BOGOTÁ — Researchers in Colombia have discovered six new species of tardigrades — also known as "water bears' — a phylum of microorganisms considered the planet's most resilient for their physical and anatomical qualities.

The team, headed by Sigmer Quiroga Cárdenas of the University of Magdalena, believes the mechanisms tardigrades use to keep their cellular structure and DNA intact, in a dry state, are key to creating new conservation methods — for human organs, for example.

The six species are from the Sierra Nevada de Santa Marta, a mountainous area in northern Colombia. "Moss and lichen specimens were collected where the tardigrades were found," Quiroga adds. "The goal is to make micro-preparations for analysis by the experts and students in the MIKU," as the research group is known.

Tardigrade under a microscope — Photo: Peter von Bagh

The group named the new "water bear" species Bryodelphax kristenseni, Doryphoribius rosanae, Itaquascon pilatoi, Milnesium kogui, Minibiotus pentannulatus and Paramacrobiotus sagani.

Quiroga says the discovery will allow for further research, starting in Colombia, on the unique tolerance mechanisms of tardigrades. The new specimens are now part of the University of Magdalena's Center for Biological Collections, the country's largest such collection with some 7,000 tardigrades overall.

The remarkable resilience of "water bears' is of particular interest in fields such as drug-making, medicine and food engineering, Quiroga explains. "These aquatic organisms have the ability, when water is scarce, to enter a state of anhydrobiosis wherein they can resist highly extreme conditions of temperature, or radiation levels that would be lethal to other organisms," he says.

Recognized as the planet's most "indestructible" animals, the eight-legged tardigrades (meaning "slow steppers') can be as large as one or two millimeters and, as their name suggests, move at a snail's pace. In Colombia, MIKU researchers have been pioneers over the past decade in the study of tardigrades, and have done much to raise awareness about the importance of miniscule creatures not only to ecosystems, but as models illustrating tolerance mechanisms in extreme conditions.