Construction of Ornamental Fish Farm in Galagedara Area

By

M. D. N. Perera (AG/07/265)

A mini project report submitted in partial fulfillment of the requirement for the

Inland and Marine Fish Management subject (AS-4104)

2012

Majoring module: Animal Science and Technology

Department of Animal Science

Faculty of Agriculture

University of Peradeniya

Peradeniya

Sri Lanka

Approved by

…………….………………………………

Prof. Udeni Edirisinghe

Lecturer

Department of Animal Science

Faculty of Agriculture

University of Peradeniya

Peradeniya

Date…………………..

Abstract

Ornamental fish rearing is a world wide hobby and exports of aquarium fish by Sri Lanka

have been increasing substantially over the past ten years. Sri Lanka exports fresh water fish,

brackish water fish and marine water fish. But it is less than one present of the global market

value. Over 75% of income comes from wild catch marine and brackish water fish species.

Western countries have been putting restrictions on the importation of fish caught from the

ocean. This has led the Sri Lankan government to promote freshwater ornamental fish production

in the country.

Ornamental fish culture is widely spread in Sri Lanka but the breeders and exporters are

mainly limited to the Colombo area due to easy to transport for exports. But this are land are

limited and production cost is high. Central province has favorable climate for fresh water

ornamental fish species. Also land, labor and water is available in central province and these

recourses can use for improve the production of ornamental fish industry.

The main purpose of this project is start the start the ornamental fish farm in Galagedara

area and give knowledge to peoples to start their own fish farm. This sector assumes special

significance due to its huge potential in providing employment to the people hailing especially

from rural sector and as a foreign exchange earner. The low production cost and higher returns

with in a very short time, growing demand for fishes both from domestic and international

market are the major attractions of this.

Content

1. Introduction 2

2. Selected Area 3

3. Suitable fish species 3

I. Platy fish 4

II. Molly fish 4

III. Swordtail fish 5

4. Fish breeding 6

5. Breeding Tanks 7

6. Activities in breeding 8

I. Size and number of tank 8

II. Spawning and breeding 8

III. Hatching 8

IV. Fry raising 8

V. Fingerlings raising 9

VI. Stocking 9

VII. Size and number of tank 9

7. Feeding fry 10

8. Feed formulation 11

9. Mud ponds 12

10. Fish diseases 15

I. Non infection disease 15

II. Infection diseases 16

a) Bacterial diseases 16

b) Fungal diseases 17

c) Viral diseases 18

d) Ecto parasites 19

e) Endo parasites 19

Introduction

Ornamental fish keeping is a very popular over the world over a thousand years ago. Only a few

hundred of the 4000–5000 fish species currently being kept as pet fish worldwide are very

popular and commonly kept by a large number of fish hobbyists.

The ornamental fish industry in Sri Lanka has a long history. In the early 1930’s several small

scale importers, breeders and hobbyists in Sri Lanka. The ornamental fish industry was

commercialized by a few entrepreneurs about 50 years ago and has now developed in to export

market. Sri Lanka exports locally wild caught marine fish, brackish water fish, freshwater

species and captive breed fresh water species.

Exports of aquarium fish by Sri Lanka have been increasing substantially over the past ten years.

The value of ornamental fish exports increased from LKR 30 million in 1981 to LKR 370

million by 1997. This growth has been mainly because existing importing markets have

expanded and Sri Lankan exporters have acquired access to new markets. Around 75 per cent of

ornamental fish exported from Sri Lanka are marine varieties. In recent years, however, Western

countries have been putting restrictions on the importation of fish caught from the ocean Wild

catch marine ornamental fish species cause to ecosystem imbalance and increase breeding of

ornamental fish species is suitable method of increase the growth of ornamental fish industry.

This has led the Sri Lankan government to promote freshwater ornamental fish production in the

country. Central province, especially Kandy and Matale districts are endowed with favorable

climatic conditions that make it suitable for rearing and breeding freshwater fish.

For building proper transport system and marketing Chanel help to involvement of rural people

to ornamental fish industry. In Kandy district have available resource like lands, water

availability, family labor and suitable climatic condition more favorable in successful production

of many species of fresh ornamental fishes and plants.

Selected area

Galagedara area was selected to establish an ornamental fish farm. Galagedara is a major town

in Kandy district, central province. It is connected to Sri Lankan transport network by Kandy-

Kurunegala road. Galagedara is away from 27 Km to Kandy and 32Km to kurunagala.

Glagedara is located in the centre of the island and in a high elevation, it has a relatively wetter

and cooler temperatures than that of the tropical climate of the rest of the country. The area has

its dry season from December through to April. From May through to July and December to

January the region experiences its monsoon season, during this time the weather is rough and

unstable. From March through the middle of May is the intermonsonsoonal period, during this

time there is light rain and strong humidity. The humidity is generally between 70% to 79%.

This area has suitable land for start ornamental fish farm and water is available. This area

suitable for platy, molly and sword tail like fish sepsis. These fish species can grow in this area

without any problems. Also Rambodagalla fish breeding center is near to this area and it is an

advantage to start ornamental fish farm.

Suitable fish species

This area has cooler temperature and high relative humidity compare to other areas of Sri

Lanka. Select suitable fish sepsis is advantages situation to get high income during fish farming.

Viviparous fish species can breed easily compare to oviparous fish species and can breed without

having any advanced knowledge. Suitable fish species for Galagedara area are

Platy fish species

Molly fish species

Sword tail fish species

Platy fish

Platy is a common name for two related species of freshwater fish in the genus Xiphophorus.

Both species are livebearers, similar to other fish of the family Poeciliidae, such as the guppy and

molly. Platies are native to the east coast of Central America and southern Mexico.

Platy's prefer water temperature at 24.4-26.1 ºC. Platy's are very hardy, and can adapt to many

types of water. PH can rage from acidic (6.5) to basic (8.2). Platy's have even been reported to

live in brackish water (lightly salted water) and experience no negative effects of it.

Females will be longer, and also have wider stomachs than males. Female Platy's will have three

almost identical fins, two a little further up the belly (closer to the front) than the rear, and with a

male, the two frontal fins will be the same, but the aft fin will be much smaller, and pointed.

Diets are flake, frozen, freeze dried, and live food is all accepted by the Platy, and all should be

fed to them on a rotating basis. Although flake can be their staple diet, it will keep them more

healthy to feed varying food, and help them show better colors. Fry will also be consumed by the

adult fish.

Plate1. Platy fish

Molly fish

The molly, Poecilia latipinna, is a species of fish, of the genus Poecilia. The body of the molly is

essentially oblong. The head is small and dorsally flattened, with a small, upturned mouth. The

caudal peduncle is broad and the caudal fin is large, rounded, and sometimes tipped with black.

The pelvic fins originate at a point anterior to the dorsal fin. In mature males, the dorsal fin is

greatly enlarged and colourful and the caudal fin is similarly colourful.

The body is generally light grey, although breeding males may be greenish-blue. Several rows of

spots occur along the sides, back, and dorsal fin. Often, these spots blend together, forming

stripes. Aquarists have developed many colour variations in this species with melanistic,

leucistic, albino, and speckled forms known.

The natural lifespan of mollies is short, particularly in the case of the males, which may live less

than a year after achieving sexual maturity At one year of age, males typically range in size from

0.5-3 inch, while mature females are likely to be 0.5 - 2.5 inch. The size of adult males is directly

correlated with population density. The greater the population, the smaller the average size of

males. The maximum recorded size for this species is 150 mm.

Mollies produce broods of 10-140 live young, depending upon maturity and size, and females

may store sperm long after the demise of their relatively short-lived mates. There is no parental

care exhibited by this species. A ratio of three females to one male is preferred, as with all live

bearers, because the females are harassed by males to the point of exhaustion, and having more

females gives the others a rest.

Plate2. Molly fish

Swordtail Fish

The name swordtail is derived from the body of the male swordtail. The bottom ray of his caudal

fin is extended and points out from the body like a sword. Red, black, green, albino and even

neon coloured swordtails present. Mature male swordtails are easily identified by the long

sword-like extension to their tail. The females also have a dark spot near the anus called the

gravid spot. Swordtails can tolerate a moderately wide range of water quality conditions,

particularly dissolved oxygen (>2.0ppm) and temperature (10-30°C). They can grow 6.8-7.8 pH

range.

The Swordtail fish is a livebearer and female Swordtail will give birth to fry instead of

depositing eggs. The male Swordtail fertilizes the eggs inside the female and the eggs develop

into fry inside her belly. It is easy to get Swordtails into spawning condition. It is even possible

for a female Swordtail reproduce in an aquarium without any male Swordtail present, since she

can store enough sperm to fertilize six batches inside her body. Swordtails are prolific breeders

and can produce up to 250 fry per brood. Swordtails can grow up to 13cm and reach maturity at

25-30mm at 10-12 weeks. Swordtails are an omnivore that will eat commercially prepared flaked

foods and algae as well as freeze dried bloodworms and brine shrimp.

Plate3. Swordtail fish

Fish Breeding

Breeding is a complicated process which should be performed very carefully. It also

requires some knowledge of biology and especially the basics of genetics. The objective of

breeding to evolve such breeds in such a way that the desirable characters are kept expressed or

retained and the undesirable characters are kept unexpressed or removed.

The most common types of breeding are inbreeding, out breeding and grading up.

Inbreeding is breeding of related animals and out breeding is breeding of unrelated animals.

Under inbreeding one can have close breeding and line breeding. Close inbreeding between

father and daughter and mother and son and own brother and sister should be avoided by all

means. Under out breeding one can have out crossing (crossing of unrelated individuals of the

same breed) and cross breeding (breeding of unrelated animals of different breeds). In grading up

the local none descript breeds are upgraded by successive breeding with selected pure breeds.

Select the breeding stock according to the principle of selection. Only the good ones are

selected for breeding. Fishes that are true to the desired characteristics, fast growing, active,

agile, good feeders, good size and shape are selected for breeding. Defect or diseases fish should

not be selected for breeding purposes.

Breeding record should be maintained. The breeding record should contain the

identification mark or number of the males and females, date of breeding and spawning,

hatching, approximate number of hatchlings, fry and fingerlings, etc. The breeder should note

any other relevant detail related to breeding. These are some of the basic principles and practices

one should follow in breeding and multiplying any type of animal for economic advantage.

Rearing good brood stock is main point in ornamental fish industry. Because brood

stocks are not suitable to production it affect to production of fry. When buying brood stocks

should check for disease, heredity, growth rate and buy active fish. Do not use mature fish.

Breeding Tanks

For fish breeds can use different type of tanks. Normally fish breeders use cement tank

and aquarium glass tanks. It depends on resource availability and type of fish species. For

medium and large scale farmers cement tanks more profitable than glass aquarium tanks.

Cement tanks build using concrete and make group of tanks more profitable. Normal size

of fish breeding tank is three meter to three meters and high is 45- 60 cm. the size of tank

different from fish species and place where tank constriction. Before fish introduce to new tank it

should fill with organic manure and stay about to one week to remove toxic materials. When

using a fish tank one cycle to another cycle it should be dry at least one day for remove pathogen

prevent the spread of disease. If tank has disease animals tank should using antiinfection agent.

When store fish into the tank mainly consider fish density. Because fish require suitable space to

growth their optimum size.

Activities in breeding

There are a number of activities performed in a sequential order to raise the fry’s or

fingerlings. Several tanks are required for carrying out a number of activities such as stocking the

male and female breeders, spawning and breeding, hatching, fry raising, raising of fingerlings

and rearing up to maturity.

Stocking

Stocking means to stock the selected mature males and females of ornamental fishes. The

tanks used for this purpose are called stocking tanks. The stock also is called the breeder stock.

The male and female breeder stocks of the same breed and different breeds are kept in separate

tanks. The number of tanks required for stocking depends on the number and size of fishes of the

same breed or different breeds.

Spawning and breeding

Spawning means release of eggs by the female single or in a group. In the group they

look like an egg-mass of jelly like substance. This egg-mass remain floating while being attached

to some kind of fibrous material or plant parts. The single eggs either float around or sink deep to

the bottom of the aquarium tank. Breeding usually means mating also. But in the case of fishes

the fertilization of the eggs takes place outside after the spawning is completed. At the time of

spawning the male fishes release the milt (sperm excretions) on to the eggs and instantaneously

the eggs get fertilized. In the case of fish breeding the term breeding signifies all these processes.

Hatching

Hatching is a biological process by which the developing embryo in the egg comes out in

the form of young fish called fry. Hatching can be done in the breeding tank or in another tank

called hatching tank depending on the convenience of the breeder.

Fry raising

The fishlings up to 15 days old are called fry. Ornamental fish sellers and growers buy or

sell fishlings at fry stage. The fry rearing stage last for about 15 days. For the first few days the

fishlings may not need any nutrition from outside since they have part of the yolk, from the egg

from which each one came out, is attached to their body. This yolk reserve is slowly absorbed

into the body providing the necessary nutrition. After two days they begin to eat very small

particles of feed. One of the best forms of feed is to powder the yolk of the boiled egg and tie it

in a fine cloth tight and kept under pressure with the help of a clip fixed on the small bundle and

hanging it in the tank water conveniently for the fry to pick at the particles of the yolk oozing out

of the bundle under clip pressure. The most important thing to be remembered in fry rising is to

avoid overcrowding of fry in the fry raising tank.

Fingerlings raising

Fishlings between 15 to 90 days old are called fingerlings. Among them those that

between 15 to 60 days may be considered to be in primary fingerling stage and those 60 to 90

days to be fingerlings in secondary stage. Depending on the convenience one can have further

categories of fingerlings such as one month old, two month old and three month old, etc.

Size and number of tank

The size of the tank may be 45-90 cm long, 25-45 cm width and 25-45 cm height.

Usually the width and height is maintained equal. Separate tanks are required for keeping the

males and females. At the time of breeding one female and two males are placed together in one

tank. After spawning and fertilization the males and the females are returned to their respective

tanks. The number of fishes placed in a tank depends on the size or the length of the fish.

Generally one centimeter long (excluding the tail) fish require 75 sq cm tank areas.

Therefore, in a tank of 60x30 size we can keep 24 fishes (60x30/75 = 24) of one centimeter long

or 4-5 fishes of five cm long (60x30/75x5 =4.8) or 2-3 fishes (60x30/75x10=2.4) of 10 cm long.

Accordingly one has to estimate the number and size of the tanks he needs for breeding. Few

stand-by tanks are also needed to cope up with any unforeseen demands during the breeding

period.

It is advisable that the breeder stocks are kept in bigger tanks of at least 90x45x45 cm in

size. Therefore, depending on the number of breeder stock and their size the breeder can estimate

the number and size of the tanks required. Similarly the number and size of the tanks required for

other breeding related activities can be estimated. Accordingly all the required number of tanks

can be constructed and established.

Feeding Fry

Newly hatched fry are very small and they can’t eat large feed particles. Also those feeds

pollute the water, change the water quality and it affect to disease spared quickly. Live food

almost always give the best results because growth rate in fish is noticed to be at least three times

faster when they eat live food. Fry need small quantity of feed for several times per day. Because

their growth rate is high in young period.

Infusorians

Infusorians is a suitable food for very small fish fry. (Guppy, fighter fish) Infusorians are

minuscule single cell organisms that live in water. To cultivate Infusorians need tap water, some

bruised vegetables and a few clean containers. Fill the jars with the water and add some bruised

vegetables to each jar. Bruised lettuce leaves or banana skins are suitable for this. Place jars in

warm place and after 3-4 days infusorians is grow in water.

Brine shrimps (Artemia salina)

Brine shrimps live in saline water and post larva of brine shrimp is good sours of feed for

small fry. Most fish fry is large enough to eat brine shrimp as their first food. In commercial

level people use brine shrimp for larval feed.

Artemia eggs in store in bottles before feed it should hatch. For this need 28-30 ppt saline

water and should aerate the water. Ph should 8-9 and temperature 25-30 ºc. Brine shrimp eggs

will typically hatch after 48 hours or even earlier. They sensitive to light and placing light source

they come to that place and after catching can feed to fish fry.

Paramecium

Paramecium is a complex, single-celled protozoan that is a great supplementary food for

your fry. This feed is very easy and cheap to prepare. To prepare a culture need clean water and

cabbage leaves. After adding cabbage to water it should place in light place. Paramecium

normally grow in 7-14 days and it can use for small fry.

Microworms

Microworms are small nematode worms that grow to be around 0.5-1.5 mm in length.

They are a great food source for fish fry, especially fry that are too big for infusoria and too

small for brine shrimp. To culture microworms need bread, soy flour, hot water and culture

media. Using bred make a pulp and incorporate microworm culture and they grow after 3 days.

When feed to fry should not include bred, because it may spoil the water. For this can use filter

paper to separate microworm from culture.

Egg yolk

Egg yolk prepared at home can also be used to feed fry. Egg white content high amount

of protein and yolk contain high amount of protein. For produce larval feed using eggs, egg

content should add to the 60 ºC hot water and beet hardly. These mixtures can store in

refrigerator and can feed to fish larva.

Feed formulation

Like any other organism fish also requires various nutrients for repair and maintenance of

the body and for the growth and development Proteins, lipids and carbohydrates are the nutrients

that furnish the required energy for maintenance, activity, molting, growth and reproduction. The

non-energy nutrients are the vitamins and minerals which have diverse physiological and

biochemical functions and are extremely important in deciding the efficiency of a diet.

Essentially, an ideal feed should have adequate levels of bio-available energy, a blend of

essential amino acids and fatty acids and adequate levels of vitamins and minerals. Besides, all

these nutrients must be found in balanced proportion in the diets offered to the cultured fish for

its effective utilization.

In feed formulation, ingredients are chosen on the basis of chemical composition,

nutritional values availability and cost. To satisfy nutrient requirements of various species and of

varying age group of fishes, various combinations of raw materials are prepared. Feedstuffs are

classified into two major groups in fish culture and those are energy feedstuffs and protein

feedstuffs. Energy feedstuffs contain less than 20 %crude protein and examples are rice bran,

wheat flour, and maize like plant origins. Protein supplement feedstuffs contain more than 20%

crude proteins and most are animal origins. Examples are fish meal, blood meal, bone meal,

chicken offal, etc.

Commonly available ingredients are: legumes, seeds, groundnut oil cake, mustard oil

cake, coconut flour, rice polish, broken rice, cattle blood, bone meal, poultry by-products, trash

fish, fish silage, fish meal, milk byproducts etc. Fish required crude protein content more than

40% and need essential amino acids and vitamins. Most feedstuffs contain antinutrient factors

and its harmful to fish and these antinutrient factors should destroy using suitable methods.

Tripsin inhibitor in row soybean can destroy using heating.

For produce formulated feed feedstuffs should break to small particles and make powder.

It should sieved and each ingredients mix thoroughly using sewing. When mixing small quantity

and large quantity separate and mix more beneficial. In mechanical mixing special time

combination need to mix thoroughly. Mixing is important due to make homogenous feeds.

Wheat flour use as mixture and should make a pulp using hot water. Yeast adds to make pores

inside feeds. Then using string hoppers and steam feed ingredient in one hour increase the

gelatinization in feeds. Then feed should dry to reduce moisture content and should reduce up to

12%.

Mud ponds

In ornamental fish industry mud ponds use to rear and grow fry to marketable stages. Fish

grow according to space availability and they grow fast in mud ponds compare to cement ponds

and aquarium tanks. The main point in the construction of a fish pond is to make sure that it

remains intact for a long period of time so that it becomes a permanent asset that will give

regular income to the owner of the pond.

The construction of fish pond involves the knowledge of variety of things like the type of

soil, the angle of retention of a particular type of soil, soil management for construction, the

interaction relationship between water and soil, the behavior of soils under the permanently wet

and submerged conditions etc. Fish rearing involves supervision and regulation of reproduction,

feeding, disease control, control of the size of the fish and the stocking and maintenance of the

ponds. This means full control of the fish rearing situation in the constructed pond so that always

an optimum range of environmental condition is made available to an optimum number of fish

per unit area of the pond.

The construction of the pond should be such that there should be least amount of seepage

or leakage loss of water, safe from siltation, side collapse and filling of the pond, safe from other

predatory terrestrial and aquatic animals, tree from the possibility of flooding or overflowing of

water or drying or serious reduction of water. The pond also to be constructed in such a way that

feeding and caring of the fish, disease control and supervision, control of inlet and outlet of water

from the pond and finally the netting and harvesting of fish becomes easy.

Key points in Pond Construction

Certain points should be kept in mind while constructing the fish ponds. These factors

depend on the type of fish farming and scale of fish farming.

The size

There should be proper size and shape for ponds used for various poses like breeding,

spawning, hatching, nursery, rearing and stocking. Under such conditions size of pond at least a

pond size of 70 ft long, 35 ft width and 4-5 ft water depth. The ratio between the length and

width of the pond should be maintained between 2:1 to 4:1 (the width should be less than half the

length). This is to provide the fish long stretches of swimming and feeding space and also for

easy netting.

The sides

The sides of the pond should be made really firm and non collapsible. This is done by

various ways like giving proper slope, compacting the soil, building or lining the sides with

bricks or stones or concreting etc. A collapsed pond is like a broken vessel which cannot hold

water in it.

Water retention

The pond should retain sufficient water throughout the rearing season. This can be made

by compacting the soil, paddling the soil, adding more clay and other binding material to soil at

the bottom and at the sides of the pond.

Drainage

There should be proper drainage facility. We should fix a proper outlet from the pond

through which we should be able to drain the pond fully or partially at any time without allowing

the fish to come out.

Inlet

The inlet brings in water into the pond. This should be constructed in such a way that silt,

leaves or other plant parts should not come into the pond. The inlet should also control the

quantity of water coming into the pond whether during flood, rain or dry season. In short, inlet

controls the quality and quantity of water coming into the pond.

Outlet

The outlet could be same as drainage or separate. In a running water pond a separate and

permanent outlet is fixed besides a drain. The outlet is fixed in such a way that the fishes from

the pond should not escape. The water level in the pond is maintained and the quantity of water

flow can be controlled.

Bunds

Proper bunds of about 2-2.5 ft. height and of convenient width is needed all around each

pond. These bunds serve not only as boundaries but also as passages to move around and

between ponds. The dimensions of the bunds such as length, width at the bottom and top, the

height and thickness of the bunds should be even and uniform through out the bunds. Similarly

the compactness of the bunds also should be uniform.

Fish diseases

One of the most limiting things in ornamental fish farming is fish diseases. Fish disease

identification in early stage is important to control speeding of diseases. Breeding stock should in

a good healthy for produce proper offspring’s. Proper checking of fish is best method to identify

disease in early stage.

Fish diseases are categories to two types.

1. Infectious disease

2. Non infection disease

Non infection disease

Non infection diseases are not transmit vertically or horizontally. These are the main

reasons for non infection diseases.

I. Heredity

Heredity happens due to mutation of genes. Some heredity factors are important to produce new

verities. If offspring have deformation parents should be removed.

II. Nutrients

Ornamental fish require high amount of nutrients for their growth. Carnivores fish need 40%

crude protein and omnivores need 30% crude proteins. Some essential amino acids and limiting

amino acids should give externally using feeds. If animal haven’t proper nutrient condition that

promote stress and that help to spread diseases.

III. Injuries

Injuries happen due to the handling of fish and mechanical damage. When fish handling should

use proper equipments avoid sharp edges in tanks.

IV. Physico chemical characters

Physical and chemical character of water is important to prevent diseases. If physio chemical

characters not suitable, fish spend energy for unfavorable condition and it is stress to the animal.

Optimum condition for fish

PH - 6.5-8.5

Temperature- up to 30 ºc

Alkalinity – 100

Hardness – 25

Turbidity – 25-30cm

Dissolve oxygen- above 30mg/L

V. Toxins

Due to human activities different chemicals introduce to water. Some of these chemicals are

harmful to fish. Also phytotoxins is toxin produce by the plankton. Highly nutrient water toxins

are growing well and during decomposition reduce the biological oxygen demand in the water.

Infection diseases

Infection diseases are transmitting vertically and horizontally. Fishes are infected by many

disease causing organisms such as virus, bacteria, fungi, protozoa, nematodes, and internal

parasites like tape worms, crustaceans etc.

Bacterial diseases

There are a number of bacterial diseases occurring among the cultivated fish. The common

diseases are described here.

1. Tail and fin rot

This disease is characterized by the white margins on the fins and putrefaction of the fins

and tails. As curative measure feed the fishes with a feed mixed with either the antibiotic

terramycin or sulphadiazine at the rate of 100 mg per kg of feed. The fishes are also given

common salt bath or formalin bath in 3% salt solution. Dipping in a solution of 250 ppm

potassium permanganate for, two minutes is also found to be effective.

2. Eye disease

The eyes look reddish the lens become cloudy affecting the movement and feeding.

Eventually the fish become weak and die resulting in poor production.The treatment for this

disease is the same as those pre-scribed for the previous bacterial disease namely the salt water

bath, antibiotics and dip in a solution of potassium permanganate.

3. Dropsy disease

Dropsy disease is characterized by the accumulation of water in the body cavity or scale

pockets. It is mainly because of the dysfunction of the kidney. Excessive accumulation of the

organic matter is considered to be one of the factors causing the occurrence of this disease. It is

caused by the bacteria called Aeromonas species. The treatments are the same as those

prescribed for the above bacterial diseases. General sanitation and removal of excessively

accumulated organic matter are additional help in controlling this disease.

4. Ulcers

Ulcers are formed on the body of the fishes. These ulcers vary in sizes from pimple like

structures. to very conspicuous sores. Besides contamination from other affected fishes excessive

accumulation of putrefied organic matter at the bottom of the ponds and canals is a favorable

Condition for the incidence of this disease.

5. Columnaris disease or reddish blotches

Columnaris disease is characterized by the reddish bruises, oozing of blood and formation

of clots at the posterior part of the fish. Besides excessive accumulation of the decomposed

organic matter higher stocking density is also a reason for the incidence of this disease. The

treatments are same as those prescribed for the other bacterial diseases besides the general

sanitation and prevention of excessive accumulation of the organic matter.

Fungal diseases

These diseases are caused by various organisms belonging to fungi family. There are many

fungal diseases affecting the fishes in the commercial culture.

Saprolegniasis

This is also known as "water mold disease" or "aquatic fungus disease". This is caused by a

group of fungi belonging to Saprolegnia mold. The hyphae of the mold grow extensively giving

the appearance of cotton like growth on the outer tissue of the body of the fish and can be clearly

seen. Several species of this fungus are known to cause the disease showing the main symptom

of cotton like structures.

A bath of 5% solution of common salt is found to be eftectivein controlling this disease. By

treating the pond with Malachite green at the rate of 0.1 gm per litre of water is another method

of controlling the disease. A bath of 0.5 gm of copper sulphate per litre of water or one gm of

potassium permaganate per litre of water is another alternative to the bath at common salt.

Branchiomyces

Branchiomyces is also called gill rot from the symptom seen in the fishes. Almost all the

species are affected by this disease. The blood vessels are blocked due to the disease, leading to

the death of the fishes. Addition of lime at the rate of 150 kg per ha and bath to the infected

fishes in 3-5 % solution of sodium chloride for 3-4 minutes are also found to be effective in

controlling this disease.

Viral diseases

Virus is considered to be the lowest form of life and the link between the living and non-

living. Prevent spread of viral disease limit the transport of water, plants, fish and planktons.

These are vector for viral diseases. Vaccination is done for prevent viral diseases. Common viral

disease describe here.

Pox disease of carps

Spring viremia of carp (SVC)

Swim bladder inflammation (SBI)

Viral renal disease of eels

Channel catfish viral disease

Lymphocystis disease

Ecto parasites

Argulosis

Argulus sp is a crustacean organism affecting the most fish species. The organism attaches

itself to the body of the fish causing irritation and as a result we can notice rubbing behaviour of

the fish, trying to get rid of the irritating organism. Continued infection leads to emaciation and

pigmentation on the body surface. Excessive deposition of decayed organic matter at the bottom

of the pond is an additional cause for the infestation of the disease.

Hence prevention of deposition of decayed organic matter is a prerequisite to control the disease.

Pond treatment with gamrnaxine at the rate of 0.2 mg/litre of water or bath in 3% salt solution of

infected fishes for 3-5 minutes are the measures that can control this disease.

Learnia

Learnia attached to gills and it cause to anemic condition of fish.

Endo parasites

Nematode diseases

Nematodes are microscopic type of worms that are found in the soil, plants and animals.

Some nematodes live on fishes as parasites. Nematodes which parasitises on fish are divided into

two: those which use fish as the final host and those which use fish as the intermediate host.

Majority of the first ones resides in the alimentary canal while some in the gills, eye sockets,

body cavity, muscles etc. So far the problems due to infestation of nematodes have not come up

to any significant level. For prevent nematodes give wormicide mix with feed and feed to fish.

REFERENCES

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