Cosmos
Cosmos is a quarterly science magazine. We aim to inspire curiosity in ‘The Science of Everything’ and make the world of science accessible to everyone.
By Cosmos
Marine researchers have discovered in South America a new species of amphipod, which can live in water more than 50°C (122°F) – almost too hot to place a hand in, and certainly warm enough to cook them!
Amphipods are tiny shrimp-like crustaceans which usually have a segmented body, flattened at the sides. They have seven pairs of walking legs at front and three pairs of small limbs (pleopods) at the rear.
The new species, Hyalella yashmara, was discovered at Banos del Inca (Baths of the Inca) near the ancient city of Cajamarca, which is thought to have once been frequented by Inca rulers.
“We found that this new species can live in water temperatures ranging from 19.8 to 52.1°C, that, to our knowledge, is the highest recorded habitat temperature of amphipods,” say researchers in their paper published in the CSIRO Publishing peer reviewed journal Invertebrate Systematics.
They say H. yashmara, could potentially contribute to the understanding of the high temperature preference of these creatures.
“In recent years, the impact of rising water temperatures associated with global warming on cold-water freshwater organisms has become a major issue,” they write in the paper. “Therefore, understanding the physiological and ecological elements that support temperature limits is essential in the conservation biology of freshwater organisms.”
The copepod, Thermomesochra reducta, a plankton like species, lives in hot springs in Kuala Lumpur, Malaysia, in water temperatures between 38 and 58°C, and a variety of crustaceans have been reported in seafloor hydrothermal vents.
It’s thought that a common ancestor of H. yashmara and another amphipod, H. meinerti, invaded freshwater habitats when the continents of South America, Africa and Australia were united as Gondwana.
Although called freshwater shrimps, amphipods are not true shrimps. Typically, they dwell in cool aquatic and semi-aquatic habitats.
“The discovery of a new species from a previously unexpected high-temperature environment is most surprising,” study corresponding author Professor Ko Tomikawa, told Hiroshima University media.
The water temperature of the source of the hot spring was about 78°C, whereas that of the habitat of this new species ranged between 35 and 50°C. The pH value was 6.68. H. yashmara was not very active in the early morning when the water temperature was low (35–40°C) but was observed swimming during the day when the water temperature was higher.
“Many animals cannot tolerate high-temperature environments because proteins are thermally denatured at high temperatures. We guess the new species found in the hot spring of Peru has acquired a protein that is highly active at high temperatures, during the course of evolution,” Tomikawa explained.
The new species was given the scientific name Hyalella yashmara after the two daughters of one of the researchers.
These shrimp are unusual creatures
