Chaetoceros


Chaetoceros is probably the largest genus of marine planktonic diatoms with approximately 400 species described, although many of these descriptions are no longer valid. It is often very difficult to distinguish between different Chaetoceros species.[1][2] Several attempts have been made to restructure this large genus into subgenera and this work is still in progress.[3][4] However, most of the effort to describe species has been focused in boreal areas, and the genus is cosmopolitan, so there are probably many tropical species still undescribed.[5]Some species are known from the fossil record, from the Quaternary of Sweden. It is the type genus of its family.

The genus Chaetoceros were first described by Ehrenberg in 1844.
Cells are more or less rectangular in girdle view.
Cells are usually elliptical in valve view.
Opposite setae of adjacent cells touch near their origin.

Each frustule has four siliceous processes called mushrooms or thorns that allow them to stay together forming colonies.

Chaetoceros is primarily a marine genus, but there are also accounts of species within inland waters of the United States. It is a type of centric diatom that contains a frustrule or cell wall composed of silica that contain long, thin spines (setae). The spines connect the frustules together creating a colony of cells.[6] Cells colonies can form chains that are coiled, straight, or curved. Cell size can range from <10 um to 50 um.[7]

Depth range (m): 0–470
Temperature range (°C): -1.952–29.468
Nitrate (μmol L-1): 0.053 - 34.037
Salinity: 18.564 - 37.775
Oxygen (mL L-1): 4.139 - 9.192
Phosphate (μmol L-1): 0.046 - 2.358
Silicate (μmol L-1): 0.648 - 92.735
[8]

Due to its high growth rates, research has been conducted to potentially use of Chaetoceros in biotechnology.[6][9] Some Chaetoceros species are well-established commercial aquacultures.[10][11][12] Many of them are recognized as generally good producers of useful lipids and other biologically active products with high value-added. They have enormous potential for producing nutraceuticals and biofuel.[13][14]


Phytoplankton – such as this colony of Chaetoceros socialis – naturally give off fluorescent light as they dissipate excess solar energy that they cannot consume through photosynthesis.
Bright-field microscopy image of epiphytic cyanobacterial symbiont Calothrix rhizosoleniae SC01 9 (indicated by arrows) attached to a host diatom Chaetoceros sp. (c). Scale bar, 50 μm.