Context:
Detailed 3D images of the first tardigrade fossils ever discovered help scientists predict when tardigrades evolved their near-indestructibility, which helps them survive in extreme environments.
Relevance:
Facts for Prelims
Overview of Tardigrades
Tardigrades, commonly known as water bears or moss piglets, are minuscule, eight-legged creatures that belong to the Tardigrada phylum. Globally, there are approximately 1,300 identified species of tardigrades. They are renowned for their ability to thrive in extreme environments and are considered extremophiles.
Habitat and Lifestyle:
- Tardigrades are primarily aquatic, necessitating a thin moisture layer around them to avoid dehydration. However, their remarkable adaptability allows them to inhabit diverse environments, from ocean depths to sandy deserts.
- Their typical habitats include freshwater mosses and lichens, which explains their alternative name, moss piglet.
Survival Capabilities:
- Tardigrades exhibit extraordinary resilience across extreme conditions, including intense heat, freezing temperatures, exposure to ultraviolet radiation, and even the vacuum of space.
- In adverse environments, they can enter a tun state, a form of suspended animation where their bodies dehydrate and curl into a dormant, seed-like form, allowing them to endure for extended periods, sometimes spanning years or decades.
Physical Characteristics:
- These creatures are compact and stout, covered with a tough cuticle similar to that seen in grasshoppers and other insects, which they must periodically molt to grow.
- Typically measuring around 1 mm or less, tardigrades possess no skeletal structure but are supported internally by a hydrostatic skeleton, which is essentially a fluid-filled compartment known as a hemolymph.
- They feature four pairs of legs, each ending in 4 to 6 claws, adept for navigating their microenvironments.
-Source: Indian Express
