Daphnid

The daphnids ( Daphnia ) are Crustacé S Phyllopode S Cladocère S from approximately 1 mm with 5mm.

Their popular name of “ chip of water ” gives an good idea of their size, their form and their way of evolving/moving in water.

They are used by the aquarist S like food for fish, but also to clean water.

Description

They have:

a squat body, protected by a transparent Carapace;
large antenna S feathery used for the stroke;
only one eye, but does they of them are two joined together eyes;
five tiny pairs of legs connected to the Thorax.

Manners

Habitat

The daphnids live in the stagnant fresh water points (pond S, Lac S, Mare S).

Food

The daphnids filter water and capture tiny organizations ic Plancton using a filter of mesh lower than the Micromètre, placed in entry of their digestive system (system similar to the Fanon of the Baleine S)

Locomotion

The daphnid moves while beating simultaneously of the two antennas. Its jerked stroke is worth the nickname of water chip to him.

Reproduction

The daphnid knows two modes of reproduction:

asexual reproduction by Parthenogenesis: this mode supposes favorable living conditions: what characterizes it, it is the absence of intervention of a male. The females, without fecundation, produce, every week, from 3 to 50 egg S which will hatch in the incubating pocket to give birth only to females.
reproduction sexuée with males: this type of reproduction intervenes when the living conditions are unfavourable: by parthenogenesis, the daphnids give rise to males and females. After Fecundation, two eggs of resistance are produced. Protected by a membrane, the eggs await the favorable conditions to hatch; they will give rise to two females.

Photographs of the 2 modes of reproduction of the daphnid

Others

the fish appreciate it because they facilitate to digestion especially red fish to them.
the daphnids are attracted by the light; to make shade with its hand with the top of water makes them flee and a flashlight the night attracts them.

Scientific use

In Toxicology of the environment - or ecotoxicology - the daphnids are usually used to study the Water quality and its capacity to allow the survival of the Zooplancton.

External bonds

http://georges.dolisi.free.fr/Aquario/Daphnie.htm

Random links: