Aragon > Naturräume in Aragon > Fauna
Oligochaetes or worms are annelid worms, or ringed, with a cylindrical, soft body, elongated with numerous rings.
They are provided with ketas or silks (hence their name) that arise one by one of the muscles in a longitudinal direction.
They do not have parapods or "feet".
The head is reduced, without visual organs, and at its end is the mouth.
They have skin respiration.
There are almost 3,000 species, terrestrial and freshwater.
The worms are hermaphrodites but two animals fertilize each other, surrounding themselves with a mucous capsule and releasing both eggs and sperm.
The already formed larvae hatch from the eggs and do not metamorphose.
Earthworms feed on organic particles contained in the earth that they swallow and then expel into little piles of excrement.
They are very beneficial for agriculture, since they aerate the earth through the galleries that they excavate in humid soils.
They have a great power of regeneration.
There are species of 1 mm in length to others of more than 3 meters such as the Australian giant earthworm.
A small list of species in Aragon would be the following:
Vertebrates | Invertebrates |
---|---|
MammalsBirdsReptilesAmphibiansFishes |
MetazoansProtozoa |
images about the fauna in Aragon. photographs on invertebrates. beneficial animals for agriculture. |