Glandular quinoline-derivates protect crustacean woodlice from spider predation
Bibliographic record
Abstract
In evolutionary time, aquatic crustaceans colonized land and faced new terrestrial predators such as spiders and ants. We tested the hypothesis that the crustacean terrestrial woodlouse Porcellio scaber produces defensive metabolites that provide protection against terrestrial predators. When attacked by a predator, P. scaber expels proteinaceous secretions from its tegumental glands. Analyses of gland secretion extracts by gas chromatography–mass spectrometry and by liquid chromatography–mass spectrometry revealed four metabolites: methyl 8-hydroxy-quinoline-2-carboxylate, methyl 8-hydroxy-4-methoxy-quinoline-2-carboxylate, methyl 8-(sulfooxy)quinoline-2-carboxylate and methyl 4-methoxy-8-(sulfooxy)quinoline-2-carboxylate, the latter three being natural products not previously known. In behavioural experiments, Steatoda grossa spiders readily preyed on Tenebrio molitor beetles but avoided chemically well-defended P. scaber . When beetles were rendered chemically well-defended by topical applications of either P. scaber gland secretion extract or synthetic metabolites identified in these extracts, spiders rejected the beetles as prey. Our data support the hypothesis that P. scaber produces defensive metabolites against terrestrial predators. We show that the crustacean P. scaber , like many insects, is chemically defended against predators.
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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 | 0.000 |
| 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".