O. Gross, Influence of temperature, oxygen and food availability on the migrational activity of bathyal benthic foraminifera: evidence by microcosm experiments, HYDROBIOL, 426(1-3), 2000, pp. 123-137
Foraminifera are a dominant group of amoeboid protists in the deep-sea and
play possibly a significant role in decomposition processes of incoming org
anic matter. In order to study the poorly known ecology of these protozoans
, microcosm experiments with living bathyal benthic foraminifera have been
conducted. Foraminifera from 2880 m and shallower water depths were success
fully maintained and their movement patterns investigated. By video documen
tation, high mean migration speed of 20,02 (N = 22) and 24,48 mu m min(-1)
(N = 10) at 4 degrees C were found for species such as Hoeglundina elegans
and Quinqueloculina seminula from 1847 m and 1921 m water depth, respective
ly. The results demonstrate that some bathyal foraminifera have migration s
peeds comparable to those of shallow water species. Environmental factors s
uch as temperature, food concentration and oxygen content showed a marked i
nfluence on the migration of some species. An increase in temperature from
10 degrees C to 15 degrees C resulted in an increase of 35% in the migratio
n speed of Allogromia spp. However, other species reacted differently. High
er food concentration resulted in a decrease in speed of some species. Whil
e in Quinqueloculina lamarckiana speed was not greatly affected by a low ox
ygen content in the sediment, other foraminifera responded to oxygen deplet
ion by migration to the surface layers. Observations of benthic foraminifer
a in the laboratory microcosms are discussed in relation to microhabitats a
nd the fate of organic matter on the sea floor and in the sediment.