The dragonfly
Mostly the dragonflies are brought into an aquarium by the purchase of new plants without being noticed. They have nested in greenhouses of aquarium plant gardening in the plant roots or they have laid down their eggs there. If there are dragonfly eggs at the plants the larves can also emerge according to the depositing of the eggs after 5 weeks in the aquarium.
Dragonfly larves are robbers and able to overwhelm fishes or shrimps that are larger than they are. To the mating season they even eat other dragonflies sometimes even members of the own type and thus they also show cannibalism.
In the water the larves are well adapted robbers and own a typical catch mask that is folded under the head in the rest state. This organ for rapacious is most effectively fitted to their way of life. If there is a potential victim within reach, this throat-reinforced instrument shoots out and the booty is packed.
Small dragonflies (Zygoptera) prefer for booty particularly gnat larves and small cancers like creek flea cancers and they even can catch booty like cancer- and shrimp junior stuff. Larves of the majority dragonflies (Anisoptera) chase correspondingly bigger booty animals like small tadpoles or young fishes and full-grown dwarf shrimps.
For the underwater respiration the dragonfly larves have two different techniques by which they are able to be distinguished at the first sight: The small dragonflies have three leaf-shaped gills at their rear end with which they can incorporate the oxygen of the water. On the other hand the majority dragonflies does not own visible gills, these are moved into the final intestine (rectal gills). The lift of the oxygen occurs in this case through a specific tissue in the final intestine.
The duration of the larve in the water sways considerable. According to the dragonfly type between 3 months ( Central Europe ) and 5 years (Source old maids, Cordukegaster). During the development of the larve the animals go through up to 10 larve stages.
If you discover a dragonfly larve in your aquarium you should try to catch it out of the water. This can be very difficult in a thick planted aquarium because the larves are able to move very quickly. Since the dragonflies are protected here you should put it into the next pond or slough as soon as you have removed it from the aquarium. |
