Identification of the larval and juvenile stages of the Cubera Snapper, Lutjanus cyanopterus, using DNA barcoding
Bibliographic record
Abstract
The larvae and newly-settled juveniles of the Cubera Snapper, Lutjanus cyanopterus, are identified by DNA barcoding. Four larvae and three small juveniles of L. cyanopterus were detected among a large collection of pelagic larvae and a smaller collection of settled juveniles from the Caribbean coast of Panama. The mtDNA COI barcode sequences from the larvae and juveniles were virtually identical to sequences from adults sampled from the spawning aggregation in St. Thomas, USVI. Barcode sequences for the eleven regional species of Lutjanus species (sensu lato) were obtained and they exhibited deep interspecific divergences that allowed for efficient discrimination among the western Atlantic snapper species. The nearest neighbor species, the Mutton Snapper L. analis, was more than 11% divergent from L. cyanopterus. Cubera Snapper larvae are characterized by prominent melanophores along the outer spinous-dorsal-fin membranes and along the outer third of the longer pelvic-fin membranes. They are morphologically distinct from the late-stage larvae of the other regional snappers by their relatively wider caudal peduncle and their relative dorsal-spine lengths. Juveniles retain the black outer portion of the dorsal and pelvic-fin membranes and have a smaller body-depth than other regional snapper juveniles. The size at settlement is about 18 mm SL, relatively large for lutjanids. Daily otolith increments from L. cyanopterus larvae and juveniles indicate a pelagic larval duration of about 29 days with backcalculated spawning and settlement dates around the new moon. Although smaller adult Cubera Snappers can appear very similar to the Gray Snapper, L. griseus, the larvae and juveniles are quite different. In this case, the early life history stages reflect the deep genetic divergence between the two species while the adult forms converge in appearance.
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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 | 0.000 |
| 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".