Environmental controls on daily shell growth of Phacosoma japonicum (Bivalvia: Veneridae) from Japan

Abstract

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 336:141-150 (2007) - doi:10.3354/meps336141 Environmental controls on daily shell growth of Phacosoma japonicum (Bivalvia: Veneridae) from Japan Tsuzumi Miyaji1,*, Kazushige Tanabe1, Bernd R. Schöne2 1Department of Earth and Planetary Science, University of Tokyo, 7-3-1 Hongo, Tokyo 113-0033, Japan 2Increments Research Group, Department of Paleontology, Institute of Geosciences, University of Mainz, Johann-Joachim-Becher-Weg 21, 55099 Mainz, Germany *Email: [e-mail] ABSTRACT: This study examined the environmental factors controlling the daily shell deposition of the intertidal bivalve Phacosoma japonicum from Seto Inland Sea, west Japan, and Tokyo Bay, central Japan. Sclerochronological analyses of microgrowth patterns in marked-and-recovered specimens indicate that a pair of 2 etch-sensitive increments and 2 etch-resistant lines is formed every lunar day (duration 24.8 h). The accretionary pattern of the lunar day growth increments (LDGIs) reflects tidal cycles. Prominent growth lines were formed during spring tides, when the bivalves were subaerially exposed, and weak ones were deposited during neap tides, when they were continuously submerged. The bivalves stop secreting shell carbonate during winter and early spring. The time interval encompassed by the winter break in the specimens from Tokyo Bay lengthened as the shells grew older. Although seawater temperature is the main controlling factor for shell growth, a number of mutually related environmental factors such as salinity and food availability also affect shell growth. In Tokyo Bay, the broadest LDGIs were deposited between temperatures of 21 and 24°C. Our findings provide a basis for the interpretation of the temporal changes in shell microgrowth patterns in terms of environmental conditions of extant and fossil P. japonicum specimens. KEY WORDS: Sclerochronology · Bivalve mollusk · Shell growth · Tidal cycle · Seawater temperature Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 336. Online publication date: April 27, 2007 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2007 Inter-Research.