In the midnight world of the deep, where sunlight cannot follow and pressure crushes steel, there lives a creature so strange, so elusive and so immense that it has earned a place in both science and legend.

It is the giant squid—the living ghost behind the Kraken myth.

Its very name, Architeuthis dux, sounds like a sea chant in Latin: ruler of the deep. For centuries, it was a nightmare sketched in fear and half-truths by sailors who glimpsed only its wreckage. 

The juvenile squid, approximately 30 centimeters  in length, was filmed on March 9, 2025, at a depth of 600 meters (1,968 feet) near the South Sandwich Islands in the South Atlantic Ocean.

This unprecedented observation was made possible by the remotely operated vehicle (ROV) SuBastian, which is capable of reaching depths up to 4,500 meters. The sighting coincides with the 100th anniversary of the species' formal identification. ​

The squid exhibited behaviours typical of brooding, where a female carries her eggs externally until they hatch. This adaptation is particularly fascinating in the deep-sea environment, characterized by darkness, low temperatures, and limited food availability. The eggs measured up to 11.2 millimeters in diameter, significantly larger than those typically associated with Gonatidae squids, which usually do not exceed 6 millimeters.

A review published in the journal Animal Sentience describes the surprising abilities found so far among octopus species.

Heat stress brought about by rising temperatures may cause impaired eyesight and more deaths of pregnant mothers and their unborn young. 

In a study by the University of Adelaide, unborn octopuses and their mothers were exposed to three different temperatures: a control temperature of 19°C, 22°C to mimic current summer temperatures, and 25°C to match projected summer temperatures in 2100.

Negative impact on eyesight

Compared to the other two groups, octopuses that were exposed to 25°C produced significantly fewer of some proteins responsible for vision. 

Scientists from the University of Tokyo have discovered that a male spear squid’s birthday is not just a date—rather, it determines their mating strategy for the rest of their lives. 

According to their study, spear squid that are born early in the mating season (between early April and mid-July) grow to formidable sizes. Called “consorts“, they actively fight off any rivals in order to mate and then stick close to their mate as she lays her eggs. 

Unlike any other member of its species, the mimic octopus excels in the art of disguise. It possesses the remarkable capability to alter its shape, hue, and behavior to resemble various marine organisms, including lionfish, flatfish, sea snakes, and more. This extraordinary talent serves not only as a spectacle but also as a survival strategy, aiding the octopus in confounding predators and capturing prey.

The deep, emerald waters surrounding Japan's Okinawa Islands are a haven for marine life, and is one of the most biodiverse ecosystems on the planet. Within this vast biodiverse haven, scientists have discovered two new species of pygmy squid lurking beneath the surface: the Ryukyuan Pygmy Squid and Hannan's Pygmy Squid.

These two species have now been described and catalogued, with names that connect them to Japan's cultural heritage. Findings have been published in the Marine Biology journal. 

The team, aboard the Schmidt Ocean Institute's research vessel Falkor, located the nursery nearly 2,800 meters below the ocean's surface. The expedition's footage, captured by the underwater robot ROV SuBastian, showcased breathtaking marine life, including octopus hatchlings, tripod fish, and vibrant coral gardens.

A recent study has unveiled a fascinating aspect of octopus biology: their ability to adapt to cold ocean temperatures by making precise edits to their RNA. 

RNA editing is a molecular process through which cells can modify nucleotide sequences in RNA, resulting in proteins that differ from those directly encoded by DNA. This ability is particularly enhanced in octopuses, who use it to fine-tune the functions of their nervous system at low temperatures.