Ochrophyta
The Ochrophyta, also known as the Heterokontophyta, are a large and diverse group of algae, encompassing a wide range of photosynthetic organisms found in both freshwater and marine environments. They are characterized by their unique cell structure, containing chloroplasts derived from secondary endosymbiosis, which gives them their characteristic golden-brown color. Ochrophyta play a crucial role in marine ecosystems as primary producers, forming the base of many food webs.
Common Names
Ochrophyta are commonly referred to as golden algae, diatoms, brown algae, and yellow-green algae, reflecting the diverse colors and appearances of different groups within the phylum.
Characteristics
The distinguishing features of Ochrophyta include:
- Chloroplasts with chlorophyll a and c: This pigment combination gives Ochrophyta their characteristic golden-brown color.
- Unique cell wall structure: Many Ochrophyta have cell walls composed of silica (diatoms) or cellulose (brown algae).
- Heterokont flagellation: They possess two flagella of unequal length and structure, one being smooth and the other being hairy.
- Diverse life cycles: Ochrophyta exhibit a variety of life cycles, ranging from simple unicellular forms to complex multicellular organisms.
Environments
Ochrophyta are ubiquitous in aquatic environments, including:
- Marine waters: Diatoms are particularly abundant in the oceans, forming a significant portion of phytoplankton.
- Freshwater habitats: Ochrophyta are also found in lakes, ponds, and rivers.
- Terrestrial habitats: Some Ochrophyta, such as the yellow-green algae, can be found in moist terrestrial environments.
References
For further information on Ochrophyta, consult the following reliable sources: