Symptoms: scales are sometimes swells, it forms a swelling, sometimes bleeding, is darkening of the gills. The behavior of the fish are restless.
Cause: the maximum allowable values of oxygen in the water, which in the blood vessels of fish, released in the form of bubbles and thereby clog blood vessels, protrudes under the skin in the form of bubbles.
The increase of oxygen in the water may occur when replacing the water, (not pooled water), if excessive evolution of oxygen by plants in photosynthesis.
Treatment: to create a blackout in the aquarium, turn off the compressor, to lower the oxygen content in the water by replacing the old pooled water.
Symptoms: fish are anxious, to swim at the water surface, Gill filaments pale and covered with mucus. With the lack of action, fish are dying.
Reason: exceeded the maximum allowable concentration of chlorine in the water, i.e. 0.05 mg/l or more.
Treatment: replace water with appropriate indicators for this type of fish. Continue reading
Feeding fish often estimate the so-called feed ratio showing the amount of feed (in kg), should eat fish to give 1 kg of gain.
For example, if they say that feed efficiency of sunflower meal is $ 4, this means that in order for the fish increased weight by 1 kg, she had to eat 4 kg of this cake.
In other words, feed coefficient expresses the ratio of eaten to increase.
Sometimes to determine the effectiveness of feeding favour by not feeding ratio, and the so-called forage payment, or, in other words, the feed consumption per unit growth of fish.
This indicator expresses the ratio between the amount specified (and not eaten, as in determining the feed ratio) in the feed pond to increase fish.
The latest from economic point of view is more correct .
Payment of feed cannot be identified with the ratio of forage, as is sometimes done .
Indicators feed ratio will always be lower than the payment of food, not all food as defined in a pond, eaten by fish, some feed (due to various reasons) always lost.
Total feed ratio and payment of the feed, the lower their performance, the greater the effect of feeding, i.e. feed between the index (and the payment of feed) feed efficiency observed inverse relationship. Continue reading
Red sea (Arab. البحر الأحمر Bahr el-Ahmar, Hebr. ים סוף Yam Suf, FR. mer Rouge) — inland sea of the Indian ocean situated between the Arabian Peninsula and Africa in a tectonic depression. In the North sea adjacent to the Suez isthmus that divides two bays: the Suez and Aqaba, via the Suez canal connects with the Mediterranean sea and the Arabian sea to the South connects the Bab-El-Mandeb Strait (“Gate of tears”) from the Gulf of Aden. Red sea — the saltiest of sea included in the World ocean.
The red sea washes the shores of Asia and Africa: Egypt, Sudan, Djibouti, Eritrea, Saudi Arabia, Yemen, Israel and Jordan.
The area of the red sea is 450 thousand km2. almost 2/3 of the sea lie in the tropical zone.
Water volume — 251 thousand km3.
According to various estimates, the length of C. J. miles from 1932 to 2350 km, width from 305 to 360. The coast is indented slightly, their outlines mostly predefined fault tectonics and almost the entire Eastern and Western shores parallel to each other.
In the bottom topography are highlighted in the coastal shallow (to depths of 200 m), the widest in the southern part of the sea, with numerous coral Islands and indigenous, so-called main trough, a narrow basin, which occupies most of the bottom of the sea to an average depth of 1000 m, and sevastra — a narrow and deep trench, as if embedded in the main trough, with a maximum depth, according to different sources, from 2604 to 3040 meters. And an average depth of 437 m. Continue reading