Wednesday, February 08, 2017Register
 Phylum: Granuloreticulosa (Shelled Protists)

The phylum Granuloreticulosa is made up of the classes Reticulomyxida (unshelled forams) and Foraminifera (shelled forams). Foraminifera are single-celled, shelled, amoeboid protists.  This group is almost entirely marine, with 951 species documented in the Gulf of Mexico.  Foraminifers are found in all marine environments, from shallow intertidal pools to the deep ocean.

10 species of Foraminifera [Image: Randolph Femmer , NBII Life, ]
10 species of Foraminifera [Image: Randolph Femmer, NBII Life, ]

Foraminifers range in size from 100 micrometers to 20 centimeters. The shells, or "tests," of protists are usually made of several hollow chambers separated by partitions, with openings called foramina that connect the chambers.  Shells are often made of sand grains or calcite.  Most of the species are benthic, living on shells or rocks or amongst the seaweed on the ocean floor. This group is an important part of the marine food web, as foraminifers serve as prey for snails, sand dollars and fish.

(Information from Gulf of Mexico Origin, Waters, and Biota: Volume 1, Biodiversity, Texas A&M University Press 2009).

Other Resources:

UC Berkely, Museum of Paleontology, Foraminifera



Image of 3 Foraminifera, After Chapman, 1902, from Gulf of Mexico Origin, Waters and Biota, Chapter 6, page 87
3 Foraminifera [Image: After Chapman, 1902, Gulf of Mexico Origin, Waters, and Biota, Chap 6, Pg 87

The chamber arrangements of forams can take many forms, with some displaying a more linear arrangement and others displaying a spiral arrangement.  This image above displays three different morphologies of foram shells: (from left to right) planispiral evolute, streptospiral, and trochospiral.

Click here for more information on foram shell (test) morphology from the University College London.

Privacy StatementTerms Of UseCopyright 2011 Houston Advanced Research Center

BorderBoxedBlueBoxedGrayBlueSmall width layoutMedium width layoutMaximum width layoutMaximum textMedium textSmall textBack Top!