The oceanic depths of the tenebrous ocean are not ideal for land-based creatures. The lack of light and oxygen creates crushing pressure.
This darkened part of the planet is alive with life; it has evolved to thrive under these conditions and looks very different from what you would find on drier shores.
For much of human history, most of this life was inaccessible. It has just been there, in the darkness, doing its job. The relatively recent inventions of remotely-operated underwater vehicles (ROVs), are finally opening our eyes towards this strange, dark, and silent world.
Schmidt Ocean Institute scientists onboard the ROV SuBastian, a research vessel, encountered a strange squid while flying the ROV Falkor. This genus lives in the ocean's lower mesopelagic or bathypelagic depths, up to 4,000m (13,123 ft) deep, just outside the reach of the Sun's radiations.
The Planctoteuthis, captured in rare footage (resurfaced by institute to celebrate its two-year anniversary), looks very different from what you would expect a squid looking like.
The tail is long and elegant with many appendages. Its arms are small. This individual has a tail decorated with blue streamers and cells called "iridophores" that sparkle as the squid moves through the water.
These iridophores consist of a series of very thin cells which can reflect different wavelengths of light. They reflect the light from the ROV's headlamps, glimmering golden. These cells are able to harness the light available in the dim environment where the squid lives. However, the purpose of this is not known. This could be used to attract prey or scare predators or to communicate with other squids.
This delicate, small genus of squid was discovered in samples taken from the depths. Planctoteuthis is rarely seen in its natural habitat, so we don't know much.
Scientists have discovered features that are only found in juvenile squids in these samples. This suggests that the genus may be slow to mature, or neotenic. We don't know why the tails are so long and elaborate.
It is possible that a creature may look different from its species if it doesn't look the same. This is known as mimicry and it can often be used to avoid predators in the animal kingdom. This Planctoteuthis may resemble a siphonophore. A siphonophore is a combination animal that has stinging cells and flashes light in order to attract prey.
Planctoteuthis may be using siphonophore appearance to attract prey similar to itself, and to repel predators that might be afraid of siphonophore stings.
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We will continue to learn more about these mysterious squids as we dive deeper into the ocean. Schmidt scientists captured a different species in 2014 on camera. Monterey Bay Aquarium Research Institute scientists were also able to capture a sighting last year.
Every expedition brings us rare sightings that reveal a little more about this beautiful, mysterious, and eerie world.