Rhizaria

Cholamonas (coal-a-moan-ass), cercomonad flagellate described early in the third millenium, with two subapically inserting flagella. Phase contrast micrograph.

Gymnochlora (jim-know-clore-a), one of the amoeboid algae but like other members of the chlorarachniophytes the plastids result from a secondary endosymbiotic event involving a eukaryotic green alga, a nucleomorph is present. With bright green plastids. Differential interference microscopy. data on this strain.

Gymnochlora (jim-know-clore-a), one of the amoeboid algae but like other members of the chlorarachniophytes the plastids result from a secondary endosymbiotic event involving a eukaryotic green alga, a nucleomorph is present. With bright green plastids and fine irregular pseudopodia. Differential interference microscopy. data on this strain.

Gymnochlora (jim-know-clore-a), one of the amoeboid algae but like other members of the chlorarachniophytes the plastids result from a secondary endosymbiotic event involving a eukaryotic green alga, a nucleomorph is present. Portrait of isolated cell with bright green plastids and fine granular pseudopodia. Differential interference microscopy. data on this strain.

Clathrulina, one of the desmothoracid protists. Stalk and lorica. Bright field.

Clathrulina (cla-through-line-a), showing head region and included amoeboid cell. This image shows the stiffened pseudopodia which led the desmothoracids to be regarded as a type of heliozoon. Differential interference contrast.

Clathrulina, desmothoracid flagellate, traditionally regarded as a kind of heliozoon. The trophic cell lives as an amoeba within a stalked lorica, and pseudopodia extend from the lorica. This reproduces to form a flagellated cell which leaves the lorica and establishes itself elsewhere. Phase contrast.

Clathrulina, one of the desmothoracid protists. Traditionally classified as the heliozoa because of the star-shaped appearance of the cell, but the heliozoa have always been a rag-bag of unrelated organisms. Desmothoracids may adopt one of several forms. A ‘mature’ trophont (feeding form) is an amoeboid organism with stiffened arms. It lives in an spherical (ish) organic lorica which has large openings. The chamber is borned on a hollow stalk, and several stalked loricae may be joined end to end or in a branching arrangement. The stiffened pseudopodia extend out of the openings to capture food. Division leads to the formation of flagellated cells one or all progeny vacate the lorica, swim around and then settle as an amoeba. The amoeba secrete a stalk and mucus, and the mucus is shaped and accretes to form a lorica. The lorica strengthens and thickens with age. This image is of a cell that has recently begun the process of creating a lorica. Differential interference contrast.

Clathrulina, one of the desmothoracid protists. Traditionally classified as the heliozoa because of the star-shaped appearance of the cell, but the heliozoa have always been a rag-bag of unrelated organisms. Desmothoracids may adopt one of several forms. A ‘mature’ trophont (feeding form) is an amoeboid organism with stiffened arms. It lives in an spherical (ish) organic lorica which has large openings. The chamber is borned on a hollow stalk, and several stalked loricae may be joined end to end or in a branching arrangement. The stiffened pseudopodia extend out of the openings to capture food. Division leads to the formation of flagellated cells one or all progeny vacate the lorica, swim around and then settle as an amoeba. The amoeba secrete a stalk and mucus, and the mucus is shaped and accretes to form a lorica. The lorica strengthens and thickens with age. This image is of the chamber of the lorica showing the openings. Differential interference contrast.

Clathrulina, one of the desmothoracid protists. Traditionally classified as the heliozoa because of the star-shaped appearance of the cell, but the heliozoa have always been a rag-bag of unrelated organisms. Desmothoracids may adopt one of several forms. A ‘mature’ trophont (feeding form) is an amoeboid organism with stiffened arms. It lives in an spherical (ish) organic lorica which has large openings. The chamber is borned on a hollow stalk, and several stalked loricae may be joined end to end or in a branching arrangement. The stiffened pseudopodia extend out of the openings to capture food. Division leads to the formation of flagellated cells one or all progeny vacate the lorica, swim around and then settle as an amoeba. The amoeba secrete a stalk and mucus, and the mucus is shaped and accretes to form a lorica. The lorica strengthens and thickens with age. This image is of aa mature trophont within the lorica chamber. Differential interference contrast.

Clathrulina, one of the desmothoracid protists. Traditionally classified as the heliozoa because of the star-shaped appearance of the cell, but the heliozoa have always been a rag-bag of unrelated organisms. Desmothoracids may adopt one of several forms. A ‘mature’ trophont (feeding form) is an amoeboid organism with stiffened arms. It lives in an spherical (ish) organic lorica which has large openings. The chamber is borned on a hollow stalk, and several stalked loricae may be joined end to end or in a branching arrangement. The stiffened pseudopodia extend out of the openings to capture food. Division leads to the formation of flagellated cells one or all progeny vacate the lorica, swim around and then settle as an amoeba. The amoeba secrete a stalk and mucus, and the mucus is shaped and accretes to form a lorica. The lorica strengthens and thickens with age. This image is of a cell in the lorica, pseudopodia can be seen. Differential interference contrast.Phase contrast micrograph.Phase contrast micrograph.

Clathrulina, one of the desmothoracid protists. Traditionally classified as the heliozoa because of the star-shaped appearance of the cell, but the heliozoa have always been a rag-bag of unrelated organisms. Desmothoracids may adopt one of several forms. A ‘mature’ trophont (feeding form) is an amoeboid organism with stiffened arms. It lives in an spherical (ish) organic lorica which has large openings. The chamber is borned on a hollow stalk, and several stalked loricae may be joined end to end or in a branching arrangement. This image shows the rootlet-like secretrions which attach the stalk to the substrate. Phase contrast micrograph.

Clathrulina, one of the desmothoracid protists. Traditionally classified as the heliozoa because of the star-shaped appearance of the cell, but the heliozoa have always been a rag-bag of unrelated organisms. Desmothoracids may adopt one of several forms. A ‘mature’ trophont (feeding form) is an amoeboid organism with stiffened arms. It lives in an spherical (ish) organic lorica which has large openings. The stiffened pseudopodia extend out of the openings to capture food. The central nucleus is also evident. Differential interference contrast.

Clathrulina, one of the desmothoracid protists. Traditionally classified as the heliozoa because of the star-shaped appearance of the cell, but the heliozoa have always been a rag-bag of unrelated organisms. Desmothoracids may adopt one of several forms. A ‘mature’ trophont (feeding form) is an amoeboid organism with stiffened arms. It lives in an spherical (ish) organic lorica which has large openings. The chamber is borned on a hollow stalk, and several stalked loricae may be joined end to end or in a branching arrangement. The stiffened pseudopodia extend out of the openings to capture food. Division leads to the formation of flagellated cells one or all progeny vacate the lorica, swim around and then settle as an amoeba. The amoeba secrete a stalk and mucus, and the mucus is shaped and accretes to form a lorica. The lorica strengthens and thickens with age. This image is of a young cell that is part way through the process of creating a lorica. Differential interference contrast.Phase contrast micrograph.

Clathrulina, one of the desmothoracid protists. Traditionally classified as the heliozoa because of the star-shaped appearance of the cell, but the heliozoa have always been a rag-bag of unrelated organisms. Desmothoracids may adopt one of several forms. A ‘mature’ trophont (feeding form) is an amoeboid organism with stiffened arms. It lives in an spherical (ish) organic lorica which has large openings. The chamber is borned on a hollow stalk, and several stalked loricae may be joined end to end or in a branching arrangement. The stiffened pseudopodia extend out of the openings to capture food. Division leads to the formation of flagellated cells one or all progeny vacate the lorica, swim around and then settle as an amoeba. The amoeba secrete a stalk and mucus, and the mucus is shaped and accretes to form a lorica. The lorica strengthens and thickens with age. This image shows several cells at different stages of development. Differential interference contrast.

Clathrulina (cla-through-line-a), showing head region and included amoeboid cell. Differential interference contrast.

Hedriocystis undergoing division within faceted stalked capsule. Axopodia protrude from pores in capsule. Daughter cells become flagellated, escape the lorica then secrete their own stalk and lorica. Two of the five species in the genus have a spherical non-faceted lorica. Recently, a new genus, Penardiophrys has been erected for the faceted desmothoracid species such as this one. From freshwater pond near Boise, Idaho. Phase contrast. See Mikrjukov,K. Taxonomy and Phylogeny of Heliozoa I. Acta Protozool 39:81-97, 2000.

Hedriocystis - portrait of a species with smooth non-faceted spherical lorica. Phase contrast. From a freshwater pond near Boise, Idaho.

Hedriocystis species within faceted stalked siliceous capsule. Axopodia protrude from pores in capsule. Two of the five species in the genus have a spherical non-faceted lorica. Recently a new genus, Penardiophrys has been erected for the faceted desmothoracid species such as this one. From freshwater pond near Boise, Idaho. Phase contrast. See Mikrjukov,K. Taxonomy and Phylogeny of Heliozoa I. Acta Protozool 39:81-97, 2000.

Hedriocystis, a small desmothoracid protist. The cell lives as an amoeba with stiffened arms (axopodia) within a loose lorica that has large holes or perforations. The lorica is stalked. When the cell divides, it may produce flagellated cells which leave the lorica and set up home elsewhere. From Lake Donghu, China. Phase contrast micrograph.

Hedriocystis has a cell body enclosed within an extracellular capsule which is either homogeneous or composed of regular polygonal facets; axopodia emerge from small perforations. Three species with long hollow stalk, one species without.

Dimorpha (die-morph-a), the genus contains helioflagellates in which there are two flagella and in which the axonemes terminate on a microtubule organizing centre located near the front of the cell. This is the motile form. Phase contrast.

Dimorpha (die-morph-a), the genus contains helioflagellates in which there are two flagella and in which the axonemes terminate on a microtubule organizing centre located near the front of the cell. Normally the arms do not branch and nor do they have strongly developed extrusomes, so this organism is identified only tentatively to this genus. This taxon may produce arm-less swimming cells, illustrated in another image. Phase contrast.