Trophodynamics of <i>Protomyctophum</i> (Myctophidae) in the Scotia Sea (Southern Ocean)
Bibliographic record
Abstract
This study investigated spatial and temporal patterns in distribution, population structure and diet of Bolin's lanternfish Protomyctophum bolini, Tenison's lanternfish Protomyctophum tenisoni and gaptooth lanternfish Protomyctophum choriodon in the Scotia Sea using data collected by midwater trawl during spring, summer and autumn. Protomyctophum bolini was the most abundant species of the genus encountered throughout the Scotia Sea with the greatest concentrations occurring around the Antarctic Polar Front (APF). This species had a life cycle of 2+ years, but spatial differences in population structure were apparent as the I-group was absent from all regions south of the APF, suggesting that the species does not recruit in the Scotia Sea. Protomyctophum tenisoni occurred mostly in waters characteristic of the APF and was absent from the southern Scotia Sea. It had a limited size range, but there was clear size-related sexual dimorphism with males significantly larger than females. The species had a life cycle of c. 2 years, but the I-group (c. 1 year old, 1 November to 31 October the next year) occurred only in regions close to the APF suggesting that recruitment is restricted to these waters. A seasonal southward migration for P. choriodon is likely as the species occurred mostly to the south-west of South Georgia in summer, but extended to the sea-ice sectors in autumn. Protomyctophum choriodon had a life cycle of 4+ years in the Scotia Sea and the population was dominated by age classes >3 years old. Larval stages were absent during the surveys for all species. Diurnal variations in vertical distribution were apparent for all three species. Interspecific variations in diet were evident, but all species were primarily copepod feeders, with Metridia spp., Rhincalanus gigas and Calanus simillimus generally dominating their diet. Small euphausiids, principally Thysanoessa spp., were also an important component of their diets, particularly for P. choriodon which had the largest body size. The spatial and temporal variations in diet for both P. bolini and P. tenisoni were broadly consistent with underlying abundance patterns within the mesozooplankton community.
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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 | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| 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".