New Delhi: A team of researchers from Japan’s Okinawa Institute of Science and Technology Graduate University (OIST) has for the first time recorded squids changing colour to blend into their surroundings as a way of avoiding predators.
So far, octopus and cuttlefish were the only cephalopods — a group of marine animals characterised by their multiple arms and soft bodies — known to be able to camouflage by matching the colour of a substrate.
The research has paved the way for further studies into how squids see and perceive the world around them.
Squids usually hover in the open ocean. The team wanted to ascertain what happens when they move a bit closer to a coral reef or if they are chased by a predator to the ocean floor.
Squids are hard to keep in captivity, which is why this kind of research has been avoided so far. But since 2017, this team has been culturing a species of oval squid in captivity.
This type of squid, locally known as ‘Shiro-ika’, is one of three oval squids found in Okinawa. When in the open ocean, they are light in colour, meaning that they blend into the ocean surface and flickering sunlight above. But the researchers suspected that when they move closer to the ocean floor, it would be a different story entirely.
The camouflaging was accidentally observed by the researchers when they were cleaning their tank to remove algal growth. They noticed that the marine animals were changing colour depending on whether they were over the cleaned surface or the algae.
Following this observation, the researchers performed a controlled experiment. They kept several squids in a tank and cleaned half of the tank, leaving the other half covered in algae.
They placed an underwater camera inside the water and suspended a regular camera above, so they could capture and run statistical tests on any colour changes.
The team found that when the squids were on the clean side of the tank, they were of a light colour, but when they hovered above the algae, their colour turned darker.
The experiment uncovered an ability that had never previously been reported in squids. Read more.
Farthest astronomical object discovered
An international team of astronomers has discovered the most distant astronomical object ever — a galaxy located 13.5 billion light years away.
Named ‘HD1’, the galaxy was discovered by the team, which includes researchers from the Center for Astrophysics, an astrophysics research institute jointly operated by the Harvard College Observatory and Smithsonian Astrophysical Observatory.
The team has two ideas about the nature of the galaxy — one is that HD1 may be forming stars at an astounding rate and is possibly even home to the universe’s very first stars, which, until now, had never been observed. Second, HD1 may contain a supermassive black hole about 100 million times the mass of our sun.
HD1 is extremely bright in ultraviolet light. At first, the researchers assumed HD1 was a standard starburst galaxy, which is a galaxy creating stars at a high rate. But after calculating how many stars HD1 was producing, they said it was doing so at “an incredible rate”.
HD1 would be forming more than 100 stars every single year. This is at least 10 times higher than what we expect for these galaxies. Read more.
Fossil of dinosaur killed in asteroid strike found
In a first, scientists claim to have found fossils of creatures that were killed and entombed on the same day that a giant asteroid struck Earth and wiped out dinosaurs 66 million years ago.
The team found a dinosaur limb, complete with skin — which is just one of a series of remarkable finds emerging from the site in North Dakota, United States.
Very few dinosaur remains have been found in the rocks that record even the final few thousand years before the impact, which is why it would be extraordinary to have a specimen from the very day of the fateful impact.
Along with the leg, the team found fish that breathed in impact debris as it rained down from the sky.
They also found a fossil turtle that was skewered by a wooden stake, remains of small mammals and the burrows made by them, the skin of a horned triceratops, the embryo of a flying pterosaur inside its egg, and what could be a fragment of the asteroid impactor itself.
The findings from the site reveal unprecedented details about what happened that day.
Scientists now widely accept that a roughly 12 km-wide space rock hit the planet, causing the last mass extinction that wiped out dinosaurs.
The impact site has been identified in the Gulf of Mexico — some 3,000 kilometres away from the site in the US where the fossil was found. However, the energy imparted in the event was so large that its devastation was felt far and wide. Read more.
Ocean samples yield over 5,500 new RNA virus species
Samples collected from oceans around the world by an international team of researchers have yielded a treasure trove of new data about RNA (Ribonucleic acid) — with scientists identifying over 5,500 new RNA virus species.
The research reshapes the understanding of how these submicroscopic particles evolved.
The team used machine-learning analyses to identify over 5,500 new RNA virus species. These represent all five known RNA virus phyla, and the team suggest that at least five new RNA virus phyla now are needed to classify the species.
The most abundant collection of newly identified species belongs to a proposed phylum that researchers named Taraviricota, acknowledging the contribution of the 35,000 water samples by the Tara Oceans Consortium, an ongoing global study onboard the schooner Tara, of the impact of climate change on the world’s oceans.
While microbes are essential contributors to all life on the planet, viruses that infect or interact with them have a variety of influences on microbial functions. These types of viruses are believed to have three main functions — killing cells, changing how infected cells manage energy, and transferring genes from one host to another.
Knowing more about virus diversity and abundance in the world’s oceans will help explain marine microbes’ role in ocean adaptation to climate change. Read more.
Cache of pterosaur fossil unearthed in Atacama Desert
A team of scientists in Chile has unearthed a cache of well-preserved bones of ancient flying reptiles that roamed the Atacama Desert more than 100 million years ago.
The remains belong to pterosaurs — flying creatures that lived alongside dinosaurs. The team at the University of Chile has been searching for pterosaurs for years. Usually, pterosaur remains are found isolated.
The discovery may shed light on how pterosaurs behaved in groups.
Most pterosaur bones were found flattened and broken, but the team says that they were able to recover preserved three-dimensional bones from the site. This well help scientists better understand pterosaur anatomy.
The discovery also shows that pterosaurs were once widespread in northern Chile. Read more.
(Edited by Gitanjali Das)