Immediate disposal of farm products in perfect condition adds to the overall farm income and reputation. Fry, fingerlings and table size fish are the main products of undrainable ponds which require different ways and means of disposal. Table-size fish after harvesting need immediate transportation so that it may reach the destination in fresh condition whereas fry and fingerlings are to be transported in live condition.
Fish perish more quickly than chicken, beef, pork, etc., and the spoilage is mainly due to combined effect of autolytic and bacterial decomposition which is rapid in tropical climate. The following procedures should be adopted to keep the fish in good condition.
Figure 50. Modified Net with Measurement Detail
The moment the fish is harvested, they should be kept under shade and washed properly with clean water to remove the bacteria adhered to the surface of the body and the gills.
Gills and gut should be completely removed if there is no objection from consumers. Generally, colour of the gill is an indication of freshness.
Cleaned fish should be given a one minute dip in 0.2% sodium nitrate solution.
Cover the fish with layers of a mixture of ice and salt.
Cover with wet bags or clothes and transport it at once.
For safe delivery of live fry, fingerlings and brood fish to destinations, two systems are presently in use: the open system for short distance and the closed system for short and long distance transport.
This involves starving the fish prior to harvesting and keeping them in overcrowded condition for emptying their gut and to make them accustomed to the conditions of transport. Artificial feeding therefore should be stopped 1–2 days before harvesting. Although a number of containers and enclosures can be used for conditioning, the most common is the hapa made out of cotton or nylon mosquito netting material fixed in the pond or in a still water section of a stream or river, but always in shaded areas. After netting, the fry and fingerlings are transferred to the conditioning hapa (Fig. 51) and kept for about 6 h with continuous and vigorous splashing of water from all sides of the hapa. Conditioning time depends on the distance to be covered and the anticipated time of confinement during transport. During this period they pass their remaining excreta and the gut becomes almost empty. The optimum temperature for conditioning carps is around 26–29°C. In the case of brood fish the application of supplementary feed should be stopped 2 days before the proposed date for transportation. Handling during netting and transport should not be allowed. Conditioning of brood fish in hapas is not required. Risk of outbreak of diseases becomes high due to the stress created during transport and hence the use of antibiotics is recommended.
This is the traditional system of transport where fish seed materials are transported in open containers. These containers were earlier in the form of earthen hundies which have now been replaced by aluminium vessels of about 25–40 1 capacity (Fig. 52). Water is filled up to two-thirds of the total capacity of the vessel to transport about 1 000–5 000 early fry (12–15 mm) depending on the anticipated period of transport. Such vessels are normally carried manually or by train. When they are carried manually, a rhythmic jerky movement is created which keeps the water well aerated. Dead ones are periodically removed with the help of a piece of cloth and the water is changed partially but frequently during long distance transport. Earthen hundies help to keep the water cool, but due to high risk of breakage they are now going out of use. Bigger galvanised steel containers of about 50 to 200 1 capacity sometimes mounted on a thermal insulated base of wood or other materials are also in use for transport of fry and fingerlings for short distances. In the case of fingerlings or advanced fry transport, the mouth of the container is always kept covered with cotton or nylon mosquito netting material. The ever increasing demand for carp seed has created a great impact upon village level seed production activities in recent times. Farmers are now taking up induced breeding of carps and the seed are now being reared in their backyard or ponds. This method of open system of live seed transport for short distances is of significant relevance for localised marketing scattered throughout the region, in spite of its many limitations.
Figure 51. Conditioning Hapa
Figure 52. Aluminium Containers (Hundies) for Transporting Fish Seed
Plastic pools and canvas bags with varying degrees of capacity are also used for transport of fry/fingerlings and brood fish under open transport system. These are mounted over bicycle, motor van, tractor trailer, etc., and used for short distance transport.
Relatively bigger truck mounted open tanks are also in use with or without facilities for mechanical aeration and/or water circulation. Such tanks are used in organised fish seed marketing sector. Tanks vary in size but usually 3–4 tanks are accommodated on a truck. Fry, fingerlings and brood fish are usually transported up to distances covered within 3–4 hours with ease. Tanks are covered with wet cloth and some persons are employed for continuous but gentle splashing of water. Improvements have been made and now plastic cushioned lining is provided to the tank for avoiding physical injuries. Some sort of aeration or water circulation is provided by a pump during transportation. Such a system offers safe transport of live fish upto a distance of about 500 km with mortality as low as 5%.
For transporting live fish and fish seed over exceedingly long distances and from one country to another, closed system of transport is most suitable. In this system of transport live fish/seed materials are packed in closed containers with oxygen under pressure with airtight seals. Polythelene or vinyl chloride or other plastic bags of various capacities ranging from 15–35 1 are in use. These bags can be purchased ready made from the market or, if needed in larger quantity, can be made from cylindrical rolls. Widely used size is 47 cm × 46 cm which can be accommodated in 18 1 capacity biscuit tins after being filled with water up to one-third of its capacity. The water for such use should be clean and preferably from a tube well. Number of seed materials to be packed per bag vary according to their size and expected duration of transport (Table 40).
| Seed size (cm) | No. of seed (Range) | No. of seed (Average) |
|---|---|---|
| 1 | 1 000 – 10 000 | 5 500 |
| 2 | 500 – 5 000 | 2 200 |
| 3 | 200 – 1 000 | 600 |
| 4 | 200 – 500 | 330 |
| 5 | 75 – 300 | 225 |
| 6 | 50 – 200 | 80 |
| 7 | 25 – 100 | 70 |
| 8 | 25 – 50 | 40 |
After putting the required number of fish seed in the plastic bag containing water, oxygen is pumped into the water until it is saturated. The bag is then partially blown up with oxygen and tied with a leak proof knot.
These plastic bags are individually packed in cardboard, metal or wooden boxes to prevent any damage to the bags during transport. Biscuit or oil cannisters of 18 1 capacity are widely used for such purpose. It must always be kept in mind that the live fish packets should not be exposed to temperature over 30°C. Best results are obtained when it is kept between 20–28°C.
A simplified method suited to rural condition has been developed for fish seed transport in a closed system where instead of oxygen, a cycle pump is used to pump atmospheric air into the plastic bags containing fry in 6 1 of water. It has been observed that 500 mrigal fry (26–35 mm) can be safely kept alive for a period of 24 h with 1% mortality. At 300 fry/6 1 of water the fry survived for a period of 96 h without any mortality (Selvaraj, Mohanty and Ghosh, 1981).
Brood fish are also transported in some larger closed containers mounted on wheels and pulled by jeep or a tractor. The modified splashless live fish carrier (Mammen, 1962) is useful for transporting brood fish as well as fingerlings. This is a tanker having a capacity of 1 150 1 with lining of synthetic padding, autoclave type airtight lid and a built-in aeration system which works by the engine of the transporting vehicle using belt transmission. An oxygen cylinder is also kept on the carrier as a standby for emergency use.
A total weight of 250 kg of live fish can be transported in such a tank. About 90 000 carp fingerlings with fish to water ratio of 1 kg to 4.5 1 of water have been successfully transported to distant places.
A bio-gas-plant type of live fish carrier has also been designed by Patro (1968) which consists of an outer lower circular chamber of about 1.2 m diameter opening at the top to which is fitted the upper inverted one of slightly smaller dimension. The top of the inner chamber is closed and, provided with a valve and air vent. The outer lower chamber serves as a storage tank which is filled with water along with the fish to be transported while the inner chamber serves as an oxygen reservoir under pressure. It can transport 100 kg of fish at a time safely up to 5 h, thereafter refilling of oxygen becomes essential (Fig. 53).
Figure 53. Live Fish Carrier
Production of toxic gases such as ammonia and excess amount of carbon dioxide as metabolic waste products are the main causes of stress condition and mortality of fish in undrainable ponds. Drugs and chemicals are used to reduce the metabolic rate, thus cutting down the production rate of ammonia and carbon dioxide. Such situations reduce the stress effects. Under stress conditions fish become more prone to attack by pathogenic bacteria. Use of antibiotics and some other fish therapeutics help in reducing such risks. Some of the easily available fish anaesthetics such as Novocaine at the rate of 50 mg/ kg of fish, barbital sodium at the rate of 50 mg/kg of fish, tertiary amyl alcohol at the rate of 2 mg/4.5 1 can be used for anaesthetizing the fish to be transported. Ms 222 is also a common tranquilizer which can be used for anaesthetizing brood fish in a 1:10 000 to 1:30 000 solution for 15 to 20 minutes. Carbonic acid has been found to be useful in fish seed transport. A concentration of 500 ppm of carbonic acid in the transport medium itself was found to be optimum for rohu fry under oxygen packed transport (Mishra, Kumar and Mishra, 1983).
Important operational steps:
stop feeding 1–2 days prior to transport;
condition under shade up to 6 h before packing;
use tube well or chlorine free tap water or clear pond or river water;
select only healthy and vigorous fry/fingerlings;
plastic bags should be checked before and after oxygen packing to check any possible leak;
carriers of fish/seed containers should be covered to avoid strong sunlight;
when resting during the journey carriers should be parked under shade;
if atmospheric temperature is high, occasionally sprinkle cool water over the metalic containers to bring down the temperature;
before releasing, the bags or hundies should be floated in the water where the seed are to be released at least for 10–15 minutes to equalise the temperature;
slowly mix the pond water and gradually release the fish;
if anaesthetic is used, prior trials should be made as the doses vary with the water quality and the species of fish.
Most of the major cities and fish sale depots are far away from the rural fish production centres. In such situations marketing involves offering the products in proper form, time and place desired by the consumers. In fact, product marketing of any production system is the core activity upon which the future of the industry depends considerably. In case of fish production system, marketing assumes relatively greater importance because of the highly perishable nature of the product. In addition to fish, fish seed materials - spawn, fry and fingerlings - are also important products of pond fish culture, but these products are used by the industry itself.
There are areas that have a higher per caput production and also there is a regional variation in consumption pattern. Proper marketing strategy is needed to stabilize such imbalances in the larger interest of the producers and consumers. In some of the eastern states of India, especially in West Bengal and in countries like Bangladesh, freshwater carps are in maximum demand where 70–80% of the population are fish eaters. In some southern states, especially in Andhra Pradesh where freshwater aquaculture is emerging as an industry, the local preference for carp species is relatively less and hence the surplus is marketed to West Bengal. Calcutta markets in West Bengal receive about 30 000 t of fish per annum from other states of India. The existing price of freshwater carp in West Bengal is around US$ 3.0/kg compared to an average price level of US$ 1.5–2.0 in other states indicating the demand and supply gap.
The fish seed production/demand picture is just the reverse. West Bengal is a surplus state which produces maximum quantity of fish seed through controlled breeding and supplies to other states in India.
Marketing functions or services include many aspects such as collecting small quantities from many producers, grading, packing, transporting to distant city based wholesale markets, and distributing to retailers.
The term “ middlemen ” is often used to describe a wide variety cf collectors, agents and distributors serving as links between the producer and the consumer. Considerable portion of the fish is sold in fresh condition. In the absence of easy accessibility to the market, fish is sold to the middleman at the farm gate invariably at a much lower price than what it would have fetched in the retail market. Also, fish farmers who are generally poor, ignorant of market dealings, and financially indebted to money lenders are compelled to sell their produce to the middlemen in fulfillment of the conditions of loan taken for fish culture operation. Generally speaking, the fish traders and middlemen exploit the poor fish farmers.
Out of many market channels, the shortest and best possible channel in the interest of both producer and consumer is the direct one. But this channel is operative only during special occasions when the consumers need the fish in bulk for some social and festive celebration. There may be several functional links (about 4) between producers and consumers through each market channel and at every link they charge about 5–20% for their services. Usually the consumers pay about 70–80% more than the producer's price.
In addition to the seasonal variations in the market price, fish prices increase due to increased demand during the time of religious and social celebrations. The volume of fish sale is normally at its peak during March/April, mainly due to increased harvesting prior to pre-stocking pond preparation for the next crop. Price variations are also linked with the species and size of fish (Table 41). Prices are also related to state of freshness of the product. Fresh fish fetches a better price and are in greater demand than iced fish. The current market price of carp species in Orissa markets are given in Table 41 which gives more or less the general picture of prices in fish markets of Eastern India.
Until recently, the state fisheries institutions were the major channels for the collection/production and distribution of fish seed. Due to increased adoption of composite fish culture technique throughout India, severe shortages of fish seed supply have been felt, and to satisfy this growing demand the Government took immediate steps to increase the production of fish seed. Many state and private hatcheries were established during this period and extension services were put into action to promote induced breeding at farm level. As a result, many small and big seed producers emerged and consequently fish seed marketing became operational. Within a few years this trade has grown to a considerable size. There are two general patterns - the more or less organized one through fish seed syndicates and cooperatives and the other which is highly localised in operation. Collection of seed from scattered seed production centres and ensuring redistribution of the collection to fish farmers in remote villages is the responsibility of the organized sector, while a localised marketing system distributes fish seed to nearby villages through local agents. The price of fish seed varies according to size and species. Approximate cost of fish seed of carp species in Orissa State is presented in Table 42.
| Species | Retail market price (Approximate) (US $)* | |||
|---|---|---|---|---|
| Below 0.5 kg | 0.5 - 1.0 kg | 1.0 - 2.0 kg | Above 2.0 kg | |
| Catla | 1.5 | 1.9 | 2.2 | 2.5 |
| Rohu | 1.6 | 2.0 | 2.2 | 2.5 |
| Mrigal | 1.6 | 2.0 | 2.2 | 2.5 |
| Silver carp | 1.1 | 1.5 | 1.6 | 1.8 |
| Grass carp | 1.5 | 1.9 | 2.2 | 2.5 |
| Common carp | 1.3 | 1.6 | 1.7 | 1.9 |
* 1 US $ = 15.00 Indian Rupees
| Fish seed | Catla | Rohu | Mrigal carp | Silver carp | Grass carp | Common carp |
|---|---|---|---|---|---|---|
| Spawn** | 20.8 | 20.8 | 28.8 | NA | NA | 20.8 |
| Fry*** (25–30 mm) | 16.6 | 8.3–12.5 | 8.3–12.5 | 30.0–30.5 | 50.00 | 8.3–12.5 |
| Fingerlings*** (80–120 mm) | 60.0–70.0 | 40.0–42.0 | 40.0–42.0 | 55.0–65.0 | 80.0– 40.0- 85.0 | 40.0–42.0 42.0 |
* 1US $ = 15.0 Indian Rupees;
** Price/100 000;
*** Price/1 000; NA = Information not available.
