Amplexidiscus
Amplexidiscus is a genus of single-celled marine organisms belonging to the class Bacillariophyceae, commonly known as diatoms. Diatoms are microscopic algae that are responsible for a significant portion of the Earth’s primary productivity, playing a crucial role in the global carbon cycle. The genus Amplexidiscus is characterized by its unique morphology, displaying distinctive features that distinguish it from other diatoms.
Common Names
Amplexidiscus does not have widely recognized common names. However, it is often referred to simply as "Amplexidiscus diatom" or "Amplexidiscus species" in scientific literature.
Characteristics
Amplexidiscus diatoms are known for their distinctive circular or nearly circular valves, which are the two halves of the diatom frustule. The valves are typically ornamented with intricate patterns of ridges, pores, or spines. One of the most notable characteristics of Amplexidiscus is the presence of a central, dome-shaped structure called the "umbo" that protrudes from the valve face. This umbo can be smooth or ornamented with additional features, depending on the species.
Other distinctive features of Amplexidiscus include:
- A ring of small, rounded processes called "marginal fultoportulae" that encircle the valve margin.
- A series of radial lines extending from the central umbo towards the valve margin, known as "costae".
- The presence of a girdle band that connects the two valves.
Environments
Amplexidiscus diatoms are primarily found in marine environments, particularly in the pelagic zone, which is the open ocean water column. These diatoms are often associated with oligotrophic waters, which are nutrient-poor environments. They are generally considered to be planktonic, meaning that they drift with the currents and are not attached to a substrate.
References
For further information on Amplexidiscus, you can consult the following references: