A reader asked where one might be able to purchase small, tropical aquatic worms. Presumably this would exclude the giant tube worm, which lives near undersea volcanic vents and can grow to over seven feet in length. However, for the buyer interested in purchasing tropical aquatic worms of the smaller variety, a number of options abound, including flatworms (phylum Platyhelminthes), roundworms (Nematoda), segmented or “fan” worms (Annelida), and arrow worms (Chaetognatha).

If you saw a sign that said “worms for sale,” you might think you stumbled into an alternate reality. Worms for sale? How could that be? Who on earth would actually want to buy worms? Even if an advertisement promised “cheap worms for sale” or even “free worms,” you still may think it would be crazy to take someone up on this offer.