scholarly journals Chronic arsenate exposure affects amphipod size distribution and reproduction

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8645
Author(s):  
Ioanna Visviki ◽  
Michael L. Judge
Keyword(s):  
Sex Ratio ◽  
Size Distribution ◽  
Test Organism ◽  
Quality Criteria ◽  
Sublethal Concentration ◽  
Water Quality Criteria ◽  
Offspring Sex Ratio ◽  
Leptocheirus Plumulosus ◽  
Chronic Effects ◽  
Inorganic Species

Arsenate (As V) is the predominant inorganic species of arsenic in oxic aquatic environments. Chronic water quality criteria for arsenate have not been established due to the scarcity of relevant studies on its impact on aquatic biota. We examined the acute and chronic effects of arsenate on the benthic amphipod Leptocheirus plumulosus, an important test organism for ecotoxicological studies. We determined that a concentration of 1,971 µg/L arsenate induced 50% mortality (LC50) in juveniles in 96-hr water only exposure. Subsequently, we tested the efficacy of a 42-day sediment bioassay to determine chronic population-level effects. Specifically, we analyzed the survivorship, size distribution, reproduction and offspring sex ratio of this amphipod to a sublethal concentration of arsenate. The sublethal concentration was determined based on the results of the acute tests. Arsenate (500 µg/L) was added to seawater (20 psu) overlying natural sediments (particle sizes < 250 µm). Fifteen replicate chambers per treatment were employed, each stocked with 20 stage-sorted juvenile amphipods (500–600 µm). Five replicates per treatment were destructively sampled on week 3 and ten replicates were sampled on week 6. Arsenate exposure did not affect the survivorship of parental amphipods, as expected, but it decreased significantly the number of offspring in the largest size classes. By week 6, arsenate-exposed replicates had statistically fewer sexually mature offspring compared to controls, likely because the overall reproduction was suppressed. Arsenate exposed amphipods had significantly fewer offspring than controls by week 6 (9.3 vs. 19.1 per parent), but the sex ratio of the offspring was not altered. Our results indicate that size distribution and reproduction may be more sensitive endpoints than survivorship for the chronic effects of arsenate in oxic systems. The extended 42-day bioassay with Leptocheirus plumulosus is a very promising tool to study the effects of toxicants on population dynamics.

scholarly journals Acute and Chronic Effects of Clothianidin, Thiamethoxam and Methomyl on Chironomus dilutus

2021 ◽  
Author(s):  
Bryn M. Phillips ◽  
Jennifer P. Voorhees ◽  
Katie Siegler ◽  
Laura McCalla ◽  
Peter Meertens ◽  
...  
Keyword(s):  
Water Quality ◽  
Emerging Contaminants ◽  
Quality Criteria ◽  
Water Quality Criteria ◽  
Chronic Effects ◽  
Median Lethal Concentrations ◽  
Neonicotinoid Pesticides ◽  
Acute And Chronic Effects ◽  
Carbamate Pesticide ◽  
Chironomus Dilutus

AbstractOrganism tolerance thresholds for emerging contaminants are vital to the development of water quality criteria. Acute (96-h) and chronic (10-day) effects thresholds for neonicotinoid pesticides clothianidin and thiamethoxam, and the carbamate pesticide methomyl were developed for the midge Chironomus dilutus to support criteria development using the UC Davis Method. Median lethal concentrations (LC50s) were calculated for acute and chronic exposures, and the 25% inhibition concentrations (IC25) were calculated for the chronic exposures based on confirmed chemical concentrations. Clothianidin effect concentrations were 4.89 µg/L, 2.11 µg/L and 1.15 µg/L for 96-h LC50, 10-day LC50 and 10-day IC25, respectively. Similarly, thiamethoxam concentrations were 56.4 µg/L, 32.3 µg/L and 19.6 µg/L, and methomyl concentrations were 244 µg/L, 266 µg/L and 92.1 µg/L. Neonicotinoid effect concentrations compared favorably to previously published 96-h and 14-day LC50 concentrations, and methomyl effect concentrations were within the acute survival range reported for Chironomus species and other organisms.

Volume Analysis for Attainability of Water Quality Criteria for Three Loading Constituents

2004 ◽  
Author(s):  
Ping Wang ◽  
Lewis Linker ◽  
James Collier ◽  
Gary Shenk ◽  
Robert Koroncai ◽  
...  
Keyword(s):  
Water Quality ◽  
Quality Criteria ◽  
Water Quality Criteria ◽  
Volume Analysis

Offspring sex ratio in moose Alces alces in relation to paternal age: an experiment

2004 ◽  
Vol 10 (1) ◽  
pp. 51-57 ◽  
Author(s):  
Bernt-Erik Sæther ◽  
Erling J. Solberg ◽  
Morten Heim ◽  
John E. Stacy ◽  
Kjetill S. Jakobsen ◽  
...  
Keyword(s):  
Sex Ratio ◽  
Alces Alces ◽  
Paternal Age ◽  
Offspring Sex Ratio ◽  
Offspring Sex

Cyanide Formation and Fate in Complex Effluents and its Relation to Water Quality Criteria

2015 ◽  
Vol 2 (0) ◽  
pp. 9781780404073-9781780404073
Author(s):  
M. Kavanaugh
Keyword(s):  
Water Quality ◽  
Quality Criteria ◽  
Water Quality Criteria

Developing Ambient Water Quality Criteria for Mercury: A Probabilistic Site-Specific Approach

2015 ◽  
Vol 2 (0) ◽  
pp. 9781780404028-9781780404028
Author(s):  
D. R. J. Moore ◽  
A. Pawlisz ◽  
R. Scott Teed
Keyword(s):  
Water Quality ◽  
Quality Criteria ◽  
Water Quality Criteria ◽  
Ambient Water ◽  
Site Specific ◽  
Specific Approach

Sewage and Solids Disposal: Are Processes Such as Ocean Disposal Proper? The Case of Rio de Janeiro (Brazil)

1990 ◽  
Vol 22 (12) ◽  
pp. 33-43 ◽  
Author(s):  
Eduardo P. Jordão ◽  
Jorge R. Leitão
Keyword(s):  
Environmental Impact ◽  
Rio De Janeiro ◽  
Marine Ecosystem ◽  
Ecological Impact ◽  
Monitoring Program ◽  
Quality Criteria ◽  
Water Quality Criteria ◽  
Federal Regulations ◽  
Concrete Pipe ◽  
Ocean Disposal

In developing countries, as is the case of Brazil, solutions proposed for sewage and sludge treatment and disposal must meet not only public environmental demands and obey proper legal regulations, but also take into account the availability of funds for new investments and operation of existing systems. Brazilian federal regulations allow ocean disposal of sewage and solids, according to certain water quality criteria and specific standards. On the other hand, federal regulations require that submarine outfalls must be studied by means of an Environmental Impact Assessment, and that a Report on the Environmental Impact be produced. Such studies must demonstrate that the site will be protected and that ocean disposal will not impair the environment and the beneficial uses, such as fisihing, recreation, navigation, or propagation of marine life. The State of Rio de Janeiro has monitored its Ipanema Submarine Outfall since 1974, one year prior to going into operation. Present flow is 6m3/sec (140 mgd) of bar-screened domestic sewage. The submarine outfall is a 2.4m diameter concrete pipe, 4.3 km (2.7mi) long, and discharges at a depth of 27m (89ft). The paper presents and discusses existing regulations and data on the seawater monitoring program which is still in practice, having produced more than 90,000 analyses. Discussion covers the period 1974 - 1988, and shows that no adverse ecological impact has been noted on the marine ecosystem.

scholarly journals On the virulence of the entomopathogenic fungi, Beauveria bassiana and Metarhizium anisopliae (Ascomycota: Hypocreales), against the diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae)

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Muhammad Shehzad ◽  
Muhammad Tariq ◽  
Tariq Mukhtar ◽  
Asim Gulzar
Keyword(s):  
Sex Ratio ◽  
Beauveria Bassiana ◽  
Entomopathogenic Fungi ◽  
Plutella Xylostella ◽  
Metarhizium Anisopliae ◽  
Insect Pest ◽  
Diamondback Moth ◽  
Economic Damage ◽  
Offspring Sex Ratio ◽  
Development Of Resistance

Abstract Background The diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), is a noxious pest of cruciferous crops all over the world causing serious economic damage. Management of insect pest generally depends on chemical control; however, due to development of resistance against all types of insecticides, alternative approaches especially utilization of a microbial agent is inevitable. Results Potential of 2 entomopathogenic fungi (EPF), viz., Beauveria bassiana and Metarhizium anisopliae, was evaluated against 2nd and 3rd larval instars of P. xylostella by adopting leaf dip and direct spraying methods under laboratory conditions. Significant mortality rate was achieved by each fungus under adopted methodologies. However, B. bassiana was found to be more effective in both conditions than M. anisopliae. Highest mean corrected mortality (77.80%) was recorded, when spores of B. bassiana were sprayed on the 2nd instar larvae (LC50=1.78×104/ml) after the 6th day of treatment. Similarly, incase of M. anisopliae LC50 for the 2nd instar at the same methodology was 2.78×104/ml with a mortality percentage of 70.0%. Offspring sex ratio was non-significantly related to treatment concentration and methodology, except for the control. Conclusion Beauveria bassiana and M. anisopliae had potential to suppress P. xylostella infestations when applied appropriately. Present findings suggested that B. bassiana and M. anisopliae when sprayed on immatures of host insect had more effect as compared to leaf dip procedure. Furthermore, no significant effect of concentrations was observed on sex ratio.

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