Distribution of fishes in the Thunder Bay area of northwestern Ontario since deglaciation, with special reference to the darters (Genus Etheostoma) and the Sibley Peninsula
Bibliographic record
Abstract
The prevailing theory explaining fish distribution in the western Lake \nSuperior basin states that recolonization was from south to north following the \nretreating ice margins. Postulated access to post glacial Lake Superior is via \nthe St. Croix River. However, as the ice masses retreated north of Lake \nSuperior, several ice dams held back glacial Lake Agassiz. These were \nsuccessively removed. Lake Agassiz, which covered much of Manitoba and \nnorthwestern Ontario, then catastrophically overflowed into the Superior basin. \nThis allowed fish to gain access to western areas. \nThe Sibley Peninsula and Thunder Bay area provide key evidence for studying \nthe process of fish recolonization. A survey documenting the fishes of Sleeping \nGiant Provincial Park on the Sibley Peninsula allowed comparison of this area \nwith previously surveyed areas (Isle Royale National Park and Quetico Provincial \nPark). The distribution of two darters, the Iowa (Etheostoma exile) and the \njohnny (E. nigrum), suggested that the Thunder Bay area was recolonlzed from both \nthe south and northeast by utilizing Agassiz outlets. \nCreek chub (Semotilus atromaculatus), rock bass {Ambloplites rupestris) \nand common shiner (Notropis cornutus) are found at the edge of their range near \nor in the Kaministiquia basin suggesting either their late movement from the \nsouth into Lake Superior or low colonization powers. Colonization from the south \nis also suggested by johnny darter populations in the Kaministiquia basin. \nGeographic variation among johnny darter populations reveal that the \nKaministiquia basin populations are meristically unique compared to those from \nother nearby areas. Karoinistiquia basin johnny darters are typically the scaly \nform and possess a high number of preoperculomandibular pores. Iowa darter \npopulations do not exhibit much variation in merlstic characters but, similar \nto johnny darters, do exhibit disjunct distribution throughout the Thunder Bay \narea. \nTemperatures selected by Iowa darters during temperature selection trials \nwere always cooler than those selected by johnny darters. Preference for cooler \ntemperatures, along with survival in the Missouri refugium, allowed earlier \nmovement northward following deglaciation. Iowa darters, inhabiting areas \nproximate to early Agassiz overflows, were deposited on both the Sibley Peninsula \nand Isle Royale. \nAnalysis of rivers based on ichthyofaunal resemblance suggests \nKaministiquia basin rivers and those to the south are very similar, likely due \nto similar points of origin for their ichthyofauna. Similarly, ichthyofaunal \nresemblance among Sibley Peninsula rivers suggests a common origin. \nEffects of Isostatic rebound reveals that the Sibley Peninsula contains \nmore species than Isle Royale and the Huron-Porcupine Mountains if basin \nmorphology is taken into account. Lakes on the Sibley Peninsula were elevated \nand Isolated even later than those of Isle Royale. Deep basins on Isle Royale \nallow for the existence of many large openwater species and cold adapted smaller \nspecies which can not inhabit the shallow lakes of the peninsula. \nFishes now inhabiting the Sibley Peninsula and Isle Royale likely arrived \nin those areas during Agassiz discharges. It is suggested that the prevailing \ntheory of the recolonization of the Lake Superior basin must be revised since \nLake Agassiz overflows likely provided a means for fish to move into, rather than \nthrough, the Superior basin.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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 teacher head, 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".