The Age of Cephalopods (Again)

Ordovician(by mirelai from Deviant Art)

In a long-ago post, Ferrebeekeeper wrote about the Ordovician–the age of mollusks–when big predatory cephalopods and gastropods overtopped nascent vertebrates as the apex predators of the world oceans.  Cephalopods are fiercely intelligent, incredibly fast, and astonishing at camouflage.  They can be infinitesimally small or remarkably large.  They can even be transparent.  However they don’t last well—they are squishy and even if they aren’t eaten they have very short lives.  One of the most vivid memories of my adolescence was watching cuttlefish hover and change colors and feed with bullet-fast grabber arms at the National Zoo.  The memory comes with a dark post-script.  I returned a few months later with friends, only to find that the cuttlefish had entered a bizarre unnatural senescence and were literally falling apart at the seams.  They do not die of old age in the ocean; something always eats them.

But this is no longer the lovely Holocene with its oceans full of fish and skies full of birds.  We have entered the Anthropocene—an age of hot acid oceans filled with Japanese trawlers bent on catching every last fish in the sea by means of nets the size of Rhode Island.  Suddenly it is not so beneficial to be a big bony ancient fish with hard scales and sharp teeth.  The teleosts and the cartilaginous fish are being physically pulled out of the ocean by humans.  It takes them too long to reproduce and rebuild their numbers (even as national governments subsidize fishermen to build more and larger fishing boats).  The age of fish—which has lasted from the Devonian (420 million years ago) until now—is ending.  So a new scramble to exploit the great open niches in the seas is beginning.

Unexpected life forms are flourishing.  The sea floors are filling up with lobsters, which have not been so prevalent in a long time.  Giant jellyfish are appearing in never-before-seen numbers.  However it is beginning to seem like the greatest beneficiaries may be the cephalopods. Mollusks with shells are having their own troubles–as the carbonic acid oceans eat at their calcium shells, but the octopus, squid, and cuttlefish have no such problems.  Not only are they well suited for tropical waters, they rcan also reproduce so fast that they can keep ahead of human’s bottomless appetite.  A single squid egg cluster can have millions of eggs inside.

Cephalopods tend to be generalists—they eat all sorts of things including booming micro-invertebrates and jellyfish. They are clever enough and malleable enough to slip out of all sorts of hazards.  Their swift lives are a boon. Because they reproduce so quickly and prolifically, they evolve quickly too—a necessity in our 24 hour world (as all sorts of out-of-work journalists, lamp lighters, factory workers, and saddlemakers could tell you).  I wonder if in a few million years the waters will glow with great shoals of exotic tentacle beasts we have scarcely imagined.  Will there be fast marlin-type squids with rapiers on their mantles and huge whale-shark type octopuses skimming the phytoplankton with their own giant nets? Will the skies darken with flying squids and the sea floor change colors as tens of thousands of cuttlefish take the roles of reef fish and reef alike?

Hawaiian bobtail squid (image from forums.furcadia.com)

It is possible.  The world is changing faster than we would like to admit—becoming something brand new—becoming something very old.

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