Halteria plankton feeding on viruses 

(MainsGS3:Science and Technology- developments and their applications and effects in everyday life.)

Context:

• A new study by researchers at the University of Nebraska-Lincoln have reported that a particular genus of plankton can consume viruses as well as “grow and divide given only viruses to eat”. 

Feeding on viruses:

• Viruses  have a peculiar biology i.e. while inert outside a living body , but inside, they hijack the cellular machinery to feed, replicate and spread.
• We already know of other cells that can ‘consume’ viruses in an effort to destroy them such as the macrophage cells of the human immune system but the difference lies in being able to ‘eat’ viruses to fulfill one’s biological imperatives.
• Plankton of the genus Halteria can each consume 10,000 to a million virus particles a day, increase their population using the metabolised energy, and provide more food for the zooplanktons that consume the Halteria.

About Halteria plankton:

• Plankton are microscopic organisms that can only move with a current and they don’t have any facilities to actively propel themselves. 
• Halteria plankton are ciliates, meaning they have hair-like structures called cilia on their surface so sometimes they can beat some of these cilia to jump short distances, but not often as it they can’t do this often because it requires too much energy.
• Halteria plankton are found in large numbers in freshwater bodies and are heterotrophs meaning they can’t produce their own food. Instead, they are well-known bacterivores i.e. they consume bacteria to power themselves.

Plankton and their role in the food chain:

• The phytoplankton is found nearer the surface of many water bodies. It is an autotroph, which means it can make its own food which it does by consuming carbon dioxide, among other compounds, through photosynthesis. 
• Small fish and larger plankton called zooplankton eat phytoplankton for their nutrition; they are in turn eaten by larger fish, and so forth.
• When phytoplankton die, they drift around where they are, becoming part of a coastal nutrient cycle, or they drift down towards the seafloor, where they decompose. 
• Their constituents then become available for microbes or are sequestered into the seafloor.
• So, phytoplankton bring carbon and other nutrients from the atmosphere and sea surface down to the seafloor and help replenish the food chain (and also ‘trap’ carbon into their own bodies and as sediments). 
• They are joined by bacteria that make their own food by oxidising sulphur, iron or hydrogen, in a process called chemosynthesis.