Sexual dimorphism in pelvic fin length of Atlantic cod
Bibliographic record
Abstract
Behavioural differences between females and males may result in sexual dimorphism among morphological traits associated with these behaviours. In the broadcast-spawning Atlantic cod ( Gadus morhua L., 1758), release of gametes occurs during a “ventral mount” in which the male positions himself directly beneath the female while grasping her with his pelvic fins. Males also display the pelvic fins during agonistic encounters with other males. Based on data obtained from four Atlantic cod populations off Canada and Norway, we find clear evidence of sexual dimorphism in pelvic fin size, the fins being significantly larger in males than in females. Pelvic fin size was, however, not more variable than other morphological traits and was not correlated with body condition or drumming muscles mass (hypothesized to be a secondary sexual characteristic in this species). To our knowledge, this is the first study to demonstrate sexual dimorphism in any external morphological trait in a gadoid fish. Although the observed differences in pelvic fin size may be a product of sexual selection, we identify future work to test this hypothesis and to explore more fully the causes and fitness consequences of this sexual bias in Atlantic cod.
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 | 0.000 | 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 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".