III. WHAT WORDSCAN BE USED TO DESCRIBE THE PIKE AND

Text 5.

Reproduction and Life-Cycle of the Perch.

VOCABULARY:

Breeding habits.

The egg-laying, or spawning, takes place in spring when the weather is warm (end of April and early May). The Perch gather in great shoals in shallow quiet backwaters overgrown with weeds where the water is sufficiently warm.

The eggs laid by the female remain glued together in long strings which hang on the weeds. The males excrete jellied fluid containing sperms.

Once realized into the water, the sperms swim actively towards the eggs; the different cells fuse and fertilization takes place. The nuclei and protoplasm of the sperms and ova unite. Two cells merge into one giving rise to- a new living organism.

Development.

The fertilized egg of the Perch divides into two ceils. The cells redivide - so that four are formed. This process continues until a multicelled embryo is formed.

The embryo develops tissues and organs. In about 5 or 6 days it becomes a small (0,5 cm. long) larval fish, with a yolk sac on its belly - the remainder of the food reserved in the egg for its development. When the supply runs out, the larva feed on microscopically-small weeds, infusorians and tiny crustaceans (Daphnia and Cyclops), and grows into a young fish which is very much like the adult Perch.

Shallow backwaters are most suitable for spawning: the temperature of the water is higher; there are plenty of weeds on which the egg-strings hang; the plants provide a rich supply of oxygen. As a rule, there is no shortage of tiny living organisms for food for larval fish and small fry.

And yet these relatively favourable conditions hold hazards for the development of the young. Some of the eggs may be left underfertilized; many of the eggs are devoured by other animals. Finally, there is always the possibility that the water level will fall due to hot weather, or oxygen supply will prove insufficient.

The only way to escape extinction is the laying of tremendous number of eggs. One ovary which weighs about 200 gr., normally contains between 200,000 and 300,000 eggs. The number of sperms discharged by the male Perch is much greater.

On the other hand, some fishes lay very few eggs, for instance, the Stickleback (only 60 or 70). But these eggs are deposited in nests composed of grass or weeds and are protected by the male.

The behavior of the Perch at spawning time is very complex and may lead to the conclusion that it is even conscious. In fact, it is promoted by a chain of hereditary unconditional reflexes. Everything is performed instinctively.

spawning - нерест shoal - косяк backwaters - заводь fertilization -запліднення nucleus - ядро ovum (pi. ova)-яйце larval - личиночний

yolk sac - жовчний мішок

crustacean - ракоподібний

small fry - мальки, молодь

ovary - яєчник

stickleback - колюшка

unconditional reflex - безумовний рефлекс

I ANSWER THE QUESTIONS: .

1. What is understood by fertilization? Describe the process using the Perch as an
example.

2. What changes does a fertilized ovum undergo in its development⁰

.3. What conditions are essential for the development of the ova and the young fish? 4. Why does the Perch lay so many eggs?

II. GIVE THE EHGLISH EQUIVALENTS TO THE FOLLOWING:

самка, самець, виділяти рідину, зливатися, запліднення, клітина, зародок бути придатним для нересту, запас кисню, вимирання.

Ш. COMPLETE THE SENTENCES:

1. The fish gather in great....

2. The female lays ....

3- The males excrete ....

4. Fertilization takes place like this ....

IV. FILL IN THE GAPS WITH THE WORLDS GIVEN BELOW:

1. The process of dividing the ceils continues until... is formed.

2. It develops ... and ... .

3. ... feeds on the remainders of the food in the egg for its development

4. Shallow backwaters are most suitable for....

5. The only way to escape ... is the laying of tremendous number of sees.

fish.

organs, extinction, a multicelled embryo, organs, tissues, soaring, a larval

V PUT THE SENTENCES INTO UKRAINIAN WITHOUT DICTIONARY AND USE THEM TO RETELL THE TEXT:

1. The egg-laying or spawning takes place in spring.

2. The Perch gather in great shoals in quiet backwaters.
3.The fertilized egg of the Perch divides into two cells.

4. This process continues until a multicelled embryo is formed. 5 The embryo develops tissues and organs.

6. In 5-6 days ii becomes a small larval fish and then grows into a young fish.

7. Shallow backwaters are most suitable for spawning.

Text 6.

The Pike and the Sazan.

Scientists have described up to 20,000 different species of fish which are living today. Many have been found fossilized - they have lived on our planet but have become extinct.

Some fish inhabit fresh-water rivers and lakes; others prefer the salt water of the seas and oceans. There are fish which keep close to the bottom; others swim nearer the surface. Some are vegetarians adding to their diet slow-moving animals; others catch swiftly swimming prey.

Their different ways of living influence their anatomy. You will notice these differences if you study the general characteristics of a few different species.

The Pike is long and slender and has a big head narrowed at the tip. The Sazan is broad and thick with a small head.

The Pike has an enormous mouth equipped with rows of formidable-locking teeth curved backwards. Because of their teeth, pikes should be handled very cautiously even when caught on a fishing line. The Sazan, on the other hand, has a small mouth and teeth.

Why is the difference so great? After all. both varieties live in the same rivers.

The explanation is to be found in their diets. The Pike and Sazan eat different methods of obtaining it.

The Pike is carnivorous. It eats fish. You can see it sometimes, motionless among the weeds. As soon as fish along, the Pike darts forwards like an arrow, its mouth wide. Pikes have been known to attack ducklings, water rats and other animals. The powerful tail near the soft dorsal fin and the anal fin are attached, as well as the long slender body, help the Pike to swim swiftly in pursuit of its prey. The sharp teeth curved backwards hold the victim so that even the slime covering its body does not help.

The Pike's colour pattern facilitates the pursuit of its greedy and destructive habits, it can easy conceal itself. It is mottled green, with dark bands and difficult to distinguish from the weeds among which it hides when waiting for its prey.

The Sazan has different habits. It does not hunt other fish but feeds on a mixed diet of insect larvae, mollusks, worms and even vegetable matter.

The Sazan locates its food in the river mud and silt by means of two sensitive feelers on its upper lip. The mouth is small and there are no teeth. There are no need of them. Down in its pharynx are several blunt teeth used to crush the shells of mollusks and grind vegetation.

The shape of the Sazan's body is also different from that of the agile Pike. It is taller and thicker and the tail is rather weak.

The peculiarities in anatomy and habits are due to the fact that their ancestors did not live in identical environments. They ate different food and developed their own methods of obtaining it.

VOCABULARY:

curved backwards - загнуті назад

mottled green - в зелених л'ятнах

larvae - лІчинки

feeler - щупальце

pharynx - глотка

shell - мушля, черепашка

ancestor - пращур

pike - щука

fossilize - закам'яніти,

vegetarian - вегетаріанець

prey - здобича

formidable - Грозний

carnivorous - хижий

in pursuit of- в погоні за

I. ANSWER THEQUESTIONS:

1. What structural peculiarities indicate that the Pike is a greedy and voracious
hunter?

2. How is the Sazan distinguished from the Pike?

3. Why are they different?

II- TRUEOR FALSE STATEMENTS:

1. Nowadays the researches still find many species offish fossilized.

2. Fish can live in the different environments, keep the various diets, but all these
factors do not affect their anatomy at all.

3. The Pike and the Sazan belong to the similar species offish.

4. These fish prefer feeding on the same food to using different methods of
obtaining it.

5. The Pike is a carnivorous fish being able to attack even small birds and animals
living in water.

6. The Sazan prefers feed ins; on insect larvae, mollusks. worm to hunting other
fish.

III. WHAT WORDSCAN BE USED TO DESCRIBE THE PIKE AND

SAZAN:

carnivorous, an enormous mouth, a powerful tail, blunt teeth, a soft dorsal fin, sensitive feelers, sharp teeth, a weak tail, to dart forwards, to attack, to crush the shells, long slender body, a small head, broad and thick, vegetable matter.

IV. FILL IN THE BLANKS WITH THE WORDS BELOW THE TEXT
AND TRANSLATE IT:

Curiosities of coral communities, Australian red sea ... glow as if electrified. They are not really .... These are inch-long marine ..., belonging in the ... Amaryllis. The sea fleas ... on lacelike bryozans and polyps of soft ... . Their ... colour may warn fish and other... to avoid a bad-tasting meal.

* predators, coals, invertebrates, fleas, arresting, senus=species, graze, fleas.

Text 7.

Sardine.

Sardine is a member of the herring family and an important food fish. The word «sardine» refers to several groups of fishes. But it is used mainly for such species as the Pacific sardine, the South African sardine, and the European sardine, or pilchard. Other members of the herring family, including sprats and young Atlantic herring, are also sold as sardines.

The name «sardine» was given to the fish because they were first caught near Sardinia, an Italian island in the Mediterranean Sea.

Sardines live in warm ocean waters near the shores of almost all the continents. They are especially plentiful on the coasts of Japan, north-western Africa, and western South America. Sardines average 23 to 30 centimeters in length and about 115 grams in weight. The upper part of their body is blush-grey, and the lower part is silvery. Adult sardines usually swim in large shoals. They feed on small animal and life called plankton.

Most sardine fishing takes place on moonless nights. The movement of sardines disturbs tiny organisms that live near the surface of the sea.

It causes these organisms to produce light by means of a chemical reaction. This light called bioluminescence reveals the presence of sardine schools. Most sardines are caught with a special type of net called a purse seine.

The annual sardine catch worldwide totals about II million tons. Peru is the world's leading sardine-fishing nation, followed by Chile and Japan,

Cans of sardines are a familiar sight on supermarket shelves. Canneries precook sardines and remove part of their natural oil and moisture. Industry uses sardine oil in such products as linoleum, paint and varnish. Some sardines are made into fish meal, which is used in animal feed and fertilizer. Small sardines are used as bait in commercial tuna fishing.

VOCABULARY:

(to} catch - (ловитн), улов fish meal -рибна мука fertilizer - добриво bait - наживка average - середнє число purse seine - гаманцевий невід school - зграя

herring - оселедець

shore - берег

plentiful - багатий

to disturb - турбувати

to produce light - світитися

by means of- за допомогою

net - сітка

I. ANSWER THE FOLLOWING QUESTIONS:

1. What fish family does sardine belong to?

2. What is the origin of the word «sardine»?

3. When does sardine fishing take place?
-i. What do sardines feed on?

5. Where do the people use sardines and what for?

H. FIND THE ENGLISH EQUIVALENTS TO THE FOLLOWING WORDS:

зграя, улов, самець, самиия, рух, наживка, щорічний, волога, масло, ловити, cітка, узберіжжя, видаляти, добриво, турбувати.

III TRANSLATE INTO ENGLISH:

1. Щука відноситься до хижаків.

2. Вона поїдає Інших риб.

3. Міцний хвіст допомагає щуці швидко плавати за своєю добичею

4. Сардина живе в теплих водах океана, недалеко від берега.

5. Сардина харчується планктоном.

6. Вилов сардини відбувається безлунними ночами.

IV. ARRANGE THE FOLLOWING WORDS IN PAIRS OF SYNONYMS:

tiny, school, small, feed on. shoal, eat, various, learn, main, different, prime,

study.

V. READ THE FOLLOWING ENGLISH WORDS AND FIND THEIR UKRAINIAN EQUIVALENTS IN THE RIGHT COLUMN

shoal - вплив nostril - звичка isthmus - ніздря silt - харчуватися disturb - водорость worm - хижий habit - перешийок feed on - мул

weed - турбувати fin - черв'як carnivorous - плавник influence - зграя capture - хвороба disease - добич prey - захворювання

Text 8.

Shrimp.

Shrimp are delicate shellfish related to crabs and lobsters. Shrimp are a popular food. Shrimp are found in fresh and salt water in nearly all parts of the world. Some species live near the shore, where they hide in mud or sand by day and feed by night. Others swim about in groups in deep, cold water. A shrimp generally swims forward, it can swim backward by flipping its fan-shaped tail.

Most shrimps have grey, brown, white or pink bodies. But some are red, yellow, green or blue. Some can change color to match their surroundings. Many species are luminescent (light - producing).

The smallest shrimp are less than 2,5 centimeters long. Some giant freshwater species grow over 30 centimeters long and have feelers equally long.

Larger shrimps are sometimes called prawns.

Many small shrimp eat plankton (small drifting plants and animals). Large shrimps feed on material on the sea bottom. Shrimps, in turn, serve as an important food for fish and other water animals. Some shrimps help «clean» fish by feeding on parasites from the gills, mouth and scales of the fish.. Other shrimps closely resembie these shrimps, but, instead of eating parasites, they take bites of the gills and flesh of the unsuspecting fish.

Most shrimps have 19 pairs of jointed legs, feelers, and other appendages. Head and chest have two pairs of feelers, which taste the water to locate food, a pair of appendages serve as jaws, five pairs of appendages handle food, and five pairs are walking legs. The abdomen has five pairs of swimmerets, which are used in swimming and reproduction. It also has a pair of appendages that form part of the shrimp's tail.

Some kinds of shrimp have claws on their two front pairs of walking legs. A shrimp uses its claws to gather food, to fight, and to dig burrows in which to hide. The pistol shrimp makes a sound like a gunshot by snapping one of its claws.

A shrim's shell is hard and stiff and encloses the animal's body. The only way the shrimp can grow is to molt (shed its shell) and grow a new shell, A shrimp molts many times during its life. A new. larger shell hardens after each molt. If any appendages have been lost, new ones develop during the course of several molts.

Various species of shrimp have different life cycles. Some live a year at others may live five years or more. Some females carry their eggs on their swimmerets until they hatch. Other lay their eggs and swim away. Some shrimps do not swim about but live in burrows in sand or mud.

Members of the groups shrimp, the pandalids, all begin life as males. At about 2 years of age, they change to females.

Fishing crews use pouch-shaped nets called trawls to catch shrimp. Boats drag the trawls across the bottom of the sea or river mouth. The catch is frozen or canned quickly because fresh shrimp spoil easily.

The United States leads the world in shrimp production. About half the world's catch comes from Asia. People in Japan raise shrimp in large tanks or ponds.

VOCABULARY:

appendage - придаток abdomen - брюшина

claw - клешня
to dig burrow - рити нору
molt - линяти

Shrimp - креветка

shell - панцир; раковина

lobster - омар

to match - мати схожість

gills - зябри

I. ANSWER THE FOLLOWING QUESTIONS:

1. What is shrimp?

2. What do shrimps usually feed on?

3. Do shrimp serve as an important food for fish and other water animals?

4. How do shrimp grow?

5. How do fishing crews catch shrimp?

II. FIND IN THE TEXT THE ENGLISH EQUIVALENTS TO THE FOLLOWING WORDS:

вирощувати, улов, заморожувати, самка, самець, судно, твердий, сховатися, використовувати, розмішувати, пробувати на смак, в свою чергу, змінювати колір, зябри, голова, хвіст, вид, пісок, відкладати ікринки, єдиний засіб.

III. TRANSLATE INTO UKRAINIAN:

1. The most common kind of the United States food shrimp, hatch from eggs laid
in the ocean up to 160 kilometers offshore.

2. A newly hatched peneid (пенеда) looks like a tiny pear with legs.

3. It changes shape several times until, after two to four weeks, it looks like a
miniature adult.

4. Young peneid shrimp move toward shore as they develop, but SO per cent or
even more may be eaten by sea animals along the way.

5. After about five to seven months of rapid growth, the shrimp begin a two-
month trip back to deeper water,

6. They breed in deep water, and each female lays 500 000 to 1 000 000 eggs.

7. Scientists believe that most of the adults die soon after the eggs are laid.

IV. FIND IN THE LIST BELOW ANTONYMS TO THE FOLLOWING WORDS:

forward, tiny, fresh, small, hard, stiff, live, easy, quickly, adult, far

giant near, slowly, young, die. difficult, flexible, large, soft, salt, backward.

Text 9.

Salmon.

Salmon is one of the most important food sport fishes. Every year throughout the world eat millions of cans of pink or red salmon.

Most of the salmon sold comes from five species that live in the coastal waters of the North Pacific Ocean. A sixth Pacific species lives only in northern Asian waters. One species, called the Atlantic salmon, lives in the North Atlantic Ocean. Ibis fish is actually more closely related to the trout to the Pacific salmon.

Salmon are born in a freshwater stream, and most of them spend part of their life in the salt water of the ocean. Then they return to the freshwater stream of their birth to spawn. Pacific salmon spawn only once and soon afterward. Atlantic salmon may swim back to the ocean after spawning and return to fresh water to spawn as many as three more times. Adult salmon swim upstream at spawning time. The fish are famous for their fighting spirit. They battle rushing currents and leap across swirling rapids and over waterfalls as high as 10 feet (3 meters). When hooked, they struggle furiously to escape.

Most salmon spawn in summer or autumn after swimming upstream as far as 3 kilometers from the ocean. The journey may take several months. Female salmon lay . their eggs in the gravelly bed of a shallow stream. A male salmon stands guard as the female turns on her side and digs a nest in the gravel by swishing her tail back and forth. The female lays her eggs in the nest, and the male fertilizes them with sperm.

The female then swims forward a short distance, digs another nest, and lays more eggs. The male and female may repeat the spawning process several times.

The eggs hatch after three or four months, and the baby salmon lie hidden in the gravel for several weeks. They feed on a yolk sac. Some kinds of salmon leave fresh water for the ocean immediately after they come out of the gravel. Other species may spend up to three years in fresh water. They eat insects and small animal life called

plankton.

Only a small percentage of the salmon reach the ocean from fresh water. Fish and birds eat some salmon, and polluted water kills others. Salmon that reach the ocean live there from six months to five years. During this period they feed on shrimp, squid and small fish. Scientists know that most salmon return for spawning to the same stream in which they hatched. Many scientists think salmon navigate in the sea by somehow sensing the magnetic field of the earth and the currents of the ocean. After reaching the coast, salmon apparently remember the odor of their «home» stream and follow this scent.

Salmon stop eating after reaching fresh water to spawn. They live off fat stored in their body. As the fish travel upstream, their shape and colour change.

Commercial fishing crews catch salmon as the fish leave the ocean to journey upstream. Most salmon are caught in nets. Some salmon is sold fresh, frozen or smoked, but most is canned.

VOCABULARY:

to escape - утекти to reach - досягати odor - запах

sense - чуття

to dig -виконувати

throughout- усюди

to relate - мати відношення

to return - повертатися

to be famous for - бути відомим

hook - крюк, гачок

furious - несамовитий, лютий

I. ANSWER THE FOLLOWING QUESTIONS:

1. Where are salmon usually born?

2. Most of the salmon spend part of their life in the salt water, don't they?

3. What are salmon famous for?

4. When do salmon spawn?

5. Where do salmon female lay their eggs?

6. What does a baby salmon feed on?

7. What do salmon live off after reaching fresh water to spawn?

II. FIND THE EGLISH EQUIVALENTS TO THE FOLLOWING WORDS:

нерест, розвиток, відомий, харчуватися, дорослий, течія, почуття, планктон, свіжий, морожений, копчений, досягати, узбережжя, форма тіла, подорожувати, продавати, вчений, промисловий, комаха.

IV. R£AD THE FOLLOWING EGLISH WORDS AND FIND THEIRUKRAINIAN EQUIVALENTS IN THE RIGHT COLUMN.

spawning- гніздо

fat- гравій

yolk sac - запах

coastal - нерест

hatch - жир

fin - прибережний

odor - запліднювати

Female -течія Male - креветка current - самиця shrimp - форель trout - самець nest - жовтковий мішок gravel - плавник fertilize - вилуплятися

V. TRANSLATE INTO UKRAINIAN WITHOUT USING A DICTIONARY:

1. Seahorse is a small fish that is so named because its head resembles that of tiny
horse.

2. A seahorse's large swim bladder holds air and enables the fish to stay at the a
certain depth.

3. The pectoral fins located at the side of the seahorse's head look like a pair of
ears.

4. Seahorses have an unusual way of reproducing. The male has a special pouch
(мішок) in which the female lays from dozens to hundreds to eggs. The male
later releases tiny young.

5. Seal (тюлень) is a sea animal with a body shaped like a torpedo.

6. Seals are excellent swimmers and spend much time in the water, but they give
birth to their young on land.

7. Seals feed on various marine animals, primarily fish and squids..

НІ. FILL IN THE BLANKS WITH THE WORDS GIVEN BELOW:

1. Adult salmon swim ... at spawning time.

2. During ... the salmon female lays a total of 2 000 to 10 000 eggs.

3. All male salmon develop a ... snout.

4. Atlantic salmon is not nearly so ... as Pacific salmon.

5. Coastal waters, lakes and rivers in many ... of the world are ... with salmon.

'spawning, parts, plentiful, hooked, upstream, stocked

Text 10.

Marine aquaculture.

Marine aquaculture or mariculture - is relatively new direction in fishery activities at the coastal Ukrainian zones of the Black Sea and the Sea of Azov.

With this purpose breeding the fish and release it into the numerous estuaries of the Black Sea and the Sea of Azov, such as sturgeon, mullet, sturbotplaice and other

species. Scientific and research and experimental works on development of technology of mariculture have been initiated by the new experimental plantations, farms, completes for breeding, catching and processing of shellfish, crustacean and seaweed.

Of all the molluses living in the Black Sea, the most important for fisheries are mussels, oysters. Natural mussels in the Black Sea live in big colonies clustering on the surface of large stones. They are found every where: along the walls of embankments, ports.

At the present time a mariculture development in the coastal waters appears more profitable, very promising and competitive.

IV. PUT INTO ENGLISH:

Морська аквакультура - відносно новий напрямок у рибному промислі. Він успішно розвивається у прибережних зонах Чорного та Азовського морів. Передові технології вирощування риб були запроваджені у багатьох рибних господарствах та комплексах для вирощування, ловлі і переробки молюсків, ракоподібних І морських водоростей. Найбільш важливе місце в цій галузі займають устриці та мідії. В теперішній час розвиток морської аквакультури стає прибутковим і досить обіцяючим.

V. CREATIVE WORK.

Make up ail possible questions to discuss fishery activity m Ukraine nowadays.

VOCABULARY:

shellfish - молюск

crustacean - ракоподібні

seaweed - морська водорость

oyster - устриця

sturgeon - осетр
mullet - кефаль

sturbotplaice - камбала-глось

I. GIVE THE ENGLISH EQUIVALENTS TO THE FOLLOWING:

Моркультура, рибний промисел, вирощувати рибу, ловля ракоподібних, переробка мідій та молюсків, прибуткова галузь, розвиток технологій, запроваджувати научні розробки.

II. WRITE OUT THE NAMES REFFERING TO THE TOPIC «MARICULTURE»:

cow, snake, oyster, mullet, breed, shellfish, cluster, sturbotplaice, mussel, molluse, estuary, sturgeon, species, colony, seaweed, catching, crustacean, moisture.

ІП. COMPLETE THE SENTENCES:

1. Marine aquaculture is ....

2. Technologies on mariculture development have been initiated ....

3. For fisheries the most important moluses are ....

4. New direction in fishery activities ....

Supplementary Part.

Text 1. COMPUTERIZATION OF CURRENT

[CHTHYOPATHOLOGICAL STUDIES IN UKRAINE

Computers are an essential tool that makes the work of scientist more efficient andoperative in implementations of the results.

In ichthyopathology computers are used for compilation and analysis of data on fish parasite invasions and diseases. These data are necessary for quick estimation of epizootic situation, planning treatment and making decisions on expediency of fish transportation.

It is compatible practical work to use computer database on medicines and

prophylactic measures to be applied.

It assists in choosing efficient methods for disease treatment and prophylaxis-Computerization can help in diagnosis of different diseases. Elaboration of

disease determination is the future task for ichthyopathology.

Currently the work on computerization of ichthyopathology is in progress in

UKRAINE.

Software on fish diseases in UKRAINE fisheries were developed at the

Laboratory of fish diseases. First steps were done in creation of database on the

remedies used in ichthyopathology for prophylaxis and treatment offish diseases.

These first software should of cause be improved. Unfortunately this work is

complicated by difficulties in purchasing computer equipment and training of

specialists.

Text 2. FISH SMOKING AND THE ENVIRONMENT

Large-scale use of smoke within the food industry is no more than 50 years old. The growing population - and at least in the industrial nations, the increase in food supply that went with it-made food preservation increasingly important.

Development within the field of smoke process engineering over the last decades has moved the technology from the "open" systems of the past to "semi-closed" or "closed" systems.

Semi-closed systems generate the smoke outside the smoking chamber. Some smoke generators are specially constructed to produce processing smoke from sawdust. The sawdust is fed through a funnel onto a "glow plate" whose underside is within the hot air duct. Carrier air then introduces the generated smoke into the plant. During this process numerous organic compounds are produced which give the smoke its apical aroma. The level of harmful substances contained within the emissions produced is so high that the exhaust air has to be cleaned using a special technique. The most notable noxious compounds are carbon monoxide, phenols, acrolein. organic adds, tar

substances, formaldehyde and polycyclic aromatic hydrocarbons. Subsequent cleaning is usually carried out using special afterburners that heat the smoke about 800 to 85O°C and convert it to NOx and C02. This process involves additional equipment, the result of which is higher capital investment and running costs.

Other smoke generators utilise larger wood chips. The larger size allows greater airflow and thus higher temperatures can be generated. These higher temperatures lead to a different smoke composition. The tar content within the smoke rises, resulting in a darkercoloured smoke in combination with a stronger smoke flavour. This method of smoke generation involves relatively large quantities of tar which would seem to make it rather dubious from an environmental standpoint, in addition, the plants have to be thoroughly cleaned to remove the tar. This means that, besides the production of tar and waste air containing harmful substances, wastewater is also produced during the cleaning process. The composition of the waste air from the smoking process is similar to that produced during sawdust-based smoking. This means that subsequent waste air treatment is necessary here, too.

Text3. FISH SELECTION FOR RESISTANCE TO DISEASES

Yu. I. llyasov

All-Russian Research Institute of Freshwater Fisheries, Rybnoe, Dmitrov region. Moscow province, 141821. Russia

Works on selection for disease resistance cover the most spread and mass infections in salmon fishes, such as vibriosis, furunculosis, bacterial kidney disease, infectious pancreatic necrosis, viral hemorrhagic septicemia; in carp - infectious dropsy, swim bladder inflammation; in channel catfish - the viral disease; in European catfish -septicemia; in American oyster - haptosporidiosis.

The possibility to increase fish disease resistance by selection (genetic prophylaxis) does not diminish the significance of methods of sanitation and disease treatment developed by ichthyopathological science. But there are a number of diseases for which prophylaxis selection and genetic methods are preferable. To this category of diseases should be referred the acute infections (infectious dropsy, swimm bladder inflammation in carp), fast infections (fin rot in eel), constitutional diseases (yoke sac dropsy in Arctic salmon), highly specific parasitic diseases (dactylogyrosis in herbivorous fishes).

A number of fundamental reports appeared in literature on problems of hydrobiont selection for increased diseases resistance. Analysis of the literature data, as well as our own long-term work on carp selection for increased resistance to infectious dropsy allowed us to formulate a strategy of aquacuiture object selection in the nearest future, as well as a tactical solution of tasks for achievement of the final purposes of selection programmes envisaging formation of resistant breeds of fish and other hydrobionts.

In case of viral diseases the problem of virus carrier state in resistant breeds and their role in infection spreading must be of paramount scientific and applied

evolutionary development;

- validation of efficacy of different treatments and their elimination rates from fish, including elaboration of therapeutic doses of drugs and limited permissible concentration of toxicant.

significance in this strategy. For effective solution of this problem it is worthwhile to use methods of nucleic add hybridization or PCR for detection of virus carrier state.

In the development of long-term selection programmes with the main meaning of increased disease resistance, it is expedient to determine experimentally or theoretically the necessary and sufficient level of resistance in order to avoid any negatively correlated effects of the one-side selection.

As to the tactical aspect, it is necessary to begin selection work from determining genetic parameters conferring the fish the increased disease resistence and from the choice of adequate selection methods.

Text 4. DETERMINING THE PHYSIOLOGICAL STATUS OF FISHES USING HAEMATOLOGICAL PARAMETERS

N.A. Golovina

All-Russian Research Institute of Freshwater Fisheries, Rybnoe, Dmitrov region, Moscow province, 141821, Russia

Study of the functional condition of blood, one of the main systems offish, shows that blood plays an important role in adaptation of fish to their environmental conditions. Morphology of cells, their quantitative parameters, and their seasonal and age dynamics are specific peculiarities of blood. Blood fulfills the following functions: respiratory, defense, tropical, etc., which predetermines the use of blood in diagnosis of the physiological condition offish, especially in aquaculture conditions.

Generalizations of our data on blood of different fish species, such as carp, rainbow trout, Caspian trout, and sturgeon allows us question hematological standard parameters, by using qualitative and quantitative indices. The first qualitative indices concern how blood cell morphology changes in fish. The second indices concern the characterization of the seasonal and age related dynamics of the hematoiogical status of fish.

Using a united and original approach to standard cyto-morphological and morpho-physiological methods, we solved fundamental and applied problems concerning the practical use of hematology for diagnosis and prophylactic treatment of diseases in the freshwater aquacuiture. The following represents the most important of the problems addressed:

- value of blood parameters for diagnostic purposes and for determining the
physiological status of fish, and elaboration of these principles for using in early
diagnosis of disease;

- study of the peculiarities of pathogenesis of disease organisms;

- elaboration of objective criteria of parasite pathogenesis by means of the
specific index of invasion intensity, and using this index to aid in setting limits
between harmful parasite infestation which should be treated and those which
may be considered relatively harmless and with no need of treatment;

- use of hematological parameters for evaluation of interaction of fish with
parasitic systems and for detection of the state of homeostasis. as result of their

Text5. SELECTIVE BREEDING IN CONDITIONS OF PERMANENT ENVIRONMENTAL POLLUTION

V.M. Simonov, Yu.l.llyasov

All-Russian Research Institute of Freshwater Fisheries, Rybnoe, Dmitrov region, Moscow province, 141821, Russia

The data on presence in water, river sediments and macrofits of the most stable toxicants show the permanent pollution of fishery reservoirs in Azov-Kuban region. Development of new fish breeds with increased productivity and survivability under conditions of degradation of ecological systems will aid to get success in achieving objectives standing before fish industry.

In general, understanding mechanism of stress resistance of organisms belonging to various genetic strains has one important aspect. It relates to search for methods for purposeful influence on genetic system aimed at generating stress resistance in organisms, which has had no such a feature before.

Natural populations of certain organisms inhabiting polluted regions in some cases started were found to have increased resistance to toxicants. It may be the results of adaptive evolutionary changes.

Estimation of tolerance to determine genetic distinctions between nine families of silver carp (Hypophihaimichthys molitrix Val.) was done by testing survivability under contrasting environmental conditions. The outcome of dispersion analysis showed that non-additive gene interaction prevails in the system of genetic control of stability with possible mother's effect. The quantitative estimate of tolerance of the silver carp families was obtained from the results of probitanalysis, which permitted to recognize susceptible families and families resistant to hexachlorciclohexan action. Testing fish on resistance to oxygen deficit (hypoxia) showed that families resistant to low oxygen level were also resistant to the toxicant. These results let assume the existence of nonspecific resistance in the compared groups both to hypoxia and toxicants and its genetic basis.

The main task of selection when species are being bred is that the fish should be genetically adapted to both natural or artificial environmental conditions.

Text 6.

PARASITE

Nobody knows how many kinds of parasites there are. They range in size from the smallest virus, inconceivably small at one one-thousandth of a micron, to whale tapeworms a hundred feet long. Some, like ticks, fleas live on the surface of their

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hosts. Other - trematodes, tapeworms, nematodes - live within, denizens of blood, intestines, liver and heart.

Many are specialists. The so-called pork tapeworm can mature only in humans. One kind of trematodes lives' only on the first gill arch of one species of cod. The green parrot of Mexico harbors at least 15 species of feather mites; each lives on a particular part of a particular feather on the bird's body. Fleas, ticks and leeches are usually more catholic in their choice of hosts, feeding on the blood of a variety of animals. A rat flea deprived of a rat will happily settle on a bat.

Certain parasites are innocuous. Two varieties of mites five harmlessly on the landscape of the human face, tucked into hair follicles of the forehead and cheeks. However, many parasites pester, maim or kill the animals they infect. Several of those:

hookworms, little leechlike -vampires of the intestinal tract, suck the blood of a billion people a year and kill perhaps 100,000. Blood-dwelling trematodes infect 200 million people, sometimes causing severe disease of the gastrointestinal tract, bladder and liver.

For humans, the worst offenders are protozoa's, the parasites that cause malaria. Nearly half a billion people are infected with malaria, and each year as many as two million die from the disease, mostly in tropical Africa.

Plant parasites such as tropical mistletoes send their roots deep into the vascular system of their green hosts. Or kleptoparasites, animals that steal or pirate food, and social parasites, which exploit the labors of other species.

What all these things have in common is their way of life. Parasites are not a natural group, like birds or animals or mammals, but a collection of organisms that live at the expense of other organisms, relying on them to survive and reproduce and usually doing harm in the process.

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