Genome skimming supports two new crayfish species from the genus Pacifastacus Bott, 1950 (Decapoda: Astacidae)
Bibliographic record
Abstract
Recent phylogenetic analyses have suggested that the Signal Crayfish, Pacifastacus leniusculus (Dana, 1852), contains two highly distinct lineages that merit recognition as species. We further investigate these lineages here using genome skimming to conduct phylogenetic analyses on mitogenomes and highly repetitive 18S, 28S, and H3 nuclear markers. We also analyze morphological characters of these putative species to identify traits that may facilitate their identification in the field. Phylogenetic trees of mitogenomes support these lineages as species in the family Astacidae, and phylogenetic trees based on concatenated nuclear markers return comparable topologies. We describe these crayfishes as the Misfortunate Crayfish, Pacifastacus malheurensis sp. nov., which occurs in central and eastern Oregon, United States, and the Okanagan Crayfish, Pacifastacus okanaganensis sp. nov., which occurs in south central British Columbia, Canada and north central Washington, United States. Both of these species of Pacifastacus face conservation risks from displacement by non-native invasive crayfishes, but P. malheurensis sp. nov. is especially vulnerable to the rapidly spreading Rusty Crayfish, Faxonius rusticus (Girard, 1852), in central Oregon.
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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 | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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".