Puberty and recrudescence in cultured male yellowtail flounder: plasma androgens and spermatogenesis
Bibliographic record
Abstract
Two year classes of cultured male yellowtail flounder Limanda ferruginea were followed in order to examine puberty and recrudescence at the gonadal level, and to assess the impacts of culture conditions on male reproduction. Cultured males demonstrated a propensity for maturation as 1 year‐old fish. Pubertal activation of testicular steroid production was associated with the appearance of primary spermatocytes, but a single case of a premeiotic endocrine activation was detected. The onset of puberty occurred during September and October, when adults were post‐spawned or in early recrudescence. Once initiated, pubertal development proceeded in an uninterrupted progression to full maturity by June at 22 months of age. Spermatogenetic activity during the autumn led to a peak in the gonado‐somatic index and total testicular mass by December. Milt could be first expressed from some pubertal males at this time, well in advance of the May to August spawning period in captivity. Meiotic activity could be absent from the testes by the spring, but residual areas of meiotic activity were found in pubertal males of one year class which may indicate a slower spermatogenetic rate. Androgen levels peaked during prespawning and early spawning; 11‐ketotestosterone (11‐KT) was the dominant androgen throughout spermatogenesis. Recrudescing 2 year‐old males showed greater testicular development and androgen production. Spermatogenetic patterns were similar to those seen in pubertal males, with the distinction that recrudescing males had a more discernable mitotic phase prior to meiotic activity; mitotic and meiotic activity overlapped considerably during early puberty. Testicular development well in advance of spawning may confer an evolutionary advantage to males of this cold‐water marine flatfish.
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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".