Poate stii engleza, in schimb
Rudder foot cancers, Huepferlinge, Copepoda
Most rudder foot cancers occur in the sea. Only about 125 kinds live in the fresh water.
The sizes vary between approx.. 500 µm and 2.5 mm. The kinds are difficult to determine. According to the length of the antennas and number of its members one differentiates three groups:
1. Calanoida: First antennas very long with up to 25 members. Only first right antenna of the males with grab organ. As floating Plankter they nourish themselves strudelnd of bacteria and microscopically small algae.
2. Cyclopoida: First antennas with 8 to 17 members. Both first antennas of the males with grab organs. They occur in small waters and nourish themselves as robbers in addition, of carrion and algae.
2. Harpacticoida: First antennas with at the most 8 members. Both first antennas of the males with grab organs. They are to be found predominant bad floats and therefore in the substrate.
For the reproduction of the rudder foot cancers see Naupliuslarve
Calanoida, female Calanoida, male
Calanoida are good at their long to recognize to 25gliedrigen first antennas. The length of the antenna is nearly body-long, the body of this kind approx.. 2,2 mm.
With the male the catch organ is to be recognized by the first right antenna.
The antennas are not primarily of sensory organs with sense bristles and sense pistons, progressive movement organs. Before each hopping Fortbe
wegung they are set on the body and immediately spread afterwards again
The Furca branches, which are to be seen good with the males, are often covered of the Eipaketen with the females.
Picture right down shows the last Thorakelsegment with the Furca branches and the bristles. Form of the Thorakel of segment and the Furca branches, as well as number of bristles are relevant for the determination of the kinds.
A stronger color is to be recognized with rudder foot cancers - regarded with the naked eye - hardly. They are normally cloudily white or greenish with strongly algenhaltigem water also sometimes easily. Only with view by the microscope one recognizes that the transparent kinds gleam light blue to lightgreen and are noticeable in the inner body blue, yellow, orangene or red marks, which are caused by stored oil drops. These support, through
Lower the specific weight, the abilityability ability.
, one can not see as bright colors as with the lower picture normally naturally. They are caused only by the birefringence with polarized light at the external skeleton from chitin with view in the microscope with polarisation filters.
Cyclopoida, before it a Naupliuslarve Cyclopoida with less than 17 members with
1. Pair of antennas
(C)
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