Characterization of lecithotrophic propagules in echinoderms
Bibliographic record
Abstract
Reproduction often involves use of propagules (e.g. spores, seeds and fruit, fertilized eggs, embryos, and larvae), which are frequently dispersed in a medium such as air or water. These propagules possess characteristics (e.g. size, shape, viscosity, biochemical composition) that may influence their viability. Lecithotrophic (maternally-provisioned) eggs of echinoderms display a diversity of colours and buoyancies worldwide, yet these characteristics are rarely investigated in depth. Much more is known on the biochemical composition of propagules in relation to the ecology of lecithotrophic echinoderms. Thus, the objectives of this thesis were to quantify and find trends in the externally observable biophysical properties (colour and buoyancy) and connect them to trends found in the internal biochemical composition (lipids and pigments) across 1) the oocytes of different species of echinoderms with lecithotrophic development (sea stars: Leptasterias polaris, Henricia sanguinolenta, H. perforata, Crossaster papposus, Solaster endeca, sea cucumbers: Cucumaria frondosa and Psolus fabricii) and 2) across stages of oogenesis and development in the sea cucumber C. frondosa. Using an analytical chemistry technique, thin-layer chromatography with ionization detection, chromaticity, and spectrophotometry, I found 1) a trend in most metrics (density, chromaticity colour coordinates, percentages of glyceryl ethers and triacylglycerols, and pigment concentration) of mature oocytes associated with the phylogeny of the seven focal species, and 2) a bell curve trend in all metrics associated with the eco-physiological constraints of each life stage through the ontogeny (early vitellogenic oocytes to early juveniles) of C. frondosa. An additional contribution of this study was the exploration and development of methods to assess the density and colour of the propagules of seven focal species by reappropriating techniques from the fields of analytical chemistry and colour science (chromaticity x,y coordinates). Future research should extend to other invertebrates or externally fertilizing species, and explore the driving effects of visual predators, ultraviolet radiation, and dispersal on propagule characteristics.
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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 | 0.001 | 0.001 |
| 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".