Synonymization of Placobdella picta (Verrill, 1872) (Hirudinea: Glossiphoniidae) with Descriptions of Two New Species Revealed by Molecular Species Delimitation
Bibliographic record
Abstract
Species of Placobdella have been the frequent subject of revisionary and alpha-taxonomy in the past 2 decades. Recent molecular analyses introduced uncertainty about the taxonomic status of several broadly distributed and morphologically variable Placobdella species, including Placobdella picta (Verrill 1872), compounded by incomplete original descriptions reliant upon characters that are no longer unique in comparison to modern congeners. We assessed specimens of P. picta to identify any distinct phylogenetic entities that align with our morphological observations of the type series and novel topotype specimens. Using mitochondrial COI and ND1 and nuclear 18S rDNA with Maximum Likelihood and Bayesian Inference, we evaluated species boundaries using species delimitation analyses (ABGD, mPTP, bPTP, and GMYC) and molecular phylogenetics. Our analyses revealed 2 species entities equivalent to 2 non-reciprocal monophyletic clades. Morphological examinations revealed the lectotype was determined to be Placobdella ornata (Verrill 1872), and paralectotypes are other leech species or were poorly preserved and unidentifiable. Due to the problems with the type series, P. picta is now considered a junior synonym of P. ornata. Based on our results, we describe 2 new species: Placobdella unimaculata n. sp. from Connecticut and Placobdella desseri n. sp. from Algonquin Provincial Park, Ontario, Canada.
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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 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| 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".