Growth and Fecundity of <i>Marginopora Vertebralis</i> and <i>Amphistegina Lobifera</i> in Laboratory Culture
Bibliographic record
Abstract
ABSTRACT The shells of large benthic foraminifers (LBF) are key contributors to the development and maintenance of coastal landforms in the Pacific as well as to Paleogene and Miocene carbonates deposited along the Neotethys Seaway and tropical Pacific islands. The current study assessed growth and fecundity of two species, Marginopora vertebralis and Amphistegina lobifera, collected from sites in Viti Levu, Fiji, based on shell diameter, shell weight, fecundity, and survival. Specimens were cultured without supplemental nutrients or food for 15 months under controlled laboratory conditions. Physicochemical parameters, including salinity, alkalinity, pH, and temperature, varied by <5% throughout the experiment. Asexual reproduction by M. vertebralis produced ∼270 offspring per brood, while A. lobifera produced ∼500 offspring per brood. The minimum size at reproduction for M. vertebralis was 15 mm, and A. lobifera reproduction occurred at diameters ≥0.9 mm. These observations were consistent with those of previous studies that predicted asexual fecundity related to parent size. Four non-linear mathematical functions (exponential, Gompertz, logistic, and von Bertalanffy) were compared to describe the age-weight relationship for each species. Results revealed that the logistic model best fits M. vertebralis growth, and von Bertalanffy model best fits A. lobifera growth. The growth model for A. lobifera predicted trends in juvenile growth and maximum size consistent with a previously published von Bertalanffy model based on cultures in which the foraminifers were provided nutrient sources and grew much faster than those observed in this study. These observations support published hypotheses that many LBF are exceptionally well-adapted to extreme oligotrophy, a characteristic that accounted for their dominance as carbonate producers in the Paleogene and Miocene of the Neotethys and Pacific islands.
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 | 0.000 |
| 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".