Formulated feeds prolong the reproductive period of a cultured echinoid
Bibliographic record
Abstract
Abstract Objective The production of echinoid larvae and juveniles is required in both wild-population enhancement programs and full life-cycle culture. Many echinoid species of commercial interest spawn only once or twice a year, however, restricting temporal access to viable broodstock. High-energy/high-protein formulated feeds have been used for gonad enhancement of a variety of echinoid species, but the goal of that activity has always been to produce premature gonads, which the market requires, not the production of mature gonads for breeding. The present investigation, originally established to examine gonad enhancement, took advantage of a spawning event to assess the efficacy of a formulated feed to extend the spawning period or reduce gonad recovery time after spawning in a commercially relevant echinoid, the green sea urchin Strongylocentrous droebachiensis. Methods Urchins held in suspended sea cages were fed either a formulated, commercial, pelleted urchin diet or bull kelp Nereocystis luetkeana over 12 weeks, with survival, somatic growth, gonad quantity (wet weight, yield), and gonad quality (presence/absence of gametes) being examined over time. Result Survivorship after 12 weeks was high, little difference being observed between the two diets (mean ± SE: 98.2 ± 1.1% and 95.9 ± 1.9% for kelp and formulated feed, respectively). There was no significant difference in somatic growth between the two treatments, but the formulated feed led to significantly higher gonad wet weight and yield than kelp at the end of the study. When compared with kelp, the formulated feed may have led to earlier spawning and quicker gonad recovery and prevented the complete spawning of all urchins, thus extending the period of gamete availability. Conclusion Formulated feeds may have the potential to maintain reproductively active broodstock over an extended time, allowing expansion of the period in which echinoid larvae and juveniles can be produced.
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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".