what are different types of feed 11 class fishery
Answers
Answer:
In general, carnivorous fish, juvenile fish, and fry will require a higher protein content. Processed feed can be delivered in many different shapes and sizes as well. The main types of processed fish feed are pellet food, flake food, and powdered food.
Answer:
This is the answer
Explanation:
10.0 Introduction
1. In Section 2.0 of this manual, you have learned that plants are able, through photosynthesis, to utilize sunlight and simple nutrients to produce new organic material. On the contrary, animals, including fish, cannot. Thus to survive, grow and reproduce, fish need to feed on organic materials such as plants, other animals, or prepared feeds containing plant and/or animal material. It is therefore most important for you to ensure that your fish get the food they require, both in quality and in quantity.
Selecting fish foods
2. There are three types of food used in fish ponds:
natural food;
supplementary feeds;
complete feeds.
3. Natural food is found naturally in the pond. It may include detritus*, bacteria*, plankton*, worms, insects, snails, aquatic plants and fish. Their abundance greatly depends on water quality. Liming (see Chapter 5) and fertilization (Chapter 6), in particular organic fertilization, can help you to provide a good supply of natural food to your fish.
4. Supplementary feeds are feeds regularly distributed to the fish in the pond. They usually consist of cheap materials locally available such as terrestrial plants, kitchen wastes or agricultural by-products.
5. Complete feeds may also be regularly distributed. They are made from a mixture of carefully selected ingredients to provide all the nutrients necessary for the fish to grow well. They must be made in a form which the fish find easy to eat and digest. These feeds are quite difficult to make on the farm and are usually quite expensive to buy.
6. The system of production can be defined according to the type of food given to the fish:
extensive: fish production depends entirely on natural food;
semi-intensive: fish production depends on both natural food and supplementary feed; more fish may be reared in the pond;
intensive: fish production depends entirely on complete feed, and the stocking rate no longer depends on food availability but on other factors such as water quality.
7. In the following sections, you will learn more about natural food (Section 10.1) and supplementary feeds (Sections 10.2 to 10.6). If you are interested in complete feeds, you should read another FAO manual entitled Feed and feeding of fish and shrimp: a manual on the preparation and presentation of compound feeds for shrimp and fish in aquaculture, by M.B. New (Rome, FAO, ADCP Report 87/26, 275 pp., 1987).
117a.GIF (38459 byte)
10.1 Natural foods for fish
There are several kinds of natural foods
1. Natural fish foods present in a fish pond are very diverse and usually consist of a complex mixture of plants and animals.
(a) They range from microscopic to relatively large size.
(b) They may be alive or dead (detritus) and available from bacterial decomposition.
(c) They are generally present in various parts of the pond:
near the shore such as rooted high plants;
floating in the water such as plankton;
on the surface of or within the bottom (benthic material or benthos*) such as worms, insect larvae and snails;
covering the surface of submerged objects (biological cover or autwuchs*);
swimming around such as aquatic insects, frogs and fish (nekton*).
2. To help you manage your pond through fertilization (see Chapter 6), you should learn to recognize the most important groups of natural fish foods. For this you will need a simple microscope (see also Section 15.3), which you might be able to find in a local health centre, school or in a fish-fry production centre. Ask your extension agent for advice. Look at the following pictures remember that some of these organisms can be very small and practically invisible to the naked eye.
Note: 1 micrometre (micron)= 1�m = 0.001 mm.
Phytoplankton
Zooplankton
Which natural food do fish prefer
3. The food preferred by fish varies considerably, depending on species and development stage.
4. As you have already learned, fish larvae do not actively feed but survive on reserve food in their yolk sac (see Section 9.4). A short time before the yolk sac is absorbed, early fry start eating natural foods, which usually consist first of the smallest plankton such as microscopic algae and rotifers. As their mouth size increases, the fry eat increasingly larger plankton (cladoceres/copepods) and insect larvae/pupae. Little by little, as the fry grow older, food preferences change to resemble more and more those of adult fish.
First month of feeding for common carp