[BPT04-P05] Effects on larger benthic foraminiferal shell density under global warming
Keywords:Larger benthic foraminifer, shell density, micro CT, laboratory experiments, global warming
In this study, we cultured the LBF Sorites orbiculus in filtered sea water until reproduction. Soon after S. orbiculus reproduced, clonal individuals from same mother individual were picked and separated into seven groups. One group was selected as initial stage sample, and other six groups were provided for culture experiments. We cultured each groups under six different temperature conditions (19, 21, 23, 25, 27 and 29 °C). Because clonal specimens were reproduced asexually from same individual, it was expected the genetic factors were kept to a minimum. We used micro CT to investigate mean CT number (proxy of density), shell volume, test diameter and chamber number of every clonal specimen after culturing. The results show the high correlation of mean CT number with temperature in contrast to the correlation of shell volume and temperature. This suggests changing in temperature of sea water causes shell density difference, furthermore, LBFs build the higher density shell in the higher temperature as long as they lives in 19 to 29 C° environment.