Species diversity in the new lamprey genus Occidentis, formerly classified as western North American ‘Lampetra’
Bibliographic record
Abstract
Accurate taxonomy is fundamental to the study and conservation of biodiversity. Because of their morphological similarities, most brook and river lampreys in western North America have been placed in the genus Lampetra along with lampreys from Eurasia and eastern North America. However, molecular-based phylogenetic studies dating back several decades indicate that lampreys from Pacific drainages are genetically distinct from Atlantic Lampetra. Reviewing previous phylogenetic analysis of two mitochondrial and two nuclear genes for Northern Hemisphere lampreys, we assign these western North American brook and river lampreys to a new genus, Occidentis. To assess species diversity within Occidentis, we performed a species delimitation analysis using all publicly available cytochrome b sequences of the genus. Similar to previous studies, O. ayresii and O. richardsoni were not reciprocally monophyletic and are best categorized as life history variants of a single species. In addition to O. pacifica, O. hubbsi, and the diverse O. ayresii species complex, as many as seven undescribed candidate species from Oregon and California were identified, supporting results from previous studies with more geographically limited datasets. One specimen from Paynes Creek, California, was identified as a candidate species, although this single individual showed minimal interspecific divergence (1.34%) with O. hubbsi. Further genetic assessment along with information on morphology and phylogeography is needed to determine whether the variation observed between groups of candidate species represents distinct species or divergent lineages within a species complex. Additional sampling will inform whether there are additional species not currently represented in this dataset. Thus, the number of species formally recognized under Occidentis is subject to change with new information. Systematic assessment of the distribution and phylogenetic complexity within Occidentis will enhance our understanding of its evolutionary history and taxonomic diversity, which will guide efforts to conserve the biodiversity of lampreys.
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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 | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| 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".