Mono Lake in California is a hostile location for the majority of life forms similar to the Antarctic deserts or the deepest parts of the sea. Only saline shrimp and diving flies can adapt to its super-salty waters apart from bacteria and algae.
Recently, eight new species of the microscopic worm have been discovered in the lake by researchers from the California Institute of Technology and it turns out one of them is a bit different.
The team reported that Auanema sp. which is one of the newly-discovered species of nematode has three different sexes. It can also endure a dosage of arsenic 500 times more than the human limit.
Nematodes are usually classified into males and hermaphrodites but Auanema sp. also has female worms. Moreover, researchers have noticed other fascinating sex characteristics such as the arrangement of genital papillae in males of Auanema sp. in the genus. This microscopic worm also gives birth to their offspring, which is unique in the egg-laying nematode world.
Scientists think that the peculiar characteristics of the worm essential for it to remain alive in the extremely alkaline waters of Mono Lake. Thus its extreme features are not a coincidence. Pei-Yin Shih said these extremophiles can teach a lot about dealing with stress. Their study reveals the number of details left to learn about how these 1,000-celled animals have managed to survive in such conditions.
The researchers found a likewise high arsenic resistance among two sister species while comparing the strange new species of the nematode to others in the same genus. There lies another reason for this surprising tolerance because none of these creatures lived in environments with high arsenic levels.
The authors said that previous Auanema species were separated from rich soils and dung containing high phosphate concentrations. Also, it is possible that adaptation to high phosphate levels in the environment could lead to increased arsenic resistance since arsenic absorption occurs adventitiously via phosphate transporters. Nematodes might be pre-adapted to life being extremophile. Their genetic resiliency and flexibility make it easier for them to live in places like Mono Lake. Only two other species had been found which is three times saltier than sea with an alkaline pH greater than baking soda. Thus, the discovery of eight more species was not a surprise.
Nematodes are the most abundant animal on Earth thus having a high probability of even survive in Mono Lake.
Researchers from Caltech segregated nematodes from across the lake and found several niches over the period of two years in which these nematodes were prospering. They included microbe grazers, parasites, and predators.
The authors concluded that nematodes are the superior animals of Mono Lake in species richness. The phylogenetic study tells that the nematodes developed from several colonization incidents, which is remarkable, given the recent history of Mono Lake’s extreme conditions.
There are approximately 57 billion nematodes for every human on Earth so these creatures can start living in the most extreme places in no time. Tullis Onstott, geoscientist told that it’s good to find one more place with nematodes and nothing much else. These creatures might still be living in the places with absolutely nothing else.
Journal Reference: Current Biology