The distinct roles of two intertidal foraminiferal species in phytodetrital carbon and nitrogen fluxes – results from laboratory feeding experiments

Author(s)

Julia Wukovits, Max Oberrauch, Annekatrin Enge, Petra Heinz

Abstract

Benthic foraminifera play a major role as primary consumers and detrivores redistributing organic carbon and nitrogen in intertidal environments. Here we compared the differences of phytodetrital carbon and nitrogen intake and turnover of two dominant intertidal foraminifera, Ammonia tepida and Haynesina germanica. Their lifestyles in relation to feeding behavior (feeding preferences, intake and turnover of phytodetrital carbon and nitrogen) and temperature adaptations were compared to obtain a closer definition of their specific roles in intertidal organic matter processing. For this comparison, we carried out a series of shortterm laboratory incubations with stable-isotope-labeled (

¹³C and

¹⁵N) detritus as the food source. We compared the response of the two species to diatom detritus at three different temperatures (15, 20, 25 °C). Ammonia tepida showed a very high, temperature-influenced intake and turnover rates with more excessive carbon turnover, compared to nitrogen. The fairly low metabolic nitrogen turnover in H. germanica was not affected by temperature and was higher than the carbon turnover. This might be related with the chloroplast husbandry in H. germanica and its lower demands for food-derived nitrogen sources. Ammonia tepida prefers a soft chlorophyte food source over diatom detritus, which is harder to break down. In conclusion, A. tepida shows a generalist behavior that links with high fluxes of organic matter (OM). Due to its high rates of OM processing and abundances, we conclude that A. tepida is an important key player in intertidal carbon and nitrogen turnover, specifically in the short-term processing of OM and the mediation of dissolved nutrients to associated microbes and primary producers. In contrast, H. germanica is a highly specialized species with low rates of carbon and nitrogen budgeting.

Organisation(s)

Department of Palaeontology

External organisation(s)

University of Vienna

Journal

Biogeosciences

Volume

15

Pages

6185-6198

No. of pages

14

ISSN

1726-4170

DOI

https://doi.org/10.5194/bg-15-6185-2018

Publication date

10-2018

Peer reviewed

Yes

Austrian Fields of Science 2012

106021 Marine biology, 105118 Palaeontology

Keywords

ASJC Scopus subject areas

Earth-Surface Processes, Ecology, Evolution, Behavior and Systematics

Sustainable Development Goals

SDG 14 - Life Below Water

Portal url

https://ucrisportal.univie.ac.at/en/publications/b423e4a2-47f8-4f73-8241-1a85fd848c42