Geochemical Journal, Vol. 49 (No. 5), pp. 469-480, 2015
Kaoru Kubota,1,2 Yusuke Yokoyama,1,2,3* Yuta Kawakubo,1,2 Arisa Seki,1,2 Saburo Sakai,3 P. Ajithprasad,4 Hideaki Maemoku,5 Toshiki Osada6 and S. K. Bhattacharya7
1Atmosphere and Ocean Research Institute, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8564, Japan
2Department of Earth and Planetary Science, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Tokyo 113-0033, Japan
3Japan Agency for Marine-Earth Science and Technology, 2-15 Natsushima-cho, Yokosuka, Kanagawa 237-0061, Japan
4Department of Archaeology and Ancient History, Maharaja Sayajirao University of Baroda, Vadodara 390 002, India
5Department of Geography, Hosei University, 2-17-1 Fujimi, Tokyo 102-8160, Japan
6Research Institute for Humanity and Nature (Emeritus), 457-4 Motoyama, Kamigamo, Kita-ku, Kyoto 603-8047, Japan
7Research Center for Environmental Changes, Academia Sinica, Academia Road, Taipei 152, Taiwan R.O.C.
(Received March 9, 2015; Accepted May 12, 2015)
Understanding catfish ecology is important because catfish constitute one of the largest fish stocks in the coastal Indo-Pacific regions. Recent technological advances have enabled the use of biological electric sensors to understand fish ecology, but their application requires catch and release. Fish otoliths can record ecological changes, and oxygen isotopes and Sr/Ca ratios along the growth direction are independently used to reconstruct the migration history of the fish. Here we report high-resolution measurements of both oxygen isotopes and Sr/Ca ratios of a modern otolith from a marine catfish (Plicofollis tenuispinis) collected from the Gulf of Khambhat, western India. Both sets of data suggest that the catfish migrated from an estuarine environment to the sea during its lifetime. Migration history of the catfish was estimated with monthly resolution aided by numerical modeling. Potential applications of this analysis as an environmental recorder for variables such as temperature and water chemistry are examined.
Key words: otolith, oxygen isotope, carbon isotope, Sr/Ca, Ba/Ca