''Eudorina'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

green algae The green algae (: green alga) are a group of chlorophyll-containing autotrophic eukaryotes consisting of the phylum Prasinodermophyta and its unnamed sister group that contains the Chlorophyta and Charophyta/ Streptophyta. The land plants ...

in the family

Volvocaceae The Volvocaceae are a family of unicellular or colonial biflagellates algae, including the typical genus ''Volvox'', and are collectively known as the volvocine algae. The family was named by Ehrenberg in 1834, and it is known in older classifi ...

, containing about seven species. It has a

cosmopolitan distribution In biogeography, a cosmopolitan distribution is the range of a taxon that extends across most or all of the surface of the Earth, in appropriate habitats; most cosmopolitan species are known to be highly adaptable to a range of climatic and en ...

in freshwater habitats.

Description

''Eudorina'' colonies typically consist of 16, 32 or 64 cells, each of which is similar to ''

Chlamydomonas reinhardtii ''Chlamydomonas reinhardtii'' is a single-cell green alga about 10 micrometres in diameter that swims with two flagella. It has a cell wall made of hydroxyproline-rich glycoproteins, a large cup-shaped chloroplast, a large pyrenoid, and a ...

''. These cells are bedded within an extracellular matrix composed of glycoproteins. Colonies are spherical and motile, with motility derived from the flagellated individual cells. Cells are ovoid or spherical, each with two equal flagella. (In one species ''

Eudorina compacta ''Eudorina'' is a genus of green algae in the family Volvocaceae, containing about seven species. It has a cosmopolitan distribution in freshwater habitats. Description ''Eudorina'' colonies typically consist of 16, 32 or 64 cells, each of whi ...

'', the cells essentially touch each other, and are strikingly angular due to mutual compression.) There is a single cup-shaped

chloroplast A chloroplast () is a type of membrane-bound organelle, organelle known as a plastid that conducts photosynthesis mostly in plant cell, plant and algae, algal cells. Chloroplasts have a high concentration of chlorophyll pigments which captur ...

with one (basal) or multiple

pyrenoid Pyrenoids are sub-cellular phase-separated micro-compartments found in chloroplasts of many algae,Giordano, M., Beardall, J., & Raven, J. A. (2005). CO2 concentrating mechanisms in algae: mechanisms, environmental modulation, and evolution. ''An ...

s) and a stigma. Multiple contractile vacuoles are scattered throughout the cytoplasm. ''Eudorina'' is facultatively sexual, meaning colonies can reproduce either sexually or asexually. During development, each ''Chlamydomonas''-like cell undergoes several rounds of division to form plakeas, which then invert to form daughter colonies before hatching out of the mother colony. Sexual reproduction is

anisogamous Different forms of anisogamy: A) anisogamy of motile cells, B) 283x283px Anisogamy is a form of sexual reproduction">egg cell">oogamy (egg cell and sperm cell), C) anisogamy of non-motile cells (egg cell and spermatia).">283x283px Anisogamy is ...

; cells divide successively and differentiate into sperm packets, or develop into female gametes (without division). Eudorina elegans phv

Taxonomy

Although the most common species of ''Eudorina'' (''E. elegans'') is very different from the most common species of ''

Pandorina ''Pandorina'' is a genus of green algae in the family Volvocaceae. It is a common freshwater genus, and has a cosmopolitan distribution. Along with other algae such as '' Volvox'', '' Eudorina'' and ''Chlamydomonas'', it is a model organism for s ...

'' (''P. morum''), forms intermediate in morphology between ''Eudorina'' and ''Pandorina'' exist, such as ''Pandorina/Eudorina charkowiensis'' and ''Pandorina unicocca''. These have been reclassified to other genera, namely '' Colemanosphaera'' and '' Yamagishiella'', respectively. In particular, ''Eudorina'' is very similar to ''Yamagishiella'', differing mainly in its mode of reproduction (anisogamous in ''Eudorina'', isogamous in ''Yamagishiella'') and number/placement of contractile vacuoles.

Molecular phylogenetic Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...

studies show that ''Eudorina'' is

paraphyletic Paraphyly is a taxonomic term describing a grouping that consists of the grouping's last common ancestor and some but not all of its descendant lineages. The grouping is said to be paraphyletic ''with respect to'' the excluded subgroups. In co ...

with respect to ''

Pleodorina ''Pleodorina'' is a genus of colonial green algae in the family Volvocaceae. It occurs in freshwater habitats and has a cosmopolitan distribution. Description ''Pleodorina'' consists of motile colonies of 32 to 128 cells, which are arranged in ...

'' and ''

Volvox ''Volvox'' is a polyphyletic genus of chlorophyte green algae in the family Volvocaceae. ''Volvox'' species form spherical colonies of up to 50,000 cells, and for this reason they are sometimes called globe algae. First reported by Antonie van L ...

'' (excluding section ''Volvox''). Taxonomically, ''Eudorina'' has been confused with ''

''. In particular, ''

Eudorina illinoisensis ''Eudorina'' is a genus of green algae in the family Volvocaceae, containing about seven species. It has a cosmopolitan distribution in freshwater habitats. Description ''Eudorina'' colonies typically consist of 16, 32 or 64 cells, each of whi ...

'' (syn. ''Pleodorina illinoisensis'') blurs the boundaries between the two genera by having four anterior cells which are facultatively

somatic Somatic may refer to: * Somatic (biology), referring to the cells of the body in contrast to the germ line cells ** Somatic cell, a non-gametic cell in a multicellular organism * Somatic nervous system, the portion of the vertebrate nervous syst ...

. Currently, ''Eudorina'' is distinguished from ''Pleodorina'' by the absence or presence of obligately somatic cells. Phylogenetic relationships are as follows (not all species of ''Eudorina'' are included:

References

External links

Eudorina
- Description with pictures {{Taxonbar, from=Q310125 Chlamydomonadales Chlamydomonadales genera