Dataset: Temperature-growth rate curves for Thalassiosira pseudonana

We cultured Thalassiosira pseudonana strain NCMA 1335 (formerly 3H) form a single cell (isolated by plating on agar) and sub-cultured 5 replicate populations into 20 ml of L1 marine culture medium in 50 ml tissue culture flasks at 16°C and 5 at 31°C. Per-capita growth rate was ~1 per day at both temperatures. Cultures were agitated daily to maintain cells in suspension, and 1,000,000 cells transferred to fresh L1 marine culture medium every 4 d for 350 generations (~2 y) of experimental temperature selection. Flasks had breathable, sterile caps, allowing for gas exchange. After ~350 generations, we assayed the per-capita population growth rates of all 5 replicate populations from each selection temperature at 10 temperatures, roughly spanning the previously recorded thermal niche of T. pseudonana, acclimating sub-cultured populations at each assay temperature for ~12 generations prior to the assay. Acclimation times ranged from ~10 d at near‐optimal temperatures to more than a month at 3°C. We estimated daily change in optical density using a spectrophotometer (see below). Assay times ranged from 4-14 d. We estimated per-capita growth rates by natural log-transforming densities and fitting a linear regression to the exponential portion of the growth curve.

We sampled daily during selection and assays by placing each entire tissue culture flask in a Shimadzu UV‐2401PC spectrophotometer (Shimadzu Corporation, Kyoto, Japan) and measuring absorbance at 436 nm (the wavelength corresponding to the absorbance maximum of chlorophyll a. Density data were log-transformed and linear regressions fit using R statistical programming language version 3.3.2.