Morphological and molecular evidence for multiple invasions of Codium fragile in Atlantic Canada
Bibliographic record
Abstract
Since the first collection in 1989 from Mahone Bay (Nova Scotia), the highly invasive green macroalga Codium fragile has been spreading in Atlantic Canada and has become established along the coasts of Nova Scotia, Prince Edward Island and New Brunswick. Considerable morphological variation had been found among thalli from different collection sites. This variation may be caused by the presence of different subspecies, or by phenotypic plasticity of one of the subspecies. Morphometric and molecular investigations were performed on Codium collected from seven sites in Maritime Canada and one from Maine to evaluate these hypotheses. Based on both mucron length and ISSR markers, thalli separated into three groups, suggesting multiple introductions of C. fragile into Canada. A group from the eastern shore of Nova Scotia and the coast of New Brunswick is clearly ssp. tomentosoides that likely originates from the United States. A second group, growing in Malpeque Bay in Prince Edward Island, is possibly an asexual variant of ssp. atlanticum , another invasive subspecies of C. fragile . A third group, found in Caribou Harbour only, is an intermediate in terms of both mucron length and molecular data, suggesting a hybrid of ssp. tomentosoides and ssp. atlanticum . The origin of this intermediate group remains to be established.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.002 |
| Science and technology studies | 0.002 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.001 |
| 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".