Functional morphology of sexually selected gentalia in the water strider <i>Aquarius remigis</i>
Bibliographic record
Abstract
In the water strider Aquarius remigis (Say), sexual selection favours males with longer genitalia. We used video analysis plus light and scanning electron microscopy to examine the structure, movement, and articulation of the genitalia as a first step in determining the functional basis of this selection. Male A. remigis are characterized by long, robust genital segments; a marked ventral median notch in the posterior margin of the pregenital segment; an enlarged phallus tipped with a uniquely prolonged sclerotized plate; and a large, spine-covered, membranous lobe that inflates within the female's reproductive tract. Detailed examinations of genital interactions prior to and during copulation allow us to deduce the functional significance of these distinguishing traits. We postulate that by increasing the length, mobility, strength, and rigidity of the phallus, the first three traits increase the ability of males to achieve intromission in spite of active female resistance, and to maintain intromission during the prolonged copulations characteristic of this species. Inflation of the large, spinous lobe probably contributes to the latter function, and may also directly affect fertilization success by displacing or damaging sperm from previous males. We discuss these interpretations in the context of current theories of genitalic coevolution and sexual conflict in the Gerridae.
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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 | 0.001 | 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".