Reproductive Ecology and Captive Breeding of the Threatened Niangua Darter Etheostoma nianguae
Bibliographic record
Abstract
The Niangua darter Etheostoma nianguae is a threatened stream fish endemic to the Osage River basin of Missouri's Ozark uplands. We studied the darter's reproductive behavior under natural conditions in the wild to assist recovery efforts. In addition, techniques for captive propagation were developed in the event that wild populations should suffer precipitous declines. Seven spawning events were witnessed by snorkelers in swift riffle areas at mean (± SD) water depths of 23 ± 5 cm, column current velocities of 83 ± 12 cm/s and focal current velocities of 43 ± 9 cm/s. This combination of depth and velocity was used only for spawning; darters were found at slower velocities and greater depths when not spawning during spring and at slower velocities during summer. Niangua darters in captivity spawned in 38 liter aquaria with fine uniform substrate and no current velocity, and larvae were reared to the juvenile stage. Time from fertilization to hatching was 10–11 d at 16 C. Larvae swam up 3 d after hatching and remained in the water column 31–33 d before returning to the substrate. We suggest a spawning protocol that includes capturing wild males and females during April, isolating spawning pairs in 38 liter aquaria with fine substrate and maintaining low light levels during hatching. Young can be reared on brine shrimp nauplii, zooplankton and, later, frozen adult brine shrimp. A chronology of Niangua darter reproductive and early life history events is provided.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| 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 | 0.002 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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 teacher head, 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".