Polychaetes - (‘poly’ = many, ‘chaeta’ = bristle) worms

Why are they important to people?

How aren’t they important!!  Take a sample of the seafloor just about anywhere on the planet (remember, over 2/3 of the planet is ocean) and you will likely find polychaetes living there ranging in size from over four metres to individuals living between individual sand grains less than 0.1 mm long!

Most species have been found in the ocean, but they exist in estuaries, lakes, and rivers too. They are incredibly diverse and often comprise over 50% of the animal species found in any sea bottom sample.  It's not unusual to find more than 20 000 polychaetes living in a square metre of sand. 

They contribute a huge amount of food to important seafood species like flatfish, skates, really just about any demersal or benthic larval fish (fish living on or near the seabed). All that is only a tiny fraction of their job recycling nutrients between the sea floor and the water column.  They constantly rework the sea bottom and stabilise sediments with their tubes.  Some worms tubes are dense enough to form reefs which can shelter many other animals and even offer protection from hurricanes! 

Scientists are curious about the variety of ways worms (which share the same basic body plan) have evolved to live in so many different habitats and niches.  Some geneticists even use polychaetes to understand stages of HUMAN development! Like the famous lab fruit fly Drosophila melanogaster, several polychaete species are very important lab animals.

In short, polychaetes are one of the most important animals that keep aquatic ecosystems working! Indirectly, they provide a huge number of services to people worth billions of dollars. They feed us, recycle for us, they teach us about the world and ourselves, and they keep those beautiful coasts, estuaries, and rivers pretty and productive for us! Have you appreciated worms today?

"Worms have played a more important part in the history of the world than most persons would at first suppose." - Charles Darwin, 1898