You may have missed… deepest dwelling fish, world’s smallest wineglass, microscopic worms use electricity to jump, and black hole echo.

Your hit of the best of last week’s science.

How the deepest dwelling fish survives in the Mariana Trench

Genetic analysis of the hadal snailfish (Pseudoliparis swirei), the deepest dwelling known vertebrate species, have revealed key adaptations that allow it to survive more than 6,000 metres under the ocean.

The results, published in eLife, suggest that having multiple copies of two genes, cldnj and fthl27, allows the hadal snailfish to maintain their auditory senses and withstand the immense pressure they are subjected to underwater.

Hadal snailfish have three copies of a gene, cldnj, essential for the formation of otoliths – a structure in the inner ear made of calcium carbonate. Typically, calcium carbonate cannot efficiently accumulate to form otoliths beyond about 4,000 metres underwater, but not for hadal snailfish!

They also have 14 copies of the gene that encodes the protein ferritin, fthl27, which significantly increases tolerance to reactive oxygen species that are responsible for the damage caused by high hydrostatic pressure. 

3D printing the world’s smallest wineglass

Researchers have 3D-printed the world’s smallest wine glass, with a rim smaller than the width of a human hair. The results, published in Nature Communications, demonstrate a new simplified technique for creating silica glass structures for applications such as telecommunications and robotics.

The study’s lead author, Po-Han Huang, a doctoral student at The KTH Royal Institute of Technology, Sweden, says this new method drastically reduces the energy needed to 3D print silica glass. Usually, it requires heating materials up to several hundred degrees for hours.

“The advantage of our method is there’s no need for thermal treatment and the glass can withstand extreme heat in applications,” he says.

“The backbone of the internet is based on optical fibres made of glass. In those systems, all kinds of filters and couplers are needed that can now be 3D printed by our technique,” adds co-author Kristinn Gylfason, an associate professor of Micro- and Nanosystems at KTH.

Microscopic worms use electric fields to jump

Microscopic Caenorhabditis elegans worms can use electric fields to “jump” across petri plates or onto insects, according to a new paper in the journal Current Biology.

“Pollinators, such as insects and hummingbirds, are known to be electrically charged, and it is believed that pollen is attracted by the electric field formed by the pollinator and the plant,” says Takuma Sugi, a biophysics professor at Hiroshima University, Japan, and co-senior author on the study.

“However, it was not completely clear whether electric fields are utilised for interactions between different terrestrial animals.”

The research team began their investigation when they noticed that worms they cultivated in petri dishes often ended up on the lids. Using a camera to observe the behaviour revealed that the worms weren’t climbing up the walls of the dish and were instead leaping from the floor of the plate to the ceiling.

“Worms stand on their tail to reduce the surface energy between their body and the substrate, thus making it easier for themselves to attach to other passing objects,” Sugi says.

“In a column, one worm lifts multiple worms, and this worm takes off to transfer across the electric field while carrying all the column worms.”

Researchers rubbed flower pollen on a bumblebee so that it could exhibit a natural electric charge. Once close to these bees, worms stood on their tails, then jumped aboard. Some worms even piled on top of each other and jumped in a single column, transferring 80 worms at once across the gap. Credit: Current Biology/Chiba et al.

Echo emitted by our Galaxy’s black hole 200 years ago detected

An international team of scientists has discovered that Sagittarius A* (Sgr A*), the supermassive black hole at the centre of the Milky Way, emerged from a long period of dormancy about 200 years ago.

They found that, at the beginning of the 19^th century, the black hole devoured cosmic gas and dust – going through an intense period of activity before becoming dormant again.

Using NASA’s IXPE (Imaging X-ray Polarimetry Explorer) satellite, researchers detected the polarisation of an X-ray echo emitted from the event, which was reflected off of dense gas in the Galactic Center region. The emission was at least a million times greater in intensity than that currently being emitted by Sgr A*.

They are continuing their work on Sgr A* to try to determine the physical mechanisms required for a black hole to switch from a quiescent state to an active one.

The research is published in Nature.