The mysterious vampire squids live much longer than cephalopods in shallow waters. Now researchers led by Henk-Jan Hoving of the GEOMAR Helmholtz Centre for Ocean Research have resolved the mystery of their longer life. In a study published in the journal Current Biology, researchers said that vampire squids have a unique and unusual reproductive strategy that helps them live longer.
Vampire squids spawn over 100 times
While other squids spawn all their eggs in one, high-energy burst, deep-sea squids that live about 10,000 feet below the ocean surface have multiple reproductive cycles. So, they live their entire life a little differently than shallow water squids, said Hoving. Scientists studied specimens of vampire squids from the Santa Barbara Museum of Natural History for their feeding and spawning habits.
They found that, unlike other squids, a female vampire squid can spawn more than 100 times in its lifetime. These squids experience alternating reproductive and resting phases. Scientists said that one of the fertile females they studied had laid more than 3,800 eggs over her lifetime, but still had viable 6,500 oocytes for producing more eggs.
Slow pace of life helps vampire squids live longer
For vampire squids, the pace of life is slower than that of shallow-water cephalopods, which grow very fast and have life spans of about two years. Hoving suggested that vampire squids have unusual reproductive cycles due to their slow metabolism. Instead of actively hunting for food, they depend on small particles of plankton. Vampire squids also consume fewer calories than their shallow-water counterparts.
Researchers believe vampire squids simply lack the energy to release all their fertile eggs in a single mating event. Their slow pace and longer reproductive cycles help them live longer. Notably, the vampire squid is not the only deep-sea cephalopod that lives longer than its shallow-water counterpart. In the past, researchers have found that a deep-sea octopus broods her eggs for four years, longer than most other octopuses can even live.