Tardigrades, also known as water bears or moss piglets, are eight-legged microscopic animals known for their indestructible nature. Using cryptobiotic abilities they are able to dry themselves to crisp husks to survive extreme temperatures, pressure, and radiation, then come back to life when rehydrated.
So far 60 tardigrade species have been recorded in the harsh nature of the Antarctic. A new species has recently been discovered that lays eggs riddled with small spikes, which — strangely — vary in number, shape, and size.
Scientists on King George Island, off the coast of Antarctica, cataloged the new species of tardigrade by sequencing its DNA and measuring and describing its features, including its eggs. The new species is called Dactylobiotus ovimutans.
They wondered how and why D. ovimutans was able to alter the shape of its eggs. So they bred the tardigrades in lab, controlling temperature, light, and food. Other species of tardigrade occasionally lay differently-shaped eggs, and this has been tied to seasonality and environmental variation. The scientists expected that breeding the tardigrades in the lab might cause D. ovimutans to lay eggs that were similarly shaped.
But they found that the egg’s ornamentation continued to change in appearance. With no easy explanation, the scientists settled on another explanation to describe this phenomenon: epigenetics.
The question remains, why would D. ovimutans use important resources to change its egg’s appearance? What environmental factor is controlling this proposed epigenetic regulation? Many mysteries of the tardigrade and how it thrives in such harsh conditions still remain, including the discovery of these morphing, ornamental eggs.