 31 °C treatments (initial size of 230 ± 4.12 to 313.27 ± 11.34 µm, and final size from 829.50 ± 11.33 to 1 054.50 ± 11.13 µm; from T1 to T2 respectively), and the same pattern was recorded for hatching time (18 hr) and mortality rate (~ 57 %). The Calcium proportion (% wt) was similar between treatments (34.37 ± 10.05 to 37.29 ± 16.81 % wt). Shell Raman analysis showed aragonite in all experimental treatments, with the highest values in the control (1 039.54 ± 780.26 a.u.). Calcite was detected only in 31 °C treatments (174.56 ± 127.19 a.u.), while less intensity of aragonite and calcite were registered at pH 7.6. In conclusion, S. gigas could be adapted to ocean future predictions, however, shell biomineralization processes can be affected.

A scanning electron microscopic study of the veliger larvae of the scallop argopecten purpuratus

1988 ◽  
Vol 46 ◽  
pp. 284-285
Author(s):  
G.C. Bellolio ◽  
K.S. Lohrmann ◽  
E.M. Dupré
Keyword(s):  
Morphological Description ◽  
Electron Microscopic ◽  
Larval Stages ◽  
Scanning Electron Microscopic Study ◽  
The Pacific ◽  
Argopecten Purpuratus ◽  
Veliger Larvae ◽  
20 Nm ◽  
Ethanol Series ◽  
Scanning Electron

Argopecten purpuratus is a scallop distributed in the Pacific coast of Chile and Peru. Although this species is mass cultured in both countries there is no morphological description available of the development of this bivalve except for few characterizations of some larval stages described for culture purposes. In this work veliger larvae (app. 140 pm length) were examined by the scanning electron microscope (SEM) in order to study some aspects of the organogenesis of this species.Veliger larvae were obtained from hatchery cultures, relaxed with a solution of MgCl2 and killed by slow addition of 21 glutaraldehyde (GA) in seawater (SW). They were fixed in 2% GA in calcium free artificial SW (pH 8.3), rinsed 3 times in calcium free SW, and dehydrated in a graded ethanol series. The larvae were critical point dried and mounted on double scotch tape (DST). To permit internal view, some valves were removed by slightly pressing and lifting the tip of a cactus spine wrapped with DST, The samples were coated with 20 nm gold and examined with a JEOL JSM T-300 operated at 15 KV.

Undesirable Effects of Goal Setting on Perceived Fairness, Commitment, and Unethical Behavior

2018 ◽  
Vol 62 (2) ◽  
pp. 97-107 ◽  
Author(s):  
Nina Keith
Keyword(s):  
Goal Setting ◽  
Unethical Behavior ◽  
The United States ◽  
Goal Commitment ◽  
Management Technique ◽  
Long Term Effects ◽  
Perceived Fairness ◽  
Negative Effects ◽  
Positive Effects ◽  
And Performance

Abstract. The positive effects of goal setting on motivation and performance are among the most established findings of industrial–organizational psychology. Accordingly, goal setting is a common management technique. Lately, however, potential negative effects of goal-setting, for example, on unethical behavior, are increasingly being discussed. This research replicates and extends a laboratory experiment conducted in the United States. In one of three goal conditions (do-your-best goals, consistently high goals, increasingly high goals), 101 participants worked on a search task in five rounds. Half of them (transparency yes/no) were informed at the outset about goal development. We did not find the expected effects on unethical behavior but medium-to-large effects on subjective variables: Perceived fairness of goals and goal commitment were least favorable in the increasing-goal condition, particularly in later goal rounds. Results indicate that when designing goal-setting interventions, organizations may consider potential undesirable long-term effects.

scholarly journals Effects of Glyphosate-Based and Derived Products on Sea Urchin Larval Development

2020 ◽  
Vol 8 (9) ◽  
pp. 661
Author(s):  
Davide Asnicar ◽  
Costanza Cappelli ◽  
Ahmad Safuan Sallehuddin ◽  
Nur Atiqah Maznan ◽  
Maria Gabriella Marin
Keyword(s):  
Larval Development ◽  
Sea Urchin ◽  
Marine Invertebrates ◽  
Parent Compound ◽  
Paracentrotus Lividus ◽  
Marine Species ◽  
Negative Effects ◽  
Aminomethylphosphonic Acid ◽  
Main Degradation Product ◽  
Herbicide Glyphosate

Despite the widespread use of herbicide glyphosate in cultivation, its extensive runoff into rivers and to coastal areas, and the persistence of this chemical and its main degradation product (aminomethylphosphonic acid, AMPA) in the environment, there is still little information on the potential negative effects of glyphosate, its commercial formulation Roundup® and AMPA on marine species. This study was conducted with the aim of providing a comparative evaluation of the effects of glyphosate-based and its derived chemicals on the larval development of the sea urchin Paracentrotus lividus, thus providing new data to describe the potential ecotoxicity of these contaminants. In particular, the effects on larval development, growth and metabolism were assessed during 48 h of exposure from the time of egg fertilization. The results confirm that AMPA and its parent compound, glyphosate have similar toxicity, as observed in other marine invertebrates. However, interestingly, the Roundup® formulation seemed to be less toxic than the glyphosate alone.

scholarly journals Larval cryopreservation as new management tool for threatened clam fisheries

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
P. Heres ◽  
J. Troncoso ◽  
E. Paredes
Keyword(s):  
Shell Growth ◽  
Natural Populations ◽  
Ruditapes Philippinarum ◽  
Management Tool ◽  
Equilibration Time ◽  
Ruditapes Decussatus ◽  
Larval Stages ◽  
Long Term Storage ◽  
Declining Species ◽  
Conservation Of Endangered Species

AbstractCryopreservation is the only reliable method for long-term storage of biological material that guarantees genetic stability. This technique can be extremely useful for the conservation of endangered species and restock natural populations for declining species. Many factors have negatively affected the populations of high economical value shellfish in Spain and, as a result, many are declining or threatened nowadays. This study was focused on early-life stages of Venerupis corrugata, Ruditapes decussatus and Ruditapes philippinarum to develop successful protocols to enhance the conservation effort and sustainable shellfishery resources. Firstly, common cryoprotecting agents (CPAs) were tested to select the suitable permeable CPA attending to toxicity. Cryopreservation success using different combinations of CPA solutions, increasing equilibrium times and larval stages was evaluated attending to survival and shell growth at 2 days post-thawing. Older clam development stages were more tolerant to CPA toxicity, being ethylene-glycol (EG) and Propylene-glycol (PG) the least toxic CPAs. CPA solution containing EG yielded the highest post-thawing survival rate and the increase of equilibration time was not beneficial for clam larvae. Cryopreservation of trochophores yielded around 50% survivorship, whereas over 80% of cryopreserved D-larvae were able to recover after thawing.

Proteomic-based comparison between populations of the Great Scallop, Pecten maximus

2014 ◽  
Vol 105 ◽  
pp. 164-173 ◽  
Author(s):  
Sébastien Artigaud ◽  
Romain Lavaud ◽  
Julien Thébault ◽  
Fred Jean ◽  
Øivind Strand ◽  
...  
Keyword(s):  
Pecten Maximus ◽  
Great Scallop
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