The structure of the bursa copulatrix in virgin and mated snails, <i>Helisoma duryi</i> (Mollusca): role of acid phosphatase in reproduction
Bibliographic record
Abstract
Abstract. The fine structure of the bursa copulatrix of the virgin snails has been compared with that of mated snails. One of the noticeable changes after mating is an increase in the number of the Golgi and the secretory vesicles. Since some of the vesicles react positively for acid phosphatase it is suggested that this enzyme activity increases following mating. The bursa lumen of the virgin snail contains gel‐like materials devoid of spermatozoa, however, following mating, the lumen is full of semen containing live spermatozoa and bacteria. The source of bacteria in the lumen is not known. Acid phosphatase activity is significantly higher in the luminal content of mated snails than in the virgin snails. The activity is higher in the lumen than in the epithelial cells, suggesting that the enzyme is secreted into the lumen where it is utilized for extracellular degradation of spermatozoa. Following mating, the spermatozoa are motile in the lumen of the bursa for ∼3–7 d, but become immobile and finally undergo extracellular digestion so that intact spermatozoa are not recognizable by day 10. The use of castrated snails in mating experiments suggest that individuals of Helisoma duryi reproduce by cross fertilization and that the bursa may act as the holding organ from where the spermatozoa are periodically transported to the carrefour over ∼7 d. At day 10 following mating, however, autosperms appear in the hermaphroditic duct awaiting the next mating.
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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".