Seascape ecological view as a new insight of benthic foraminiferal community

Abstract

<p>Foraminifers secrete various chemicals for chamber walls. They are calcium carbonates such as calcite, aragonite, Mg-calcite, organic compounds for agglutinated chambers and/or organic cemented test walls. &#160;Foraminiferal test walls basically form according to genetic information.&#160; However, same test group is tended to gather at specific microenvironments.&#160; For instance, turf shaped algal microhabitat such as coralline algae at rocky shore is composed of both frond and thallus parts as microhabitat.&#160; Frond part is open space where fresh seawater moves inbetween one frond and the other.&#160; <em>Elphidium crispum</em>, <em>Pararotalia nipponica</em> and <em>Patellina corrugate</em> and other calcareous foraminifers dwell at frond surface.&#160; In contrast, thallus part is muddy and high concentration of organic matters.&#160; The thallus part shows less oxygenated than frondal part as the space is close.&#160; Microbial cascades are developed at thallus part.&#160; Minor elements such as Mg or Sr are relatively high in sediment.&#160; Soft-shelled forms such as <em>Allogromia</em>, gromiid, agglutinated forms and miliolids groups with high magnesian calcite tests flourish at the thallus part.</p><p>Microhabitat segregation and microenvironmental differences may cause similar biomineralization of benthic foraminiferal tests.&#160; I would like to stress that micro-seascape should be important to characterize benthic foraminiferal assemblages.</p>