Hydrodictyaceae
Family of algae
From Wikipedia, the free encyclopedia
Hydrodictyaceae is a family of green algae in the order Sphaeropleales.[1] They are found in freshwater habitats worldwide.[2]
| Hydrodictyaceae | |
|---|---|
| |
| Pediastrum | |
Scientific classification  | |
| Domain: | Eukaryota |
| Clade: | Archaeplastida |
| Clade: | Viridiplantae |
| Division: | Chlorophyta |
| Class: | Chlorophyceae |
| Order: | Sphaeropleales |
| Family: | Hydrodictyaceae Dumortier, 1829 |
| Genera[1] | |
|
See text | |
Members of this family are either unicellular or colonial. Cells are cylindrical, polyhedral, spherical, or sometimes nearly spherical. Cells contain a single parietal, chloroplast with a pyrenoid.[3] The cell wall may be smooth or covered in warts, ribs or other ornamentation.[4]
Reproduction can occur asexually or sexually. In asexual reproduction, the mother cell becomes a number of zoospores and swim inside the enlarged mother cell wall, until they attach to each other and become a new colony. In Tetraedron, the cells do not produce zoospores but produce autospores within the enlarged mother cell wall. Sexual reproduction, when observed, occurs via isogamous gametes.[2]
Because the cell wall of some Hydrodictyaceae contain sporopollenin, they decay very slowly and thus last long in the fossil record.[5]
Genera
The family Hydrodictyaceae includes the following genera:[1]
- Euastropsis
- Helierella
- Hydrodictyon
- †Hydrodictyopsis
- Lacunastrum
- Monactinus
- Parapediastrum
- †Pediastrites
- Pediastrum
- Pseudopediastrum
- Sorastrum
- Sphaerastrum
- Stauridium
- Tetraedroides
- Tetraedron
- Tetrapedia
Traditionally, the genus Tetraedron was excluded and placed within the Chlorellaceae, because of autospore formation.[2] However, the genus produces autospores within an enlarged cell wall, similar to Pediastrum, and molecular phylogenetic evidence shows that they are related.[2]
Molecular phylogenetic studies suggest the following relationships:[2][6][7][8][9]
| Hydrodictyaceae |
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Neochloridaceae (outgroup) | |||||||||||||||||||||||||||||||||||||||||||||||||
