The Manta aliens were a species of sentient beings native to the Pegasus galaxy. Several of the beings were discovered on a barren planet, named Radek Colubia by Radek Zelenka, which was extremely hot and in the same system as New Lantea.
The creature was adapted to live in an extremely hot environment. The creature was thought to live in flocks of hundreds. The creature could emit strong EM pulses that can create energy shock waves. The creature was an intelligent life form that uses a radio frequency to communicate. The body consists of flesh and blood, and a single Manta is larger than Atlantis. Radek Zelenka speculates that one of them can cut the Apollo in half with a flap of its wings. When they go to their death process they dive into the corona sphere of a star to absorb its energy, by flattening their wings so that they are only a few molecules thick and link with each other to form a dark mass.
The creature flies into a star to absorb its energy to die and then be reborn again. The transformation emits some radiation, but not a fatal dose to a standard Human. The species had a peaceful way of life and needed four hundred solar rotations before it had completed its rebirth process.
As such, when the aliens performed this process shortly after Atlantis arrived on New Lantea, and because Atlantis wouldn´t survive that long without sunlight, Zelenka fired some Planet Busters into the corona sphere, which would have been strong enough to destroy a planet, but the Mantas absorbed the radiation, "drinking it like nectar" as Zelenka described it, allowing them to ascend instantly.
In 2008 the Atlantis Expedition discovered the Mantas when they explored the New Lantea's star system to learn more about it and find out if there were other life forms on them other planets in the system. Radek Zelenka was on board the Apollo and experienced two encounters with the creatures, both of which damaged the ship due to the creature's energy shock waves.
While the beings gathered energy from the solar system, their actions caused an eclipse which blocked sunlight from reaching New Lantea, causing the temperature to fall and the seas begin to freeze into ice. Within 24 hours, Atlantis would have been covered with ice and uninhabitable. Helen Sharpe wanted to use nuclear weapons on the creatures to kill them, but Radek stopped her to make contact with the creature with regular radio signals. The creatures had learned their language by listening to the conversation between Radek and Charp when he was in space in a space suit. Zelenka thus used nuclear weapons to increase ascension process for the creatures. The process was successful and the creatures were transformed from mortal to ascended beings of pure energy. (SGA: "Zero Point")