Introduction :
The introduction to some crustacean species has produced alternation of Fresh water environments and declines of native species world wide. The red swap cry fish, procamberous clarkii, Girardi, was introduced south west.
Iberian penninsala in the "1970" producing serves impact on rice agriculture & no native biota such as microphyte, gastropodes , gastrophytes.
Microphytes:
An aquatic plant or microscopic algae that are invisible to be seen by nacked eyes.
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| Fig- microphytic algae under microscope. |
Gastropods:
A soft body animal and usually a shell that can live either In land or in water. Commonly known as snail, slugs. Belongs to a large taxonomic class of invertebrates with in the phylum molluscs, called "gastropodes".
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| Fig- Gastropods. |
Native cry fish and amphibian: We study the distribution of p. clarkii in two areas of south west ebirian peninsula: the sado river basin [south west Portuguese] an area of colonies by the species around "1990" and the parque natural del entoma.
1.Lotic Habitat: (lotic = flowing water).
A lotic ecosystem as flowing water.
Eg. River, Spring, Cricks, River stream, Brooks, and channels.
*Life long lotic system:
Fig: Life long lotic system
*Habitat with stream:
1. A body of water which has a continues flow of water, obtain refer to has cricks or brooks
2. Loti refer flowing water, lotic ecosystem can be contracted with lentic ecosystem, which involve still terrestrial water such as a lacks, ponds, together this to filled from the more general study area of fresh water or aquatic ecology.
2.Lentic habitat: (swamp water, stagnant)
*Characteristics:
1. Water temperature from top to bottom is usually the same.
2. Water dozen stay put for very long.
*Lotic habitat spring:
Kind of a fresh water habitat were water flows out of the ground.
*Lentic Habitat:
Lentic ecosystem are characterized by still water.
Eg: Lakes, ponds, basin marshes, reservoir etc.
*Thermal stratification in lakes:
Lake stratification is the tendency of lakes to form separated and distinct thermal layer during the summer weather. There are 3-types of Thermal stratification. In the separation of lakes into 3-layer.
1.Epilimnion.(Warm water):
The top of the layer.
2.Thermocline:
Middle of layer, which may changed depth though out the day.
3.Hypolimnion:
The bottom layer.
