giant arborescent agglutinated foraminiferan Notodendrodes hyalinosphaira

Notodendrodes hyalinosphaira is a giant arborescent (tree structure) agglutinated (glues sediment grains around itself) foraminiferan, with some of its cell body below the sediment surface, encased by agglutinated shells, the innermost of which is composed of clear quartz grains --- an interesting example of particle selectivity [1,3]. N. hyalinosphaira has been described from specimens collected at Explorer's Cove, New Harbor, at depths from 10 to 35 meters [3]. In its most complex form, the unicellular N. hyalinosphaira has a buried spherical cell body with surrounding agglutinated layers up to two millimeters in diameter, a dendtritic 'root system' sprouting from the cell body, an umbilicus stretching from the cell body to the sediment surface, and then an arborescent structure stretching up to one centimeter above the sediment surface [3]. Well-developed specimens of N. hyalinosphaira can be up to 2.7 centimeters long, encompassing the root system to the arborescent structure [3]. N. hyalinosphaira differs from other agglutinated aborescent foraminifers by several characters, including the flower-like shape of its aborescent structure and the quartz-rich test surrounding its buried cell body [3]. N. hyalinosphaira feeds several ways: absorbing nutrients from the sediment through its dendritic 'root system', capturing very small prey from the sediment, parasitism of larger organisms, and taking particulate material from the water [3].

A foraminiferan is a unicellular organism, characterized by long, fine protrusions (pseudopodia) extending far away from their cytoplasmic body which is encased within a test or shell. There is always one nucleus but there may be a stage with multiple nuclei early in asexual reproduction. Foraminifera are a class within the kingdom Protista or Protoctista (depending on author's taxonomic preference) which encompasses eukaryote organisms like algae, protozoa and flagellate fungi. Foraminifera are almost entirely marine and are one of the most abundant marine invertebrates, playing a major role in the marine environment. Bottow-dwelling (benthic) foraminiferans occur in most marine environments, particularly in deepsea and outer continental shelf muds. Foraminiferans as a group may eat live food (bacteria, unicellular algae, especially diatoms, other protozoa, and small crustaceans such as copepods which are snared in their pseudopodia) or dead material (dead organisms, organic-rich grains including fecal pellets, particulate organic detritus, and colloidal organic molecules). These broad food preferences make them ideally adapted to the benthic environment.

Taxonomic Note: Earlier work on this organism while it was undescribed called it the 'flower foraminifer' [3].

1: Sam Bowser, personal communication, 2000; 2: Nature 289(5795):287-289, 1981; 3: Journal of Foraminiferal Research 32:177-187, 2002

Text ©Peter Brueggeman. Photograph ©Robert Sanders (Sam Bowser/S043 archives). Photograph may not be used in any form without the express written permission of Robert Sanders (Sam Bowser/S043 archives).