Use of the freshwater macroinvertebrate Chironomus riparius (diptera: chironomidae) in the assessment of sediment toxicity

1996 ◽  
Vol 34 (7-8) ◽  
pp. 101-107 ◽  
Author(s):  
M. M. Watts ◽  
D. Pascoe
Keyword(s):  
Sediment Toxicity ◽  
Larval Growth ◽  
Sediment Contamination ◽  
Chironomus Riparius ◽  
Lower Percentage ◽  
Life Stages ◽  
Significant Growth ◽  
Polluted Sediment ◽  
Polluted Sites ◽  
Reference Sediment

The growth and emergence responses of the midge Chironomus riparius Meigen were used to evaluate the toxicity of natural and formulated reference sediments which were either obtained from polluted sites or spiked with copper in the laboratory. A significant reduction in larval growth was only observed in one of the two polluted field sediments tested. The reasons for this are discussed. However, copper spiking resulted in significant growth reductions of larvae exposed to the two formulated reference sediments at copper concentrations of 3 and 4 mg Cu2+ 1−1. Growth of larvae exposed in natural reference sediment was not significantly affected at equivalent concentrations. The emergence of adults was adversely affected in polluted field sediment compared to formulated reference sediment. Male, female and total adult median emergence times (EmT50) were significantly greater in the former treatment indicating a delay in emergence, attributable to sediment contamination. In addition, survivorship of the larvae in the polluted sediment was reduced, resulting in a lower percentage of adults emerging compared to the formulated reference sediment. The results of this study illustrate the usefulness of chronic response criteria, incorporating the more sensitive life-stages of C. riparius, in the assessment of sediment toxicity.

scholarly journals Ecotoxicological assessment of sediments from the Santos and São Vicente estuarine system- Brazil

2006 ◽  
Vol 54 (1) ◽  
pp. 55-63 ◽  
Author(s):  
Augusto Cesar ◽  
Camilo Dias Seabra Pereira ◽  
Aldo Ramos Santos ◽  
Denis Moledo de Sousa Abessa ◽  
Nuria Fernández ◽  
...  
Keyword(s):  
Sediment Toxicity ◽  
Principal Component ◽  
Sediment Contamination ◽  
Estuarine Sediments ◽  
Toxicity Tests ◽  
Estuarine System ◽  
Chemical Analyses ◽  
Sediment Toxicity Tests ◽  
Close Relationship ◽  
Aquatic Food

Sediments represent an important repository of pollutants and a source of contamination for the aquatic food web. Toxicity tests using amphipods as test-organisms have been employed in the assessment of marine and estuarine sediments, together with chemical analyses. The present work aimed to evaluate the quality of sediments from six stations situated in the Santos and São Vicente Estuarine and Harbour System (São Paulo - Brazil) using acute whole sediment toxicity tests with amphipods (Tiburonella viscana) and chemical analyses of metals, PCB's, and PAH's. Other sediment parameters, such as organic carbon and grain size distribution were also analysed. Higher contamination levels were observed in the internal portion of the estuary, where Santos harbour and the industrial zone are located. The toxicity tests showed significant adverse results for most of the samples tested, and the sediments from the internal portion of the estuary presented the highest toxicity. The principal component analyses (PCA) indicated a close relationship between sediment contamination and toxicity. Positive correlation of these factors in the samples studied was used to establish the ranges of the chemical concentrations associated with adverse effects. Such ranges allowed the estimation of preliminary effect threshold values for sediment contamination, by means of multivariate analysis. These suggested values are: Cu, 69.0; Pb, 17.4; Zn, 73.3 (mg.kg-1); PAHs, 0.5 (mg.kg-1) and PCBs, 0.1 (µg.kg-1).

Interactions between food quantity and quality (long-chain polyunsaturated fatty acid concentrations) effects on growth and development of Chironomus riparius

2007 ◽  
Vol 64 (3) ◽  
pp. 425-436 ◽  
Author(s):  
Willem Goedkoop ◽  
Marnie Demandt ◽  
Gunnel Ahlgren
Keyword(s):  
Arachidonic Acid ◽  
Fatty Acid ◽  
Scenedesmus Obliquus ◽  
Larval Growth ◽  
Somatic Growth ◽  
Chironomus Riparius ◽  
Food Sources ◽  
Chain Polyunsaturated Fatty Acid ◽  
Adult Size ◽  
Food Quantity

We quantified somatic growth, development, and emergence of the midge Chironomus riparius on experimental diets (oats, Spirulina, and Tetraphyll®) covering gradients in food quality (differing polyunsaturated fatty acids) and quantity (0.1–5.4 mg C·day–1). Additionally, similar incubations without food additions were made using a food-poor sediment containing peat and the green alga Scenedesmus obliquus. Larval and adult size was affected by both food quantity and quality and increased some three to four times across the food concentration gradients. Adult emergence, however, was affected only by food quantity. A type 3 response model showed that a saturation level was reached for the oats treatment at 2.7 mg C·day–1 (or 3.9 µg ω3 and 120 µg ω6 polyunsaturated fatty acids·day–1), indicating that the quality of oats constrained further stimulation of larval growth. In the peat treatment, larval growth was very low, no adults emerged, and no larvae even made it to the pupa stage. Fatty acid analyses showed that larvae were capable of synthesizing arachidonic acid via γ-linolenic acid by Δ6- and Δ5-desaturase activity using linoleic acid available in food sources. This strongly suggests that C. riparius is not dependent on dietary sources of eicosapentaenoic acid and arachidonic acid and can sustain viable populations even under a low-quality food regimen.

scholarly journals Combined effects of low pH and low oxygen on the early-life stages of the barnacle Balanus amphitrite

2015 ◽  
Vol 73 (3) ◽  
pp. 791-802 ◽  
Author(s):  
Camilla Campanati ◽  
Stella Yip ◽  
Ackley Lane ◽  
Vengatesen Thiyagarajan
Keyword(s):  
Early Life ◽  
Interactive Effect ◽  
Low Ph ◽  
Limiting Factors ◽  
Lower Percentage ◽  
Life Stages ◽  
Balanus Amphitrite ◽  
Early Life Stages ◽  
Low Oxygen ◽  
Extreme Stress

Abstract Ocean acidification (OA) is anticipated to interact with the more frequently occurring hypoxic conditions in shallow coastal environments. These could exert extreme stress on the barnacle-dominated fouling communities. However, the interactive effect of these two emerging stressors on early-life stages of fouling organisms remains poorly studied. We investigated both the independent and interactive effect of low pH (7.6 vs. ambient 8.2) and low oxygen (LO; 3 mg l−1 vs. ambient 5 mg l−1) from larval development through settlement (attachment and metamorphosis) and juvenile growth of the widespread fouling barnacle, Balanus amphitrite. In particular, we focused on the critical transition between planktonic and benthic phases to examine potential limiting factors (i.e. larval energy storage and the ability to perceive cues) that may restrain barnacle recruitment under the interactive stressors. LO significantly slowed naupliar development, while the interaction with low pH (LO–LP) seemed to alleviate the negative effect. However, 20–50% of the larvae became cyprid within 4 d post-hatching, regardless of treatment. Under the two stressors interaction (LO–LP), the barnacle larvae increased their feeding rate, which may explain why their energy reserves at competency were not different from any other treatment. In the absence of a settlement-inducing cue, a significantly lower percentage of cyprids (∼15% lower) settled in LO and LO–LP. The presence of an inducing cue, however, elevated attachment up to 50–70% equally across all treatments. Post-metamorphic growth was not altered, although the condition index was different between LO and LO–LP treatments, potentially indicating that less and/or weaker calcified structures were developed when the two stressors were experienced simultaneously. LO was the major driver for the responses observed and its interaction with low pH should be considered in future studies to avoid underestimating the sensitivity of biofouling species to OA and associated climate change stressors.

scholarly journals Variation in Expression of Reference Genes across Life Stages of a Bee, Megachile rotundata

Insects ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 36
Author(s):  
Junhuan Xu ◽  
Dennis L. Welker ◽  
Rosalind R. James
Keyword(s):  
Honey Bees ◽  
Reference Genes ◽  
Larval Growth ◽  
Environmental Toxins ◽  
Western United States ◽  
Life Stages ◽  
Megachile Rotundata ◽  
Alfalfa Seed ◽  
Transcription Data ◽  
Transcriptomic Studies

The alfalfa leafcutting bee, Megachile rotundata is widely used in the western United States as a pollinator for alfalfa seed production. Unfortunately, immatures experience high mortality in agriculturally managed populations. Quantified gene expression could be used to identify how this bee responds during different life stages to pathogens, environmental toxins, and other stresses, but stably expressed reference genes are needed to normalize transcription data. We evaluated twelve candidate genes for their transcription stability across different life stages, including during and after diapause. RPS18 and RPL8 were the two most stably expressed genes, followed by RPS5 and RPL27A. These genes were also very stable even during and after diapause, while the most variable genes being APN, PMIIM, NPC2, and Cr-PII had increased expression levels during larval growth and were also variable during and after diapause. The four reference genes we identified in M. rotundata may prove useful for transcriptomic studies in other bees as well, such as honey bees.

Testing lagoonal sediments with early life stages of the copepod Acartia tonsa (Dana): An approach to assess sediment toxicity in the Venice Lagoon

2018 ◽  
Vol 147 ◽  
pp. 217-227 ◽  
Author(s):  
Marco Picone ◽  
Martina Bergamin ◽  
Eugenia Delaney ◽  
Annamaria Volpi Ghirardini ◽  
Kresten Ole Kusk
Keyword(s):  
Early Life ◽  
Sediment Toxicity ◽  
Venice Lagoon ◽  
Acartia Tonsa ◽  
Life Stages ◽  
Early Life Stages

In situ Bioassays with Chironomus riparius : Laboratory-Field Comparisons of Sediment Toxicity and Effects During Wintering

2003 ◽  
Vol 6 (2) ◽  
pp. 217-228 ◽  
Author(s):  
P. J. den Besten ◽  
A. Naber ◽  
E. M. M. Grootelaar ◽  
C. van de Guchte
Keyword(s):  
Sediment Toxicity ◽  
Chironomus Riparius ◽  
In Situ Bioassays
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