Everything about the mysterious giant squid Architeuthis dux is massive. It grows as big as a school bus, has eyes the size of dinner plates, and tentacles that can snatch prey from 30 feet away. This legendary beast of sea lore has frightened humans for ages, but how did it get so enormous in the first place? New research may soon offer answers, as the mighty cephalopod's genome was finally revealed Thursday.

"A genome is a first step for answering a lot of questions about the biology of these very weird animals," scientist Caroline Albertin said in a release from the University of Chicago. Those questions include how giant squids acquired the largest brain among the invertebrates, and how they became so agile and skillful.

Alphonse de Neuville/University of Chicago

"While cephalopods have many complex and elaborate features, they are thought to have evolved independently of the vertebrates," Albertin said in the release. "By comparing their genomes we can ask, 'Are cephalopods and vertebrates built the same way or are they built differently?'"

While the genome's revelation may answer some questions, in the immediate term it raises more. A key finding from the research shows how a giant squid's size-driving genes break with the patterns found among the important developmental genes in almost all other animals. This means the giant squid's enormity didn't come through whole-genome duplication, a strategy that evolution took long ago to increase the size of vertebrates.

It also means scientists have more work to do to get to the bottom of the giant squid's mysterious size.

Even so, Albertin said, having the giant squid genome is an important step in helping scientists understand what makes a cephalopod a cephalopod. It can also help scientists understand how new and novel genes arise in evolution and development.

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