Earthworms are some of the world’s most useful creatures. But, little is known about them.
In Iceland, about 50 scientists recently gathered to discuss the 12 species of earthworms found on this northern island.
The specialists, who met in Akureyri in the north of the country, came from several Nordic and Baltic countries.
They were actually discussing more species than just earthworms, because, as biologist Bjarni E. Gudleifsson told a reporter at the Icelandic newspaper Fréttabladid, it’s not unlikely species of tiny beings exist in Iceland that do not exist in other places.
Though this is likely true of the whole Arctic, this is especially true for Iceland, due to the island’s isolation from the rest of the world, as well as the fact it is volcanic ground.
Fewer animals exist in Iceland than in other circumpolar countries.
“For example, here we only have 11 types of earthworms, whereas in other Nordic countries, we have several dozens; spiders are fewer than 100, and most of them are very small,” said Gudleifsson.
In particular, the scientists discussed their findings of the effects of tillage and other human enterprises, including grass fire, power plants, radiation and pollution.
“Most insects live in the topmost five centimetres of the earth, which is why much can effect them,” said Gudleifsson.
“In my studies of field cultivation, I have discovered that this practice lessens the number of insects in the dirt, but at the same time has the effect within some species that their numbers go drastically up.”
Earthworms are rather interesting beings.
Though only 11 are found in Iceland, more than 3,000 have been discovered worldwide, according to biologist Hólmfrídur Sigurdardóttir.
They are hermaphroditic, which means they are both male and female at the same time – which undeniably can come in handy.
When they mate, they only exchange sperm, so hopefully both worms go away pregnant after their meeting, which can last up to four hours.
At the bottom of their front end, there is a toothless mouth covered by a soft piece of skin. On that lobe, most of the worm’s sensory organs are located, as well as in its mouth and throat.
Their nervous system is very primitive, so it’s unlikely that they experience pain like anglers do, according to Sigurdardóttir, who says they only live three years, at the most.
They are extremely important to the life cycle, particularly in the North where fewer beetles and insects exist, because they eat their way through the earth, creating air holes that allow water to filtre through the dirt.
They also mix the material in the dirt by eating rotting leaves on top of the ground and moving them further down into the ground.
When it rains, the earthworms come to the surface, not because they’re drowning, but in search of a new place to live, a spouse or simple adventures, said Sigurdardóttir.
Many people the world over know the tale that if you cut an earthworm in half, both parts will live.
But this is only partly true.
Sigurdardóttir said that the main rule is that if the front end is sufficiently long, it can grow a new hind part.
But the hind part itself will not live for long after its mouth and sensory organs are severed.