The most common vertebrate is probably not what you’d think

There are approximately 7.6 billion people on earth.1

Somewhere between 19 to 24 billion chickens.2,3

But what is the most common vertebrate species on the planet? And how many of them are there?

The answer, it turns out, is the humble bristlemouth fish (Latin family name Gonostomatidae), and it numbers in the Hundreds. Of. Trillions. (And possibly, according to some estimates, in the quadrillions.)4 An unassuming family of fishes, the bristlemouths range in size from 1 to 11 inches5 and prefer the mid-ocean depths of about 0.5 to 1 mile down.6

You can read more about the bristlemouth fish in this fascinating expose!

Gonostoma bathyphilum
Gonostoma bathyphilum (Photo credit: Wikipedia)

(For the record: if you’re wondering what the most abundant animal of any kind is, it’s not an insect — it’s the nematode, which apparently accounts for 4 out of every 5 living creatures on earth.7)


Massive superpods of dolphins sighted near South Africa

Bottlenose dolphins are social animals. Just as wolves live in packs, dolphins live in pods of generally 10-30 individuals (although groups of 50 or even 60 are not uncommon1). Researchers studying Indo-Pacific bottlenose dolphins, however, have been documenting substantial increases in pod sizes off the coast of South Africa. From 2008 to 2016, pod size in the area increased from an average of 18 animals per group to an average of 76.2  On top of this, some of the largest pods ever reported have been observed in the area — with sightings of as many as 600 dolphins in a single group.

Scientists are unsure as to what might be causing pod size to swell. According to research published in Marine Mammal Science,

“neither season nor behavior had a significant effect on mean group size at both sites. Similarly environmental variables such as the depth and substrate type also had no influence on group size. It remains unclear which ecological drivers, such as predation risk and food availability, are leading to the large groups observed in this area, and further research on abundance and distribution of both predators and prey is necessary.”

Check out some video footage of a superpod, below: