The Effect of Sex, Size and Habitat on the Incidence of Puncture Wounds in the Claws of the Porcelain Crab Petrolisthes Cinctipes (Anomura: Porcellanidae)
Bibliographic record
Abstract
Many porcelain crabs have an unusual claw (cheliped) form that is broad, flat and thin. This seemingly flimsy form suggests claws may be used more for display than for feeding or aggressive interactions. However, in the flat-topped porcelain crab Petrolisthes cinctipes, one of the most abundant intertidal crustaceans on the Pacific coast of North America, we observed a high proportion of individuals with puncture wounds on their claws. Claws therefore do appear to be used in intra-specific aggression. To examine factors that might influence injury prevalence, samples of P. cinctipes were collected from four sites in Barkley Sound, two wave-exposed, and two protected. In addition, laboratory experiments examined the effects of density and crab size on the incidence of puncture wounds. Crabs from wave-exposed, high-density sites and smaller crabs both exhibited significantly higher proportions of puncture wounds. Although not statistically significant, laboratory experiments revealed a trend towards a higher incidence of puncture wounds in high-density groups. Wound frequency did not differ between the sexes, so these injuries are not likely a result of intra- or inter-sexual interactions. Puncture wounds were concentrated on claw fingers (either the dactyl or propus), and along the ventral margin of the manus, both of which are likely to be nearest an opponent during shoving interactions. Overall, these data suggest that the claws of P. cinctipes mediate intra-specific competitive interactions that frequently escalate to injury.
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 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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 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) | 0.002 | 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".