A method for Rearing Perch, Perca fluviatilis, Larvae Using Paramecium caudatum, Followed by Wild Zooplankton and Formulated Dry Feed in Combination With Adequate Tank Systems
Bibliographic record
Abstract
The present study investigates methods for larviculture and fingerling production in the European perch, Perca fluviatilis. Perch larvae in the stage of first feeding were sensitive to many manipulations necessary in fish culture. Lowering and increasing the tank water level as required for cleaning and water renewal, water flow and aeration led to disturbed buoyancy or mortality in a distinct percentage of larvae. Paramecium caudatum, wild zooplankton containing > 70% copeopds, and formulated dry feed were used for first feeding in combination with flow through tanks or static tanks. For first feeding Paramecium caudatum in combination with a static tank system was optimal resulting in survival rates of circa 90% at 15 days post hatch (dph). Wild zooplankton was no optimal starter feed as perch fed non-selectively on any feed particle available. This resulted in moderate survival rates of circa 50% at 15 dph. First feeding with formulated dry feed caused malformations (enlargement of swimbladders) and a high mortality of > 80%. Weaning from Paramecium caudatum to formulated dry feed and to zooplankton was tested on 8-16 dph larvae. Perch accepted the new food type within 3 days. The optimal time point for zooplankton weaning was 12 dph. In this age larvae had developed a selective feeding behaviour, and fed mainly on nauplii and copepodites. Weaning to formulated dry feed was impossible as larvae developed malformations resulting in high mortality as described above. Weaning from wild zooplankton to formulated dry feed was possible for larvae ≥ 29 dph. No cannibalism was observed in the experiments. The method was also tested in large scale experiments resulting in a survival rate of 65±4%, a total length of 45.0±7.2 mm, and a body weight of 1097±293 mg at 75 dph.
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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) | 0.001 | 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 | 0.001 |
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".