Vampire Squid Have Strange and Unusual Sex Lives in the Deep Sea

Deep beneath the waves, strange and alien-like creatures haunt the depths of our ocean. One of them is the vampire squid, a cephalopod that lives at ocean depths from 500 to 3,000 meters. Now, scientists are learning a bit more about these unusual animals.

Vampire squid don't swim so much as float. They get by with little oxygen while also consuming a low-calorie diet of zooplankton and detritus, unlike their more-robust cousins at shallower temperatures. This isn't the only way that vampire squid differ, though. Scientists have found that they also differ in reproduction.

While other squid reproduce all at once late in their lives, vampire squid instead alternate between reproductive and resting phases, a pattern of multiple spawning more common among fish.

"Their slow mode of life seems insufficient to support one big reproductive event, unlike other coleoid cephalopods," said Henk-Jan Hoving, one of the researchers, in a news release. "Perhaps it is therefore that vampire squid return to a gonadal resting phase after spawning, and presumably start accumulating energy for a new reproductive cycle."

The researchers first discovered this mode of reproduction while going through vampire squid collections. They noticed that many of the females had spawned but had no ripe or developing eggs, which meant that they were in a reproductive resting phase.

So what does this mean? It likely means that vampire squid live far longer than shallow-water squid species typically do.

"We know very little about deep-sea organisms and their life-cycle patterns, in particular in the water column of the deep sea," said Hoving. "The patterns we know from coastal and shallow-water organisms may not apply to deep-sea species. We need to enhance our knowledge of deep-sea pelagic organisms and the system they are part [of] since the pelagic deep sea is the largest living space on the planet. A better understanding of this unique marine ecosystem will eventually allow for better development of management and conservation strategies."

The findings are published in the journal Current Biology.

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