Illustrated above is a deep-water marine fish belonging to the family Gonostomatidae. More commonly known as bristlemouths, Gonostomatidae are easily the most plentiful vertebrates on on the planet. How many are we talking? Have a guess; I bet you’ll underestimate. (I certainly did.)

Here’s William J. Broad, writing on the bristlemouth last week for The New York Times:

Though the portrait of the bristlemouth is incomplete, scientists know enough to confidently assert that it far outstrips all other contenders for the title of most common vertebrate on the planet.

Noah Strycker, the author of “The Thing With Feathers,” a book about birds, recently told an interviewer that the domestic chicken “has more numbers” than any other vertebrate.

He put the planetary figure at 24 billion.

In contrast, ichthyologists put the likely figure for bristlemouths at hundreds of trillions — and perhaps quadrillions, or thousands of trillions.

“No other animal gets close,” said Peter C. Davison, a fish scientist at the Farallon Institute for Advanced Ecosystem Research, in Petaluma, Calif. “There are as many as a dozen per square meter of ocean.”

It strikes me that bristlemouth numbers seem an effective way of communicating the profundity of the sea, itself. (Where are you ever gonna find space for thousands of trillions of fish? Why, the ocean, of course!)

Much more on the history and mystery of this “really unfishlike” fish at NYT.


Contact the author at Top image from Oceanic Ichthyology by G. Brown Goode and Tarleton H. Bean, published 1896, via.