Trace/minor element signatures (D Cd , D Ba , D Mg , and D Sr ) were measured in the tests (shells) of benthic foraminifera cultured in a trace-metal-concentration-controlled system. The culture system was constructed of inert materials and designed to limit microhabitat effects. This system ensured that variation observed in cultured foraminiferal element:calcium (TE/Ca) signatures was due to biologically mediated (vital) effects only. Two species, Bulimina aculeata and Rosalina vilardeboana, reproduced prolifically during two 4-to-8-month culture periods. In every case (i.e., for both species and each element), the inter-individual variability was larger than the analytical precision. Mean (±1 standard deviation) D E signatures for B. aculeata were: D Cd : 1.5±0.4, D Ba ×10: 2.1±0.7, D Mg ×1000: 0.62±0.15, and D Sr ×10: 1.5±0.1. Cultured B. aculeata D Mg , calibrated from culture and core-top (live) field specimens, predicted temperatures within ±2.0°C. The observed inter-individual variability from culture specimens was as large or larger than comparable results from core-top investigations. R. vilardeboana D Cd signatures were significantly lower, while D Ba , D Mg , and D Sr signatures were significantly higher than B. aculeata values. Since our culture system minimizes microhabitat variability, the variation in measured TE/Ca ratios suggests that biological processes are a significant factor in inter-individual and inter-species variability. Comparison of cultured and field-collected foraminiferal D Ba signatures supports previous findings that pore-water chemistry is a major environmental influence on foraminiferal test chemistry.