[A-OS15] 海洋化学・生物学

[AOS15-P05] 海洋浮遊物に付着するカルエボシの不均質な殻成長

*渡部 裕美¹、長井 裕季子¹、坂井 三郎¹、小林 元樹²、山守 瑠奈³、多田 訓子¹、西川 悠¹、桑谷 立¹、上原 春香⁴、遊佐 陽一⁴ (1.海洋研究開発機構、2.石巻専修大学、3.京都大学瀬戸臨海実験所、4.奈良女子大学)

キーワード：biomineralization、pelagic、carbonate

Floating materials of both natural and anthropogenic origin can affect marine ecosystems and human economic activities. Although the tracking and forecasting of floating materials are important, these processes are difficult to trace back after the events of origins, such as tsunamis and underwater volcanic eruptions. The goose barnacle Lepas anserifera, a rapid colonizer in pelagic environments, is a potential "natural logger" of floating materials. In this study, we performed temperature-controlled culture experiments and growth line identification in the laboratory to quantify the growth increments of individual shells consisting of the capitulum of L. anserifera and to examine the effects of the temperature on their growth. Following calcein staining, the growth line of L. anserifera was visualized under a fluorescent microscope, and gross (capitular length and width) and individual (scutum and tergum) shell growth were compared. Shells grew in twice as much in the CL direction than in the CW direction owing to the larger growth increases in the scutum than in the tergum. Growth increments were unaffected by temperatures from 20°C to 30°C, although growth appeared somewhat limited after August. The stable oxygen isotope composition (δ18O) of the shells represented the water temperature as previously known, and the present results showed that the scutum had heavier δ18O than the tergum in most cases. Further understanding for the biomineralization process of barnacles is required for the precise application of environmental proxies in barnacle shells.