TY - JOUR
T1 - The daily growth band patterns of Tridacna derasa – Evidence from culture experiments
AU - Yang, Haotian
AU - Liu, Chengcheng
AU - Yang, Yanan
AU - Liu, Shan
AU - Wang, Guozhen
AU - Li, Jun
AU - Zhou, Pengchao
AU - Wen, Hanfeng
AU - Dodson, John
AU - Li, Xuxiang
AU - Yan, Hong
N1 - Publisher Copyright:
© 2026 China University of Geosciences (Beijing) and Peking University
PY - 2026/5
Y1 - 2026/5
N2 - Biogeochemical archives, such as tree rings and corals, with yearly-to-monthly resolution, have been used to reconstruct past climate change. However, they can not reconstruct weather events that occurred on daily-hourly time scales. Tridacna, the largest bivalve in the world, inhabiting the tropical and subtropical Pacific-Indian Ocean regions, exhibits daily growth bands measuring ∼5 to ∼60 μm and has the facility for reconstructing past extreme weather events. However, the precise daily growth band patterns across a day remain unclear, hindering any comprehensive understanding of the daily growth band patterns of Tridacna and their climatic implications. In this study, a 30-day controlled culture experiment on Tridacna derasa was carried out to address this and explore the main factors influencing the hourly Sr/Ca profiles. Results demonstrated that wide dim increments formed during daytime while narrow bright lines formed at nighttime. The hourly Sr/Ca profiles exhibited clear daily cycles synchronized with light cycles, with higher Sr/Ca at night and lower Sr/Ca values during daytime. The Sr/Ca ratios were not constant even under constant water temperature and light intensity, suggesting a limited influence of external environment factors and highlighting the role of internal biological regulation in Sr/Ca variation. A hypothesis was proposed here: During daylight, light-driven enzymatic activity coupled with H+ removal mechanisms regulates and lowers the Sr/Ca ratio, but the enzyme species and activities may be different, thus leading the variability of Sr/Ca at the identical light intensity; During nights, the organic matrix regulation mechanisms in extrapallial fluid (EPF) predominates, leading to higher Sr/Ca values, but the composition and concentration of organic matrix are not constant, leading to the variability of nightly Sr/Ca. Our findings provide a research foundation for paleoweather/paleoenvironment studies based on Tridacna.
AB - Biogeochemical archives, such as tree rings and corals, with yearly-to-monthly resolution, have been used to reconstruct past climate change. However, they can not reconstruct weather events that occurred on daily-hourly time scales. Tridacna, the largest bivalve in the world, inhabiting the tropical and subtropical Pacific-Indian Ocean regions, exhibits daily growth bands measuring ∼5 to ∼60 μm and has the facility for reconstructing past extreme weather events. However, the precise daily growth band patterns across a day remain unclear, hindering any comprehensive understanding of the daily growth band patterns of Tridacna and their climatic implications. In this study, a 30-day controlled culture experiment on Tridacna derasa was carried out to address this and explore the main factors influencing the hourly Sr/Ca profiles. Results demonstrated that wide dim increments formed during daytime while narrow bright lines formed at nighttime. The hourly Sr/Ca profiles exhibited clear daily cycles synchronized with light cycles, with higher Sr/Ca at night and lower Sr/Ca values during daytime. The Sr/Ca ratios were not constant even under constant water temperature and light intensity, suggesting a limited influence of external environment factors and highlighting the role of internal biological regulation in Sr/Ca variation. A hypothesis was proposed here: During daylight, light-driven enzymatic activity coupled with H+ removal mechanisms regulates and lowers the Sr/Ca ratio, but the enzyme species and activities may be different, thus leading the variability of Sr/Ca at the identical light intensity; During nights, the organic matrix regulation mechanisms in extrapallial fluid (EPF) predominates, leading to higher Sr/Ca values, but the composition and concentration of organic matrix are not constant, leading to the variability of nightly Sr/Ca. Our findings provide a research foundation for paleoweather/paleoenvironment studies based on Tridacna.
KW - Daily growth band
KW - Internal biological regulation
KW - Organic matrix
KW - Sr/Ca
KW - Tridacna
UR - https://www.scopus.com/pages/publications/105029725863
U2 - 10.1016/j.gsf.2026.102265
DO - 10.1016/j.gsf.2026.102265
M3 - 文章
AN - SCOPUS:105029725863
SN - 1674-9871
VL - 17
JO - Geoscience Frontiers
JF - Geoscience Frontiers
IS - 3
M1 - 102265
ER -
可持续发展目标 13 气候行动