PARASITE-INDUCED VARIATION IN HOST MORPHOLOGY: BRAIN-ENCYSTING TREMATODES IN FATHEAD MINNOWS
Bibliographic record
Abstract
Metacercariae of the trematode Ornithodiplostomum ptychocheilus cause a conspicuous enlargement of the cranium of juvenile fathead minnows (Pimephales promelas). Minnows sampled from 2 naturally infected ponds in northern Alberta, Canada, had 12% higher and 7% wider craniums compared to fish from an adjacent, uninfected pond. We tested the prediction that cranial distortion was caused by encystment of metacercariae on the brains of slow-growing minnows in a factorial experiment. Juvenile fish were either exposed once to 120 cercariae or 3 times to 40 cercariae; they were then fed either a low- or high-quantity diet for 8 wk. Results showed that after controlling for host size, cranial heights were affected by infection regime and host diet but not by the infection x diet interaction. Cranial distortion was most prominent in minnows exposed once to cercariae, showing that the rapid, simultaneous growth of metacercariae interfered with the normal development of the cranium. Thus, the expression of the parasite-induced phenotype was context dependent, the result of factors associated with the dynamics of cercariae transmission and host growth rate.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.001 | 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) | 0.001 | 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 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".