© DAVID PAUL
The deep sea-dwelling giant squid Arciteuthis has turned up all over the world. But, whether in Florida or Japan, the invertebrates are all members of the same species, according to a paper published today (March 20) in Proceedings of the Royal Society B. Analyses of 43 squid from diverse locations showed that their mitochondrial DNA varies surprisingly little.
This lack of genetic diversity is puzzling. While giant squid are elusive, the researchers wrote, their populations are believed to be relatively large and geographically spread out—qualities usually associated with high diversity. The first live giant squid was spotted in 2004, and the Discovery Channel published the first video of the species earlier this year. But partially digested fragments of the cephalopods are found frequently in the ...