Explaining metal concentrations in sympatric <i>Chironomus</i> species
Bibliographic record
Abstract
We compared metal concentrations in larvae of two Chironomus species (Chironomus staegeri and Chironomustigris) living in the same lake and at the same depth and time. Concentrations of the nonessential metal cadmium (Cd) differed greatly (>8x) between the two species, whereas those of two essential metals differed either much less (zinc [Zn], 2x) or not at all (copper [Cu]). These trends were constant in all seasons. On the one hand, differences in Cd and Zn concentrations between the species were not explained by differences in either their size or their life cycle. Likewise, differential exposure to dissolved metals did not explain larval Cd and Zn concentrations because vertical gradients in dissolved metals did not correlate with depths of larval feeding. On the other hand, the species differed in the type of sediment that they consumed, and measurements of sulfur stable isotopes in larvae confirmed that whereas C. staegeri consumes mostly surface oxic sediment, C. tigris eats mainly deeper anoxic sediment. Because total metal concentrations in gut contents were not correlated with those in larvae, it is likely that metal bioavailability differs between the two sediment types. Overall, our results show that because metal concentrations can differ widely between sympatric congeners, extrapolation from one Chironomus species to another may not be justifiable. Furthermore, because larvae exposed to Zn in the laboratory did not accumulate this metal as they would in the field, we suggest that care is warranted when extrapolating from results obtained in laboratory tests to animals living in the field.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".