Lipofuscin Quantification as a Potential Tool for Age Estimation in Snow Crabs,Chionoecetes opilio (O. Fabricius, 1788) (Decapoda, Oregoniidae)
Bibliographic record
Abstract
Abstract Lipofuscin levels were investigated in snow crabs (Chionoecetes opilio) to assess the applicability of lipofuscin quantification as an age determining tool for this species. Localization and quantification of lipofuscin granules in the olfactory lobe cell mass (OLCM) of the brain were conducted by confocal microscopy and image analysis. The majority of immature crabs had no detectable lipofuscin. Crabs with a dirty carapace condition (an indication of greater age) had more lipofuscin (in terms of granule density, area fraction, and mean granule size) than crabs with a clean carapace condition; however, the amount of lipofuscin was much lower than that in more temperate species. Lipofuscin content was positively correlated with carapace size among crabs with a clean carapace but not among crabs with a dirty carapace. No correlation was observed between average lipofuscin granule fluorescent intensity and carapace width. OLCM neuron characteristics were also investigated. An inverse relationship was observed between neuron density and carapace width although it is unknown if this density reduction is due to a loss of neurons, an increase in size of the structures, or both. Furthermore, a positive relationship was observed between neuron size and carapace width. The range of neuron size also increased in larger crabs, suggesting the presence of mitotically active cells in the OLCM. Although lipofuscin levels were higher in dirty carapace condition (presumably older) crabs than in clean carapace crabs and increased with size (in mature, clean carapace snow crabs), the lack of detectable lipofuscin in most immature crabs, generally low levels of lipofuscin in mature crabs, and lack of increase with size in older (dirty carapace) crabs limits the applicability of this age estimation tool for this species.
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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 | 0.002 | 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".