Mexorchestia: a new genus of talitrid amphipod (Crustacea, Amphipoda, Talitridae) from the Gulf of Mexico and Caribbean Sea, with the description of a new species and two new subspecies
Bibliographic record
Abstract
Two species of supralittoral Tethorchestia were reported by Bousfield (1984) to occur on the shores of the Gulf of Mexico and closely adjacent waters: T. antillensis Bousfield, 1984 from Quintana Roo, Mexico and an undescribed species, Tethorchestia sp. B of Bousfield (1984), from Florida and the U.S. Gulf coast. In this paper, we rediagnose and illustrate the former taxon based on material from Goodland Bay, Florida, which represents a range extension for that species. We examined the latter taxon from many locations throughout the Gulf of Mexico using classical morphology, epidermal pigment pattern recognition and allometry, reinforced by molecular markers (mitochondrial cytochrome oxidase I, Radulovici 2012), determining that Tethorchestia sp. B represents a new genus and species, comprising two subspecies. The nominate subspecies, Mexorchestia carpenteri carpenteri n. gen., sp. and subsp., is described from Tiger Tail Beach, Florida, based on conventional morphological criteria and its distinctive epidermal pigment patterns. The Tiger Tail Beach ecotope of M. c. carpenteri n. gen., sp. and subsp. was distinct from that of other locations examined in Florida and was associated with epidermal pigment pattern polymorphism, absent at other locations. A second subspecies, distinguished by differences in size, number of articles in the flagellum of antenna 2, the number of marginal setae on oostegite 2 of the female and the number of distal dorsolateral robust setae on the telson, was found in samples from Belize and Mexico. This subspecies is described from material collected at Turneffe Island, Belize, as Mexorchestia carpenteri raduloviciae n. gen., sp. and subsp. Like M. c. carpenteri n. gen., sp. and subsp., this taxon is also associated with epidermal pigment pattern polymorphism. A key is provided for the three currently described species of Tethorchestia (two extant) and two new subspecies of Mexorchestia n.gen.
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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 | 0.001 | 0.000 |
| 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".