Agonistic behaviours and movement in the signal crayfish,<i>Pacifastacus leniusculus</i>: can dominance interactions influence crayfish size-class distributions in streams?
Bibliographic record
Abstract
Size-structured population distributions can result from stage-specific differences in habitat preference or from intraspecific dominance interactions between large and small individuals. The relative importance of these two factors in structuring population distributions was examined in the signal crayfish ( Pacifastacus leniusculus (Dana, 1852)), an organism whose populations are distinctly spatially size-sorted in streams, with adults (A) occupying deeper pools and juveniles (J) inhabiting riffles. In the first of two experiments, groups of crayfish (2A, 2A+2J, or 4J) were released in a constructed riffle–pool–riffle sequence in an experimental channel and individual behaviours and rates of movement were recorded at 2 min intervals. There were differences in habitat preference between the two size classes: adults showed a distinct preference for pools, whereas juveniles did not. In the second experiment, pairs of individuals (A+A, A+J, J+J) were placed in experimental arenas. Analysis of recorded interactions between pairs showed that agonistic interactions and subsequent post-encounter movements were sufficient to produce the exclusion of subordinate individuals from habitats occupied by dominant individuals. These results show that adults have a greater preference for pool habitats than juveniles and that interactions between asymmetrically sized pairs are likely to displace smaller individuals from areas where adult–juvenile encounter rates are high.
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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 | 0.001 |
| 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".