Low microbial abundance and community diversity in the egg capsule of the oviparous cloudy catshark ( <i>Scyliorhinus torazame</i> ) during oviposition
Bibliographic record
Abstract
Vertebrate embryos are protected from bacterial infection by various maternally derived factors, yet little is known about the defence mechanisms in elasmobranchs. This study aimed to characterize the intracapsular environment of freshly laid eggs of the oviparous catshark (Scyliorhinus torazame) by investigating the microbial abundance and microbiota to understand its potential contribution to embryonic defence. The egg capsule of oviparous elasmobranchs is tightly sealed until pre-hatching, after which seawater flows into the capsule, exposing the embryos to the surrounding seawater. We found that early embryos were highly vulnerable to environmental pathogens, suggesting that the embryos are somehow protected from infection before pre-hatching. Indeed, the intracapsular environment of freshly laid eggs exhibited significantly low bacterial density, maintained until pre-hatching. Furthermore, the microbiome inside eggs just after oviposition differed markedly from those of rearing seawater and adult oviducal gland epithelia; these eggs were predominantly populated by an unidentified genus of Sphingomonadaceae. Overall, this study provides compelling evidence that early embryos of oviparous cloudy catshark are incubated in a clean intracapsular environment that potentially plays a significant role in embryonic development in oviparous elasmobranchs.
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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 | 0.001 | 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 | 0.001 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.002 |
| Research integrity | 0.000 | 0.001 |
| 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".