Because of their adaptive abilities — rapid growth, short lifespans and flexible development — cephalopods are sometimes called “the weeds of the sea.” And it seems like that might be serving them well.
According to study published in Current Biology cephalopod abundance has increased since the 1950s. The reason for this growth is not yet clear, but it maybe that their adaptability has allowed them to thrive in a changing climate while other ocean dwelling populations suffer. Study author Bronwyn Gillanders says that figuring out the reason for cephalopod abundance may tell us a lot about “how human activities are changing the ocean.”
At most sites around the Earth, nautiluses can be found at depths
between 300 and a thousand feet. They live singly (never in schools),
they grow slowly (taking up to 15 years to reach full size and
reproductive age), and they are never overly abundant as they slowly
swim over the deep sea beds searching for carrion on the bottom.
In all but one place on Earth, only a single nautilus species can be found at any one site.
Northeast of the main island of Papua New Guinea however, along the
coast of Manus Island, made famous by the American anthropologist
Margaret Mead in the earlier part of the twentieth century, not only can
you find the well-known chambered nautilus (Nautilus pompilius)…
south of Manus there is a second species as well.
It was first seen
alive in 1984, and was found to be so astoundingly different in shell
and soft part anatomy that it was, in 1997, give a wholly new genus
name: Allonautilusscrobiculatus. And then, for the next 30 years, it wasn’t seen again…
This cousin of the octopus has changed little in more than 150 million years. Its simple eyes can only sense dark and light, but the nautilus uses more than 90 tentacles—the most of any cephalopod—to touch and taste the world.