Coarse fish reach or lowland course zone, Biology

Coarse fish reach or lowland course zone

This zone corresponds to the lower course of the river. Here the river is deep and slow moving. Its sluggish flow results in the deposition of silt forming muddy bottom on which many hydrophytes can-grow. In this zone compared to other zones, the oxygen content is less and the temperature is more variable. Although some of the fish, characteristic of the upper reaches of the river may be present in this zone, but conditions here are not suitable for them to complete their life cycle successfully. For example, salmon and trout require silt-free gravel in which to lay their eggs and cold, well oxygenated water for their young offspring.

Conditions are now more suitable for other fish species such as cyprinids, the roach, the chub and the bream. These fishes can tolerate low concentration of dissolved oxygen and higher water temperature and need water plants on which they can lay their eggs. In the lowest reaches of a river running into an estuary the sea occurs to flow under, during the summer months.

Posted Date: 1/19/2013 5:17:34 AM | Location : United States







Related Discussions:- Coarse fish reach or lowland course zone, Assignment Help, Ask Question on Coarse fish reach or lowland course zone, Get Answer, Expert's Help, Coarse fish reach or lowland course zone Discussions

Write discussion on Coarse fish reach or lowland course zone
Your posts are moderated
Related Questions
Explain the Future challenges for Neuroscience? When the analysis of single cells and even networks has progressed very nicely, there still remain many significant questions. A

Q. What is the osseous cavity where the pituitary gland is located? The hypophysis or pituitary gland is located in the sella turcica of the sphenoid bone (one of the bones in

How are the bacteria and the archaea different from all the other cellular microbes? -They have cell walls? -They can move? -They reproduce asexually? -They have no nucleus?

The permissible use of the technique amniocentesis is for: 1. detecting sex of the unborn foetus 2. artificial insemination 3. transfer of embryo into the uterus of the su

Radiographic Evaluation An intraoral periapical radiograph with a paralleling technique should be made and observed to ensure absence of pathology in the peri-implant region an

Explain cardiac examination auscultation and its techniques? Auscultation of the heart sound and associatcd sound is very important to diagnose the cardiovascular diseases. It

Explain the Metabolism - Zinc? Zinc has been found to play an important biological role in our body. Zinc ions can be chelated and precipitated by a number of chelating agents

Which of the following is true for endocytosis? A. During endocytosis of GLUT4 transporters in fat cells, there is removal of GLUT4 transporters from plasma membranes. B. Du

Nursing Process History Character of onset and duration of cough, sputum production, dyspnea, pain in right upper quarant.  Smoking history.  Past illness -

Acyanotic Congenital Heart Disease   In this infant has no cyanosis because there is no abnormal communication between pulmonary and systemic circulation or there  is no mixing