A 46-meter-long siphonophore found by scientists during an expedition into the deep waters off Australia's western coast may be the longest creature even seen. /VCG

The siphonophore, about twice as long as a typical blue whale, was spotted in March during an expedition into underwater canyons of Western Australia, led by the U.S.-based Schmidt Ocean Institute. /VCG

"Seeing this gigantic siphonophore when 'commuting' to the surface was an amazing sight. Like a giant UFO," said Nerida Wilson, a senior research scientist at the Western Australian Museum. The research vessel dived to depths of over 4,400 meters. The creature was discovered when it made its way back to the surface. /VCG

Siphonophores are deep-sea predatory carnivores made up of many individual zooids that work together to create a functional string-like body. /VCG