Quick Search:    advanced search

GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help

This Article Figures Only Full Text Full Text (PDF) Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (17) Citing Articles via Google Scholar Google Scholar Articles by Nomaki, H. Articles by Kitazato, H. Search for Related Content GeoRef GeoRef Citation

BEHAVIOR AND RESPONSE OF DEEP-SEA BENTHIC FORAMINIFERA TO FRESHLY SUPPLIED ORGANIC MATTER: A LABORATORY FEEDING EXPERIMENT IN MICROCOSM ENVIRONMENTS

¹ Ocean Research Institute, University of Tokyo, Minamidai 1-15-1, Nakano-ku, Tokyo 164-8639, Japan. E-mail: nomaki{at}ori.u-tokyo.ac.jp
² Institute of Geosciences, University of Tuebingen, Sigwartstrasse 10, 72076 Tuebingen, Germany.
³ Department of Life and Earth Sciences, Shizuoka University, Ohya 836, Shizuoka 422-8529, Japan.
⁴ Institute for Research on Earth Evolution, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), 2-15 Natsushima-cho, Yokosuka 237-0061, Japan.

The behavior of deep-sea benthic foraminifera in response to seasonal inputs of food material was examined through feeding experiments. The experiments using sediments from Sagami Bay (1425 m water depth) containing living foraminifera were carried out using microcosms (aquaria) with thin-walled glass sides. Three different nutrient levels were tested in order to observe how benthic foraminifera reacted to deposited organic matter. Observations of both behavior and microhabitat segregation with respect to the sediment-water interface were conducted using a sideways-mounted binocular microscope. Benthic foraminifera were vertically distributed according to three types of microhabitat segregation patterns, comparable to those of natural populations in Sagami Bay: shallow infaunal, intermediate infaunal and deep infaunal. After addition of food into the aquaria, many foraminifera migrated upwards to a shallower part of the sediment and some foraminifera ingested food. Shallow and intermediate infaunal species reacted faster to newly deposited food materials than deep infaunal species. Among deep infaunal species, Globobulimina affinis reacted very slowly to added food, whereas Chilostomella ovoidea did not respond at all. Reactions to newly deposited organic matter observed in this experiment vary from one microhabitat to another. These different food preferences are an important factor for understanding foraminiferal microhabitats and the degradation of phytodetritus. The size distribution of foraminiferal tests after the experiment was completed suggests that some species reproduced during the experimental run, although there was no significant difference in total numbers of foraminifera between fed and unfed aquaria. Our results indicate that some benthic foraminifera may reproduce in response to organic matter arriving before the spring bloom.

This article has been cited by other articles:

				A. J. Gooday, H. Nomaki, and H. Kitazato Modern deep-sea benthic foraminifera: a brief review of their morphology-based biodiversity and trophic diversity Geological Society, London, Special Publications, January 1, 2008; 303(1): 97 - 119. [Abstract] [Full Text] [PDF]

				H. Nomaki, A. Yamaoka, Y. Shirayama, and H. Kitazato DEEP-SEA BENTHIC FORAMINIFERAL RESPIRATION RATES MEASURED UNDER LABORATORY CONDITIONS Journal of Foraminiferal Research, October 1, 2007; 37(4): 281 - 286. [Abstract] [Full Text] [PDF]

				G. Duchemin, C. Fontanier, F. J. Jorissen, C. Barras, and C. Griveaud LIVING SMALL-SIZED (63-150 {micro}m) FORAMINIFERA FROM MID-SHELF TO MID-SLOPE ENVIRONMENTS IN THE BAY OF BISCAY Journal of Foraminiferal Research, January 1, 2007; 37(1): 12 - 32. [Abstract] [Full Text] [PDF]