Co-existence of two freshwater copepods in lakes through size divergence and diet partitioning.
Bibliographic record
Abstract
We examined the vertical and horizontal distribution patterns of Diaptomus minutus Lilljeborg and Diaptomus oregonensis Forbes in several shallow Quebec lakes where they occurred allopatrically and sympatrically within a small geographic region. Both species overlapped extensively in their vertical and temporal distributions and were found to be positively associated within and among lakes. Although size displacement coul dnot b e detected when body lengths of sympatric and allopatric populations were compared, in lakes where the was a reduction in size overlap between species, the two species co-existed at relatively high densities. This contrasted with situations where convergence in size between species was accompanied by a limited abundance of one or both diaptomids. We conducted stomach-content analyses on the sympatric populations of two of these lakes to determine if diet preference was related to copepod size divergence, an dif algae were selected as a function of copepod size. We found that D. minutus, the smaller copepod, preferentially digested a number of small algal particles (< 10 µm) whereas D. oregonensis, the larger copepod, tended to ingest a greater number of larger particles. Although preference for small algae (Selenastrum and small blue-green algae) was negatiavely correlated with prosome length, preference for larger algal taxa (Planktosphaerium, centric diatoms such as Melosira, and Achnanthes) was positively correlated with diaptomid size. There were, however, differences with respect to the degree of diet overlap between species in the two lakes, which was reflected in a significant negative correlation between dietary and size overlap. These observations are consistent with the hypothesis that reduction in size overlap has resulted in reduced exploitative competition, and that divergence in size and diet may be the mechanism that allows D. minutus and D. oregonensis to co-exist when food becomes limited.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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".