Ocean warming is predicted to have negative impacts on marine calcifying organisms. Larger benthic foraminifers (LBFs) are single-celled marine organisms with calcareous shells, and the third-highest carbonate producer in clear, shallow-water, tropical and subtropical, regions. Previous studies have reported declining shell growth when cultured at higher temperatures, although the specific physical characteristics of shell growth remain unknown because their small size and complex shell structures make it difficult to measure shell growth in three dimensions. To evaluate the effect of seawater temperature on LBF growth, we cultured a porcelaneous LBF Sorites orbiculus under six different temperature conditions (19 °C–29 °C) and quantitatively measured their shell volume, weight, maximum diameter, and chamber number, using micro X-ray computed tomography (MicroCT). Shell growth of S. orbiculus expressed by shell weight and volume is optimal around 25 °C, declining at lower and higher temperatures. Changes in shell weight were associated with variations in shell volume, but not shell density. MicroCT observations indicated that changes in shell volume and weight might be caused by symbiont activity. Our results suggest that suppressed LBF growth is currently occurring in summer months and might be further exacerbated in the future by rising ocean temperatures.

预计海洋变暖会对海洋钙化生物产生负面影响。较大的底栖有孔虫（LBF）是具有钙质壳的单细胞海洋生物，是清澈，浅水，热带和亚热带地区第三高的碳酸盐生产者。以前的研究报道，在较高温度下培养时，壳的生长会下降，尽管壳生长的具体物理特征仍然未知，因为它们的小尺寸和复杂的壳结构使得很难在三个维度上测量壳的生长。为了评估海水温度对LBF生长的影响，我们培养了一个多孔LBF Sorites orbiculus在六个不同的温度条件下（19°C–29°C），并使用微型X射线计算机断层扫描（MicroCT）定量测量了它们的壳体积，重量，最大直径和腔室数量。用壳的重量和体积表示的链球菌的壳生长在25°C左右为最佳，在较低和较高的温度下下降。壳重的变化与壳体积的变化有关，但与壳密度无关。MicroCT的观察结果表明，壳体积和重量的变化可能是由共生活性引起的。我们的结果表明，目前在夏季，LBF的生长受到抑制，未来可能会由于海洋温度升高而进一步加剧。