Morphological responses of <i>Daphnia pulex</i> to <i>Chaoborus americanus</i> kairomone in the presence and absence of metals
Bibliographic record
Abstract
Daphnia pulex neonates develop neck teeth in the presence of predatory kairomone from Chaoborus americanus that are fed D. pulex. These neck teeth reduce the susceptibility of the neonates to predation. Evidence suggests that aqueous metals interfere with chemical communication in fish. The objective of our study was to determine if Cu or Ni at environmentally relevant concentrations affects predatory kairomone response in D. pulex. To test this possibility, D. pulex were placed in increasing waterborne concentrations of Cu or Ni in the presence or absence of predatory kairomone. Both Cu and Ni reduced neck tooth induction in D. pulex neonates in the presence of predatory kairomone. Copper had a significant nonlinear effect on neck tooth length consistent with a hormetic response, where neck tooth length was highest at 5 microg/L Cu, but not significantly different than 0 microg/L Cu at higher Cu concentrations. A Ni concentration of 200 microg/L caused D. pulex to become hypersensitive to Chaoborus regardless of Chaoborus' diet, leading to increased neck tooth number but decreased neck tooth length. Neither Ni nor Cu produced any significant effects on body length or brood size. These results suggest that metal inhibition of neck tooth induction probably occurs along the signal transduction pathway. Impairment of chemosensory response to predatory chemical cues may have widespread ecological consequences in aquatic systems contaminated by metals.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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 teacher head, 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".