Diets of sexual and sperm‐dependent asexual dace ( <i>Chrosomus</i> spp.): relevance to niche differentiation and mate choice hypotheses for coexistence
Bibliographic record
Abstract
Sperm‐dependent asexual species must coexist with a sexual species (i.e. a sperm source) to reproduce. The maintenance of this coexistence, and hence the persistence of sperm‐dependent asexual species, may depend on ecological niche separation or preference by males for conspecific (i.e. sexual) mates. We first modified an analytical model to consider both of these mechanisms acting simultaneously on the coexistence of the two species. Our model indicates that a small amount of niche separation between parental species and hybrids can facilitate coexistence by weakening the requirement for male mate preference. We also estimated niche separation empirically in the Chrosomus (formerly Phoxinus ) sexual‐asexual system based on diet overlap between sperm‐dependent asexuals and their two sexual host species. Diet overlap between the sexual species was not significant in either lake, whereas the sperm‐dependent asexual had an intermediate niche that overlapped significantly, but somewhat asymmetrically, with both sexual species. These empirical results were then used to parameterize our analytical model to predict the minimum strength of male mate preference required to maintain coexistence in each lake. Some male mate preference is likely required to maintain coexistence in the Chrosomus system, but the minimum required preference depends on the severity of density dependence. Future empirical work on understanding coexistence in sperm‐dependent asexual systems would benefit from taking both niche separation and mate choice into account, and from simultaneous empirical estimates of male mate choice, niche separation, and density dependence.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 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".