The Importance of the Multicomponent Display in Sexual Selection of Black Morph Girardinus metallicus (Pisces: Poeciliidae)
Bibliographic record
Abstract
Multicomponent displays are composed of traits, such as coloration, structural ornaments, and behavior, that become integrated and signal information to conspecifics. Estimation of multicomponent displays in fishes often involves measurement of color traits. Fish color measurements are often obtained following immobilization via chemical anesthesia; however, the anesthetics may alter the resulting measurements, for example by darkening the skin. Girardinus metallicus, a poeciliid fish endemic to Cuba, has a multicomponent courtship and aggressive display. Black morph males exhibit black ventral coloration including the gonopodium (copulatory organ) and yellow in the non-black areas of their bodies. I investigated the effects of common anesthetics on coloration measurements of G. metallicus. I measured the hue, saturation, and brightness of the anterior dorsal, posterior dorsal, posterior ventral, and caudal body regions, from digital images of the same males obtained without using anesthetic and anesthetized using tricaine methane sulfonate (MS222) and eugenol (clove oil). Because multicomponent displays are intriguing with respect to sexual selection, I investigated the importance of size and coloration traits in sexual selection via female choice and male-male competition in G. metallicus. I found that saturation and hue did not differ significantly across treatments (anesthetization using MS222, anesthetization using clove oil, and without anesthetic in a small glass chamber containing water). However, brightness was greater under the anesthetics, possibly due to photographing the fish behind water and glass in the Non-anesthetic treatment or due to reflectivity differences of the iridophores. The body regions varied in hue, saturation, and brightness. Most importantly, I found differences in the responses of different body regions to the anesthetic treatments, suggesting that anesthetics may affect coloration in unpredictable ways, and that multiple regions of fish should be measured when assessing overall coloration. My results suggest that photographing fish in a glass chamber without anesthetic may be an effective way to obtain digital images for color analysis without using anesthetics that may influence coloration. Having determined a good method for color measurement, I then investigated the role of the multicomponent display in sexual selection. Through direct interaction tests, I found that dominant males had brighter and more saturated yellow coloration than subordinate males, and that dominant males courted more than subordinate males. Within high yellow males, dominant males attempted more copulations than subordinate males. Interestingly, low yellow, subordinate males attempted more copulations than low yellow, dominant males, suggesting that subordinate males invested time into attempting copulations rather than engaging
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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 | 0.000 |
| 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 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".