Fish are classified according to a number of characteristics: lifestyle, fishing season, sex, physiological state, fatness, feeding pattern, length or weight.
AB - fishing length of fish; AB - standard size; 1 - gill cover; 2 - hard dorsal fin; 3 - soft dorsal fin; 4 - caudal fin; 5 - lateral line; 6 - anal fin; 7 - anus; 8 - ventral fins; 9 - pectoral fins
The length of the fish is measured in a straight line from the top of the snout to the beginning of the middle rays of the caudal fin (Fig. 20). Some small and low-value fish are classified as small fish I, II or Group III. A number of fish species listed in the standard are not subdivided by length and weight. The minimum length of fish that can be caught is set by fishing regulations and international conventions.
IN commodity practice fish are classified by species and families.
A species is a collection of individuals occupying a certain geographical area and having a number of inherited characteristics that distinguish this type from related species. Species that are similar in a number of characteristics are grouped into genera, and the latter into families.
IN trading practices Classification of fish into families is carried out mainly by external characteristics. Strictly scientific classification of fish into families is carried out according to many characteristics. Characteristics of the main characteristics of the families of fish most commonly found in commercial practice are given below.
Herring family has a laterally compressed body, covered with easily falling scales. There is no lateral line. There is one dorsal fin, the caudal fin has a deep notch. Herrings of commercial importance are: Atlantic, Pacific, Danube, Don, Dnieper, Kerch, Volga, Chernospinka, Azov belly, Herring, Sardines, Sardinella, Sardi-nops (Ivasi); sprat: Caspian, Baltic (sprats), Black Sea, Tyulka.
Anchovy family has a cigar-shaped body, similar in size to small herrings. This family includes the Azov-Black Sea Hamsa and Anchovy.
Sturgeon family has an elongated fusiform body, with five rows of bone formations - bugs: two abdominal, two thoracic, one dorsal. Elongated snout, With four antennae. The dorsal fin is single, the caudal fin is unequally lobed. Of commercial importance are: beluga, kaluga, sturgeon, thorn, stellate sturgeon, sterlet. By crossing beluga and sterlet, Soviet scientists obtained a bester, which is bred in reservoirs.
Carp family has a tall, laterally compressed body, covered with tightly fitting scales, sometimes naked. The dorsal fin is one, soft, the lateral line is well defined, the teeth are pharyngeal. This family includes fish of inland waters: carp, carp, crucian carp, roach, roach, ram, bream, white-eye, bluefish, barbel, silver carp, grass carp, buffalo, vimba, shemaya.
Salmon family has a tall body, laterally compressed, covered with small scales. There are two dorsal fins, the second is adipose. The lateral line is well defined. Chum salmon, pink salmon, sockeye salmon, Chinook salmon, Caspian salmon, salmon, trout, whitefish, vendace, muksun, and omul are of commercial importance.
Family smelt has an oblong body shape, with easily falling scales, and an incomplete lateral line. There are two dorsal fins, the second is adipose. Main species: European smelt, smelt, capelin.
Perch family has two dorsal fins, the first is spiny, the anal fin has three spiny rays, the lateral line is straight, and there are transverse stripes on the sides. Common species: perch, pike perch, ruff.
Horse mackerel family has a flattened body shape. The lateral line has a sharp bend in the middle, and in some species is covered with bony spines. There are two dorsal fins, the first is spiny, the second is soft and long. There are two spines in front of the anal fin. The tail stalk is thin. The Azov-Black Sea mackerel, oceanic mackerel, trevally, seriola, pompano, lichia, and vomer are of commercial importance.
Cod family are divided into subfamilies of cod-like and burbot-like. The former have three dorsal and two anal fins, the latter have two dorsal and one anal. This sea fish, with the exception of burbot. They have a well-defined lateral line. The pelvic fins are located under the pectoral fins or in front, and many representatives have a barbel on the chin.
The body shape is close to torpedo-shaped. Cod, haddock, navaga, pollock, pollock, blue whiting, burbot, and cod are of commercial importance.
Mackerel family has an elongated fusiform body and a slender caudal peduncle. There are two dorsal fins; behind the second dorsal and anal fins there are four to seven additional fins. Black Sea, common, and Japanese mackerels are of commercial importance. Mackerels are sold under the names “Azov-Black Sea mackerel”, “Far Eastern mackerel”, “Kuril mackerel”, “Atlantic mackerel”.
In terms of body shape and arrangement of fins, tuna, bonito, and mackerel fish are similar to mackerel; the latter have one dorsal fin and additional fins.
Flounder family has a flat body, flattened from the back to the abdomen, the eyes are located on one side of the head. Dorsal and anal fins along the entire length of the body. The commercially important halibuts are black, common, and arrow-toothed; sharp-headed and river flounder.
Of the fish of other families, the following are of commercial importance.
Groupers golden, beaked, Pacific from the scorpionfish family have a large head, an oblong, laterally compressed body, often red in color, one dorsal fin, usually spiny in the front.
Catfish striped and spotted from the catfish family
They have one long soft dorsal fin, a large round head, and the body in the back is laterally compressed.
Terpugi northern, southern, toothy have a spindle-shaped body, one spiny dorsal fin, highly developed anal and pectoral fin And.
Ice fish from the white-blooded family, it has a large head with an elongated snout, two lateral lines, the color is light green, the blood is colorless, as it contains copper instead of iron.
Butterfish and butterfish small fish from the Stromatoid family they have a flattened high body, one soft long dorsal fin of the same size and shape as the anal fin, the lateral line follows the curve of the ridge.
Marbled and green notothenia, squama, toothfish from the nototheniaceae family have a large head, two spiny dorsal fins, a long anal fin, large pectoral fins, and the body is thickened in the front.
Croaker, captain, umbrina- fish from the croaker family, have a high body, a humpbacked back in front, one dorsal fin, divided by a deep notch, the front part is spiny, the lateral line is well defined.
Macruruses from the grenadier family they have an elongated body that tapers off at the tail in the form of a thread. There are two dorsal fins.
Other types of fish that are caught are catfish, pike, lamprey, eel, gobies, argentina, mullet, eelpout, pristipoma, bluefish from families that have similar names, and sea bream from the brahmin family; merrow, rock perch - from the serranaceae family.
Chapter 8. Fish products8.1. Body structure of fish and types of fish cutting
Test 8.1.1. Body structure of fish
Name the body parts of the fish marked in the picture.
Figure 8.1. Structure of fish
Test 8.1.2. Types of fish cutting
Select from the list of cutting types the type that matches each definition.
Definitions:
1. a fish in which the pectoral fins have been removed along with the adjacent part of the abdomen and part of the entrails;
2. fish from which the entrails and caviar or milt have been removed through a cut in the abdomen;
3. a fish in which the head with a bunch of entrails has been removed, without a cut on the abdomen;
4. a fish in which the head, belly and entrails have been removed. The head may be left;
5. fish from which the gills or gills and part of the entrails have been removed;
6. decapitated or headless gutted fish from which the caudal fin has been removed;
7. headless gutted fish, cut along the spine into two longitudinal halves, from which the fins, tail part, abdominal part, spine, humerus and rib bones have been removed;
8. longitudinal halves, cut from the fish carcass parallel to the spine;
9. part of a fish carcass, sliced crosswise;
10. The fish is cut along the belly with two longitudinal cuts: the first - from anus to the ventral fins, the second - from the ventral fins to the caltych (the part of the fish body located between the gill covers and pectoral fins). Gills, entrails, eggs or milt have been removed;
11. abdominal part of the fish;
12. fish, cut along the back along the spine from the upper lip to the caudal fin, from which the entrails, eggs or milk have been removed.
Types of fish cutting:
a) sidewall; b) gilled; c) chilled; d) piece; e) beheaded; f) reservoir; g) gutted; h) gutted salmon cut; i) back; j) fun;
l) carcass; m) fillet.
Note. This activity can also be used as a second-level constructive test if students are not given a list of types of fish cutting.
8.2. Main commercial fish families
Test 8.2.1. Fish families: external signs
(first level, test-ratio)
Establish the relationship between fish families and their characteristic external features.
Fish families:
1. flounder;
2. carp;
3. salmon;
4. perch;
5. sturgeon;
6. herrings;
7. mackerel;
8. catfish;
9. cod;
10. pike.
Distinctive external features:
a) the body is elongated, fusiform. There are two fins on the back. After the second dorsal fin and after the anal fin, additional small fins go towards the tail;
b) the body is spindle-shaped with small scales, there are two fins on the back, the first of which is ordinary, and the second is spiny;
c) the body is flat, the upper side of the body is with scales, the lower side is without scales, the eyes are located on the upper side of the body;
d) elongated, fusiform body with a clearly visible lateral line. They have three dorsal fins and two anal fins.
e) the body is oblong, covered with scales; there are no scales on the head. There is one regular fin on the back and an additional adipose fin closer to the tail;
f) the body is elongated, laterally compressed, the scales are small, the lateral line is not visible. Caudal fin with deep notch;
g) the body is slightly elongated, with most representatives of the family having a high thickened back. The scales are large with a clearly visible lateral line;
h) the body is large, without scales. Large head with a wide mouth and mustache;
i) the body is elongated with small scales, the snout is elongated, flattened from top to bottom, with sharp teeth. Body coloration is spotted. The dorsal fin is located closer to the tail;
j) an elongated body with an elongated snout, without scales, five rows of bone growths along the body. The caudal fin is asymmetrical.
Test 8.2.2. Fish families: representatives
(first level, test-ratio)
Select from a list of fish belonging to each of the named families.
Fish families:
1. flounder;
2. carp;
3. salmon;
4. perch;
5. sturgeon;
6. herrings;
7. mackerel;
8. cod.
a) roach; b) beluga; c) pink salmon; d) ruff; e) crucian carp; e) chum salmon; g) sea tongue; h) navaga; i) halibut; j) blue whiting; l) herring; l) sardine; m) stellate sturgeon; o) pike perch; n) sterlet; p) tuna; c) hake.
8.3. Live, chilled, frozen fish
Test 8.3.1. Live, chilled, frozen fish
1. Fish from which of the following families are not usually sold live?
a) mackerel;
b) carp;
c) sturgeon;
d) pike.
2. What color should the gills of a quality live fish be?
a) pink;
b) red;
c) yellowish;
d) whitish.
3. What factors do not affect the preservation of the quality of live fish when kept in aquariums in a store?
a) water temperature;
b) how busy the aquarium is;
c) composition of water;
d) availability of food.
4. What temperature does chilled fish usually have in the thickness of the muscles?
5. In what form is chilled fish not available?
a) uncut;
b) gutted with the head;
d) gutted and headless.
6. How is chilled fish divided depending on quality indicators?
a) first and second grades;
7. What temperature does frozen fish usually have in the thickness of the muscles?
a) not higher than - 25°;
b) not higher - 18°;
c) not higher than - 12°;
d) not higher than - 8°.
8. How is fish frozen in modern enterprises?
a) in bulk and in blocks;
b) individually and in blocks;
c) individually, in bulk and in blocks;
d) only in blocks.
9. How is frozen fish divided depending on quality indicators?
a) first and second grades;
b) highest, first, second grade;
c) first, second, third grades;
d) is not divided into varieties.
10. What determines the shelf life of frozen fish?
a) depending on the type of fish;
b) on the type of fish cutting;
c) on the method of freezing;
d) from all of the above.
Test 8.3.2. Live, chilled, frozen fish
1. Freshwater fish such as... (Name at least five types of fish).
2. The surface of live fish must be clean, with a thin layer of….
3. A weak fish, swimming on its side or belly up, is called....
4. The deadline for selling live fish in the store is ..., and fish ... in order to avoid water pollution.
5. Chilled fish is packaged in containers with….
6. A sour smell in the gills is allowed, which is easily removed by washing with water, in all chilled fish, except ....
7. Frozen fish is made in unglazed and glazed form. Glaze is...
8. Frozen fish, depending on quality indicators, is divided into first and second grades, the indicators are determined by .... (Specify when).
9. The consistency of frozen fish should be dense; in the second grade it can be ..., but not ....
10. If a block of fish is defrosted to 0° (to facilitate the separation of fish from each other), the sales period is reduced to ... days.
8.4. Salty fish
Test 8.4.1. Salted and dried fish
(first level, identification test)
Choose the correct answer from several options provided.
1. Which family of fish are not usually salted?
a) herrings;
b) perch;
c) salmon;
d) anchovies.
2. What is used for spicy salting of fish, besides salt?
a) only black pepper and bay leaf;
b) a mixture of various spices;
c) a mixture of various spices and sugar;
d) a mixture of spices, sugar and acetic acid.
3. What type of salting is called “special ambassador”?
a) sweet ambassador;
b) pickled salt;
c) spicy salt;
d) ambassador of especially valuable fish.
4. By what principle are salted herrings usually given a trade name?
a) by the size of the herring;
b) by the name of the fishing vessel;
c) by time of catch;
d) according to the habitat of herring.
5. How are salted herring divided depending on quality indicators?
a) highest, first, second grade;
b) first and second grades;
c) first, second, third grades;
d) are not divided into varieties.
6. Which salting method does fish have the densest consistency?
a) the consistency of the fish does not depend on the salting method;
b) wet salting;
c) dry salting;
d) mixed ambassador.
7. What determines the shelf life of salted fish?
a) on the type of container and packaging;
b) on the type of fish cutting;
d) from all of the above.
8. Which family of fish is most often used for drying?
a) carp;
b) mackerel;
c) herrings;
d) cod.
Test 8.4.2. Salty fish
(second level, substitution test)
Fill in the missing words.
1. A solution of salt in water, used for salting, and the brine released from the tissues of the fish is called....
2. Depending on the nature of the changes that take place in the body of the fish during salting, fish are divided into....
3. Depending on the method of introducing salt into the fish, salting can be ....
4. Depending on the recipe, the salting can be... .
5. Depending on the container, the ambassador can be….
6. Depending on the salt content, salted herrings are divided into....
7. The consistency of salted fish depends on the salt content in it: the higher the salt content, the consistency….
8. At the salty ones salmon fish second grade, a slight odor is allowed ... ... on the surface.
8.5. Smoked fish and balyk products
Test 8.5.1. Smoked fish
(first level, identification test)
Choose the correct answer from several options provided.
1. Fish of which smoking method usually has a denser consistency?
a) cold smoked;
b) hot smoked;
c) the consistency of the fish does not depend on the smoking method.
2. Fish of which smoking method usually has a less salty taste?
a) cold smoked;
b) hot smoked;
c) the taste of fish is the same in terms of salinity.
3. What method of smoking is fish usually tied with twine?
a) cold smoked;
b) hot smoked;
c) both cold and hot smoked.
4. How is hot smoked fish classified by quality?
a) for the highest and first grades;
b) for first and second grades;
d) is not divided into varieties.
5. How is cold smoked fish classified by quality?
a) for the highest and first grades;
b) for first and second grades;
c) for the highest, first and second grades
d) is not divided into varieties.
6. What deviation from quality is allowed by the standard for hot smoked fish?
a) slight signs of dampness;
b) broken off heads and tail fins;
c) minor burns on the surface;
d) all of the above.
7. What deviation from quality is not allowed for cold smoked fish?
a) salt deposits on the surface;
b) light spots not covered by smoke;
c) iodine smell in marine fish;
d) flabby consistency.
8. Fish of which smoking method has a longer shelf life?
a) cold smoked;
b) hot smoked;
c) shelf life does not depend on the smoking method.
9. Why are only fish of certain families used to make balyk products (sturgeon, salmon, some ocean fish)?
a) for balyk products they are used only rare species fish;
b) for balyk products only fish with a certain body shape are used;
c) only fatty fish species are used for balyk products;
d) for all of the above reasons.
10. What other method of processing fish, besides cold smoking, is used in the manufacture of balyk products?
a) drying;
c) hot smoking:
d) all of the above methods.
Test 8.5.2. Smoked fish
(second level, substitution test)
Fill in the missing words and numbers.
1. They save fish with smoke or….
2. Depending on the temperature, smoking can be ... and ... .
3. Cold smoking of fish is carried out at a temperature of ... for ... .
4. Hot smoking of fish is carried out at a temperature of ... for ... .
5. The consistency of hot smoked fish should be juicy to dense, but it is allowed….
6. Cold smoked fish, depending on quality indicators, is divided into varieties: ....
7. The color of cold smoked fish can be from light golden to….
8. Smoked fish with the following defects is not allowed for sale: …. (Name at least three defects).
9. Balyk products are prepared from fish of the following families: ..., some oceanic fish are also used, for example, .... (Name at least two types of fish).
10. To prepare balyk products, such types of fish cutting as... are used. (Name at least three types of cutting).
8.6. Fish roe
Test 8.6.1. Fish roe
(first level, identification test)
Choose the correct answer from several options provided.
1. What size are sturgeon eggs?
a) 1 – 2 mm;
b) 2 – 4 mm;
c) 4 – 6 mm;
d) 1 – 6 mm depending on the size of the fish.
2. What size are salmon eggs?
a) 1 – 6 mm depending on the size of the fish;
b) 2 – 4 mm;
c) 3 – 6 mm;
d) 1 – 2 mm.
3. What determines the shade of the color of the caviar of fish belonging to the same family?
a) on the age of the fish;
b) from the time of spawning;
c) from the fatness of the fish;
d) depending on the type of fish.
4. What type of processing can sturgeon caviar be subjected to?
a) pasteurization;
b) sterilization;
c) ultra-pasteurization;
d) all of the above.
5. For what purpose is vegetable oil added to it when preparing salmon caviar?
a) to improve the taste of eggs;
b) to preserve the color of the eggs;
c) to prevent eggs from sticking together;
d) for all of the above.
6. What grades are canned granular salmon caviar divided into depending on quality indicators?
a) highest, first, second;
b) first, second;
c) first, second, third;
d) is not divided into varieties.
7. What grades are canned sturgeon granular caviar divided into depending on quality indicators?
a) highest, first, second;
b) first, second;
c) first, second, third;
d) is not divided into varieties.
8. What deviations from ideal quality are allowed in salmon and sturgeon caviar?
a) the presence of shells of burst eggs;
b) slight bitterness;
c) taste of sludge;
d) all of the above.
Test 8.6.2. Fish roe
(second level, constructive test)
Answer the questions.
1. What is the name of the organ in female fish that contains eggs?
2. At what period of a fish’s life are eggs mature?
3. What color and size is sturgeon caviar?
4. What color and size is salmon caviar?
5. What color and size are the caviar of other commercial fish, such as cod, pollock, pike, capelin, etc.?
6. Name the varieties of sturgeon caviar depending on the characteristics of its production.
7. Name the type of salmon caviar depending on how it is obtained.
8. What kind of caviar is called granular? What are the features of its preparation?
9. What are the features of the appearance of pressed caviar? What kind of eggs is it usually prepared from?
10. What kind of caviar is called breakdown? What are the features of preparing punchy delicacy caviar?
11. What requirements do the standards impose on appearance granular salmon and sturgeon caviar?
12. What is the main raw material for preparing artificial caviar?
8.7. Non-fish objects
Test 8.7.1. Non-fish objects
(first level, test classification)
Distribute the listed representatives into groups.
Groups:
1. crustaceans;
2. cephalopods;
3. bivalve mollusks;
4. echinoderms;
5. seaweed.
Representatives:
a) squid; b) cuttlefish; c) crabs; d) shrimp; e) krill; f) cucumaria; g) kelp; h) lobsters; i) mussels; j) scallops; k) sea urchins; l) lobsters; m) octopuses; o) crayfish; n) sea cucumbers; p) oysters.
Test 8.7.2. Non-fish objects
(second level, constructive test)
Answer the questions.
1. In what parts of the body is edible meat found in crustaceans?
2. What are large sea crayfish called?
3. Which crustacean is the smallest, and how is it used?
4. How are frozen shrimp produced depending on the type of processing?
5. What is the main raw material for making crab sticks?
6. What are the structural features of cephalopods?
7. What is edible in bivalves?
8. What do sea urchins eat?
9. What is the official name of “sea kale”?
10. How are substances obtained from seaweed, such as agar, agaroid, furcellaran?
8.8. Canned fish and preserves
Test 8.8.1. Canned fish and preserves
(first level, identification test)
Choose the correct answer from several options provided.
1. What type of fish are natural canned fish made from?
a) from raw fish;
b) from boiled fish;
c) from fried fish;
d) from all of the listed types.
2. Which fill is not used in manufacturing canned fish?
a) broth;
b) tomato sauce;
c) ghee;
d) vegetable oil.
3. What type of pre-treatment does fish undergo when making canned food “Sprats in Oil”?
a) drying;
b) frying;
c) smoking;
d) blanching.
4. Which of the listed names of canned food is divided into grades according to quality?
a) “Fish in jelly”;
b) “Sprat in tomato sauce”;
c) “Natural Far Eastern salmon”;
d) “Sprats in oil.”
5. What is the name of a defect in a metal can of canned food when the lid or bottom is deformed in the form of corners at the seam?
a) “bird”;
b) “tick”;
c) “rook”;
d) "forty".
6. How can an assortment mark be indicated on a metal can of canned fish?
a) letters of the Russian alphabet;
b) letters of the Latin alphabet;
c) a combination of letters and numbers;
d) all of the above images.
7. Which family of fish is most often used to make preserves?
a) flounder;
b) herrings;
c) perch;
d) mackerel.
a) -12…-18°;
Test 8.8.2. Canned fish and preserves
(second level, constructive test)
Answer the questions.
1. What are the main technological operations in the manufacture of canned food that make them suitable for long-term storage?
2. What methods of preliminary heat treatment of fish are used when preparing canned food? (Name at least three types of processing).
3. What are the names of canned food made from raw fish without additives or with the addition of spices?
4. What fillings are used in the manufacture of canned fish? (Name at least three types of fills).
5. Which internal organs Can fish be used to make canned food?
6. What types of canned food are made in the form of a homogeneous crushed mass? (Name at least two types of canned food).
7. What non-fish objects (seafood) are used to make canned food? (Give at least three examples).
8. What is the main difference between canned fish and vegetables and canned vegetables and fish?
9. What materials are containers used to make preserves?
10. Why should preserves, unlike canned food, be stored at a temperature no higher than 0°?
Fish classification(from Latin classis - category - class and ..., fication) - this is, simply put, the division of fish according to lifestyle, structural features, method of reproduction and appearance. There are a variety of classifications, and the aquarist needs to know the main ones.
Let's start with the fact that of all vertebrates, fish are the most numerous animals in terms of the number of species. If you combine all mammals, birds, amphibians and reptiles, then the number of their species will be less than fish, of which there are over 20 thousand species!
Fish inhabit almost all bodies of water globe. Through evolution, these animals adapted to various living conditions, which led to the emergence of many of their species. They are all combined into one general class"fish".
According to this system, the class of “fish” is divided into subclasses, subclasses, in turn, into orders, orders into suborders, suborders include superfamilies, superfamilies - families, families - subfamilies, subfamilies - genera, which already include species.
The Latin name for fish usually has a specific ending. Thus, an order, as a rule, ends in -formes, a suborder in -oidei, the name of a superfamily is written with the ending -oidae, a family ends in -idae, and a subfamily in -ini.
Other not specified systematic units fish classification do not have a specific ending and can end in different ways.
Fish classification is carried out as follows. Very similar species of fish in structure and lifestyle, as well as in their relationship, are combined into a genus. A genus, in turn, belongs to a subfamily, a subfamily belongs to a specific family, and so on. In some cases, species are also divided into subspecies.
The scientific name of the fish is indicated on the letter in two words. The first of these is the genus, and the second is the species name. In addition, the surname of the author who first described this species is indicated, as well as the year in which the description was created, if this year, of course, is known.
For example, the Latin name for fish zebrafish looks like this: Brachydanio rerio Hamilton-Buchanan, where Brachydanio is the name of the genus, rerio is the name of the species, and Hamilton-Buchanan, respectively, is the surname of the author.
In addition to the division described above, there are other fish classification. First of all, fish are always divided according to their habitat into marine and freshwater species.
Then, according to the method of reproduction, they are divided into viviparous and egg-bearing.
Next, and no less important, classify fish according to what is optimal for their life temperature conditions: Fish are warm-water, tropical and cold-water. Typically, aquariums contain tropical species, which are easiest to create suitable temperature conditions.
There is also fish classification according to their shape and structural features of the body. Usually, there is no separate Latin name in this case, but aquarists call different shapes types of fish by breeds.
For example, if the fish is called zebrafish veil, then such fish have elongated fins that look like a veil.
Besides, classify fish depending on the color form. In general, it might look something like this: black fork guppy, where guppy is the name of the fish species, black is the color of the body and fins, forked is the forked shape of the caudal fin.
Aquarists can call these same guppies, for example, “black prince,” although this species is exactly what scientists call it. fish classification not described or “patented”, but aquarists themselves came up with the name for the fish after they developed this form.
Pisces class- this is the largest group of modern vertebrates, which unites more than 25 thousand species. Fish are inhabitants aquatic environment, they breathe with gills and move with the help of fins. Fish are distributed in different parts of the planet: from high mountain reservoirs to ocean depths, from polar waters to equatorial ones. These animals inhabit the salty waters of the seas, found in brackish lagoons and estuaries large rivers. They live in freshwater rivers, streams, lakes and swamps.
External structure of fish
Main elements external structure The fish's bodies are: head, operculum, pectoral fin, ventral fin, trunk, dorsal fins, lateral line, caudal fin, tail and anal fin, these can be seen in the picture below.
Internal structure of fish
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Fish organ systems |
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1. Skull (consists of the braincase, jaws, gill arches and gill covers) 2. Skeleton of the body (consists of vertebrae with arches and ribs) 3. Skeleton of fins (paired - pectoral and abdominal, unpaired - dorsal, anal, caudal) |
1. Brain protection, food capture, gill protection 2. Protection of internal organs 3. Movement, maintaining balance |
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Musculature |
Wide muscle bands divided into segments |
Movement |
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Nervous system |
1. Brain (divisions - forebrain, middle, medulla oblongata, cerebellum) 2. Spinal cord (along the spine) |
1. Movement control, unconditioned and conditioned reflexes 2. Implementation of the simplest reflexes, conduction of nerve impulses 3. Perception and conduction of signals |
|
Sense organs |
3. Hearing organ 4. Touch and taste cells (on the body) 5. Lateral line |
2. Smell 4. Touch, taste 5. Feeling the direction and strength of the current, the depth of immersion |
|
Digestive system |
1. Digestive tract (mouth, pharynx, esophagus, stomach, intestines, anus) 2. Digestive glands (pancreas, liver) |
1. Capturing, chopping, moving food 2. secretion of juices that promote food digestion |
|
swim bladder |
Filled with a mixture of gases |
Adjusts immersion depth |
|
Respiratory system |
Gill filaments and gill arches |
Carry out gas exchange |
|
Circulatory system (closed) |
Heart (two-chambered) Arteries Capillaries |
Supplying all body cells with oxygen and nutrients, removing waste products |
|
Excretory system |
Kidneys (two), ureters, bladder |
Isolation of decomposition products |
|
Reproduction system |
Females have two ovaries and oviducts; In males: testes (two) and vas deferens |
The figure below shows the main systems internal structure fish
Fish class classification
Currently living fish are divided into 2 main classes: cartilaginous fish and bony fish. Important distinguishing features of cartilaginous fish are the presence of an internal cartilaginous skeleton, several pairs of gill slits that open outward, and the absence of a swim bladder. Almost all modern cartilaginous fish live in the seas. Among them, the most common are sharks and rays.
The vast majority of modern fish belong to the class of bony fish. Representatives of this class have an ossified internal skeleton. A pair of external gill slits are covered with gill covers. Many bony fish have a swim bladder.
Main orders of Pisces
|
Orders of fish |
The main characteristics of the detachment |
Representatives |
|
Cartilaginous skeleton, no swim bladder, no gill covers; predators |
Tiger shark, whale shark, katran |
|
|
Manta ray, stingray |
||
|
Sturgeon |
Osteochondral skeleton, scales - five rows of large bone plates, between which there are small plates |
Sturgeon, beluga, sterlet |
|
Dipnoi |
They have lungs and can breathe atmospheric air; the chord is preserved, there are no vertebral bodies |
Australian cattail, African scalefish |
|
lobe-finned |
The skeleton mainly consists of cartilage, there is a notochord; poorly developed swim bladder, fins in the form of fleshy outgrowths of the body |
Coelacanth (the only representative) |
|
Carp-like |
Mostly freshwater fish, there are no teeth on the jaws, but there are pharyngeal teeth for grinding food |
Carp, crucian carp, roach, bream |
|
Herring |
Most are schooling sea fish |
Herring, sardine, sprat |
|
cod |
A distinctive feature is the presence of a mustache on the chin; the majority are cold-water marine fish |
Haddock, herring, navaga, burbot, cod |
Ecological groups of fish
Depending on the habitat there are environmental groups fish: freshwater, migratory, brackish and marine.
|
Ecological groups of fish |
Main features |
|
Freshwater fish |
These fish constantly live in fresh water. Some, such as crucian carp and tench, prefer standing water. Others, such as the common gudgeon, grayling, and chub, have adapted to life in the flowing waters of rivers. |
|
Migratory fish |
This includes fish that move from sea water to fresh (for example, salmon and sturgeon) or from fresh water go to reproduce in salt water (some types of eels) |
|
Salty fish |
They inhabit desalinated areas of the seas and the mouths of large rivers: such are many whitefish, roach, goby, and river flounder. |
|
Sea fish |
They live in the salty water of seas and oceans. The water column is inhabited by fish such as anchovy, mackerel, and tuna. Stingrays and flounder live near the bottom. |
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A source of information: Biology in tables and diagrams./ Edition 2, - St. Petersburg: 2004.
Fish They are common in all types of reservoirs, from marine waters to the smallest ponds, eriks and rivulets. Tropics and eternal ice are also rich in unusual varieties of fish. In the reservoirs of Russia, aquatic inhabitants are very diverse and distinguished by their beauty. In the territory Russian Federation there are more than 120 thousand rivers, about 2,000,000 lakes, 12 seas, 3 oceans, and all of them are habitats fish. Even in fresh Russian reservoirs, over 450 animals have adapted to live. fish species, and many live permanently, and some arrive temporarily until a certain period.
general information
Based on the presence and nature of the rays in the fins of most bony fishes, a fin formula is compiled, which is widely used in their description and definition. In this formula, the abbreviated designation of the fin is given in Latin letters: A - anal fin (from the Latin pinna analis), P - pectoral fin (pinna pectoralis), V - ventral fin (pinna ventralis) and D1, D2 - dorsal fins (pinna dorsalis). Roman numerals indicate the numbers of prickly rays, and Arabic numerals indicate the numbers of soft rays.
The gills absorb oxygen from the water and release carbon dioxide, ammonia, urea and other waste products into the water. Bony fish have four gill arches on each side.
Gill rakers are the thinnest, longest and most numerous in fish that feed on plankton. In predators, the gill rakers are sparse and sharp. The number of rakers is counted on the first arch, located immediately under the gill cover.
The pharyngeal teeth are located on the pharyngeal bones, behind the fourth branchial arch.
