Living Behaviors of Benthic Foraminifera from Eastern Bahrain and the Saudi Coastline

The benthic foraminifera are among the major carbonate producers in modern Arabian Gulf waters and are found living in all marine habitats. They have been recognized as proxies to assess paleoenvironmental changes, however, their biological behavior in modern environments needs to be further studied. The current study attempts to explain the biology of benthic foraminifera in terms of their living behaviors (locomotion, survival, response to external stimuli, and reproductive strategy), from different regions of the western side of the Arabian Gulf. Accordingly, two major groups of benthic foraminifera, namely rotaliids and miliolids, are examined under laboratory conditions. Results illustrate that the rotaliids are more resistant to environmental changes than miliolids, as their granular reticulopodial network is stronger than among the miliolids, with high cytoplasmic streaming. The pseudopodia extend out from both primary and secondary apertures, and aid the organism in locomotion by attaching to the wall of hard substrate. As a result, they drag their whole bodies toward the direction of motion. In rotaliids, the movement rate is high and is attributed to the extension of pseudopodia through all apertures, compared with miliolids in which pseudopodia extend out from the primary aperture only. The innate behavior of both groups was observed as a function of external stimulus, i.e., light, nutrients, and availability of substrate. Lastly, the observation on the average life span indicates that the rotaliids are able to survive longer than miliolids. It is suggested that further studies on living behaviors should be conducted for different species towards better understanding of foraminiferal responses.