Method of making animal specimens

Method of making animal specimens

Mammalian specimens are one of the important materials in zoology research, and they are also the precious wealth of our country. Can be preserved for a long time and serve scientific research, teaching, exhibition and exhibition. Can be made into fake skinning specimens, bone specimens, liquid immersion specimens, appendages and other specimens according to needs. The tools and methods needed to make various specimens are described as follows.

1. Stripping tools: scalpel, dissecting scissors, bone scissors, long tweezers (sharp, with no serrations in the front end), dissecting disk or plastic sheet, thin lead wire or bamboo chopsticks, brain spoon (take a piece of lead wire, and mash the front end into a spoon shape), needle, thread, cotton, bamboo wire, and preservative mixed with arsenic trioxide and alum.

2. Before measuring the specimen, it is an essential step to measure the relevant parts of the specimen, and only by obtaining accurate data can the species be better identified. Measuring tools and articles include steel tape measure, ruler, label and collection book. The measurement includes the following items (Figure 3- 1). Weight: the total weight of an animal's body; Body length: snout to anus, snout to tail base of large animals; Tail length: the length from tail root to tail end (except tail hair); Length of hind foot: from the last end of tarsal joint to the front end of foot (except claw), ungulates should measure the front end of hoof; Ear length: the length from the base to the top of the ear shell (except the tufts). Large mammals also need to measure shoulder height (from the midline of the shoulder back to the front fingertip), chest circumference (the maximum circumference of the chest behind the front leg), waist circumference (the minimum circumference of the front waist of the rear leg) and hip height (from the midline of the hip back to the toe tip of the rear toe) (Figure 3-2).

Step 3 make animal specimens

(1) Small mammal specimens can be divided into fake peeled specimens for scientific research and ecological specimens for teaching and exhibition.

① Pseudodissection specimen (taking rats as an example)

Skinning: put the mouse corpse on the dissecting disc and plastic cloth, and cut the skin along the front of anus in the middle of abdomen to the back of sternum with a scalpel. Don't use too much force during the operation, so as not to cut the abdominal cavity and pollute the fur. Then use the back of a knife or tweezers to separate the skin and muscles connected with the incision and hind limbs, respectively push the hind limbs out of the incision, cut the knee joint and remove the muscles on the calf (Figure 3-3a), and peel off the muscles around the back. Then cut off the joint of genitalia, rectum and skin, clean up the connective tissue around the caudal base, hold the caudal base with your left hand, and slowly pull the caudal vertebra up with your right hand until it is completely pulled out (Figure 3-3b), and then peel it off to the forelimb, cut off the elbow joint, remove muscles and peel it off to the head. Use a scalpel to cling to the skull to the ear. When cutting or cutting the ear root to the eye, you can see a layer of white reticulate eyelid margin, and carefully cut it off. When peeling off the upper and lower lips, first cut off the cartilage at the tip of the nose, and then peel off the lower lip with a scalpel. At this point, the skin and the body have been separated, the fat in the skin and the muscles attached to the skin are removed, the antiseptic is evenly coated, a little cotton is wrapped around the bones of the limbs to replace the original muscles, and then the mouse skin is turned over to form a straight tube with the skin facing outwards.

Fill and cut the 1 bamboo pseudococcyx, which is slightly thinner and smoother than the original coccyx, or make a pseudotail by tightly winding cotton with lead wire, and insert it into the tail of rats. The pseudotail is longer than the original tail and reaches the abdominal cavity 1/2, so that the tail can be fixed and the whole body can be supported. Then, the fluffy cotton is kneaded into a shape that is thin at the front and thick at the back, the front end of the cotton is clamped with big tweezers, and then it is tightly inserted into the head from the opening, and then the fluffy cotton is properly filled in the insufficient parts of limbs and trunk. At this point, the cut coccyx should be close to the cotton in the abdomen, so that the coccyx does not become warped. When sewing the incision, the specimen should be put straight and the needle should be sewn from the inside out.

The quality of plastic surgery and fixed specimen making has a great relationship with plastic surgery. During plastic surgery, the specimen should be placed horizontally on the table, with the head facing left, the front legs retracted, the palm side down, the rear legs straight, the sole side up, and the tail flat, and cotton should be picked up with tweezers to look like a slightly convex eyeball. Hair should be neat, ears should be upright, head should be slightly pointed, and hips should be arched (Figure 3-4). The label is attached to the right foot, the specimen is placed on the fixing plate, and the limbs are fixed with pins. After drying in the shade, the fake peeled specimen was made.

(2) The ecological specimens of museums, teaching and other units often make animal specimens into life postures for popular science. The method of stripping is basically the same as that of pseudo-stripping specimens. When filling, only lead wire (steel bar or steel plate for large animals) is needed to support its limbs. The type of lead wire used depends on the size of the animal itself. The head, limbs and tail are supported by 1 wire respectively. The lead wire of the head is first rolled with cotton into the same thickness and length as the original muscle of the neck, and one end is fixed on the skull. You can also keep the original skull. In addition, the 1 lead was inserted into the limb from the sole of the foot along the posterior side of the limb bone, leaving a section for fixation. Lead wire is bent along the bones of the limbs and tied to the bones with thread. It is still necessary to add cotton to the limbs to replace the original muscles. The coccyx should not be made of bamboo, but must be made of lead wire in various postures.

(2) Specimen making of medium-sized mammals generally refers to rabbits, marmots, giant squirrels and weasels, such as weasels. The preparation method is basically the same as that of small mammals. Because this specimen is relatively large, the opening of the abdomen is slightly larger. When filling the body with bamboo filaments, a bamboo stick is needed to support the body.

(3) Specimen making of large mammals generally refers to tigers, leopards, wild boar, deer, etc. And there are generally two methods of making, ecological specimens and preserving skin and skull without filling prosthesis for scientific research. Taking this kind of specimen as an example, it can be made from the root of the tail to the snout and the inside of the limbs. However, when dealing with horned cloven-hoofed animals, it is necessary to open a "ya" mouth between the two horns and the back of the neck, and cut off the skin around the root of the horn; When the angle is large, it needs to be operated on the neck side. In addition, the hooves and claws of the limbs need to stay on the skin.

(4) Preparation of liquid immersion specimens of some small animals (such as bats and mice). ), this method can be used to prevent decay and alopecia, because the field work conditions can not be completed at one time, or because the purpose of classification can not be clearly seen after the specimen is dried, and because of the research needs of internal organs. The method is to soak the organs exposed from the abdominal opening with 75% alcohol solution or 5 ~ 10% formalin solution. Before soaking, each specimen should be tied with a numbered bamboo stick for easy reference.

(5) Preparation of bone specimens by insect erosion This method is suitable for preparing various bone specimens of vertebrates. Take animal specimens as an example. In the past, they were usually peeled and eviscerated first, then cooked with clear water, and then the muscles attached to bones were removed with tweezers. However, it was time-consuming and laborious, which easily damaged the specimens and affected their classification, identification and collection. In recent years, China has adopted the carnivorous habit of Coleoptera insect-dermatophyte larvae to remove muscles attached to bones, and achieved good results. Introduction is as follows.

① Morphology and insect source: The stinkbug's body we used is oval, black or reddish brown, or patterned, with a length of 2 ~12mm; Larvae has segmented body and long hair. House dust mites are distributed in the north and south of China. They not only like to eat meat, but also bite books, clothes, rawhide sheets, medicinal materials and so on. When this method is carried out, it is necessary to collect and cultivate insect groups first, and it is best to collect midges in warm spring and summer. At this time, you can attract them with flesh and blood, or you can collect them in slaughterhouses where midges often move, stalls selling flesh and blood, and fur warehouses of animal husbandry companies.

(2) Insect erosion culture method: put the collected midges into containers with smooth surroundings, such as rectangular iron boxes and large glass containers. The bottom of the container can be covered with a layer of cotton. If the container is large, a layer of big eye partition or barbed wire can be added within a certain distance. In order to make the air in the container circulate, it is not easy to climb out. There is a window at the top, which is covered with fine barbed wire. Peeling, cleaning, drying, air-drying and putting the dead bodies of wild animals or insects into a container. At this time, the temperature of the container should be kept at 27 ~ 29℃ and the humidity should not exceed 70%. In order to maintain a certain temperature and humidity, you can put a small dish filled with water in the container. If the temperature and humidity are moderate, the skulls of small mammals can be cleaned in just over ten hours, and sometimes it takes 2 ~ 3 days for medium animals. When this method is implemented, it should be checked at any time to avoid excessive moth-eaten and lead to bone loss. Completely dehydrated dry specimens should be soaked in water. This method should be carried out after the muscles are soft and dry. After insect erosion, bone specimens still retain the original color of bones. If it is not used for classification and identification, 4% hydrogen peroxide can be applied to the bone surface to obtain a white specimen.

③ Precautions: House dust mite is an important pest, so it should be prevented from escaping and causing harm. If there are too many insects or stop feeding, you can scald with boiling water or burn with fire.

(6) There are generally two methods to make bat specimens according to their uses.

① Liquid immersion specimens Bats are social animals, and sometimes they are caught at one time. Except for some specimens, the rest can be preserved in 70% alcohol solution. The method is to cut a gap in the abdomen of the bat, and the size of the gap is subject to the immersion of the solution into the viscera. Scientific research needs to record all kinds of measurement data before soaking in liquid, and then write down the specimen number on the bamboo pole with drawing ink or pencil, tie it to the left foot (the line should be short to avoid winding) and put it in a container. After the field work, it is necessary to identify people as soon as possible, and put people in a jar with 70% alcohol solution as a unit. The scientific name, place of origin and collection time still need to be indicated outside the bottle.

② Fake peeled specimens can be made into scientific research specimens by this method.

There are two kinds of skinning: back skinning and abdomen skinning. Because the thick back is not easy to destroy the classification of specimens and has obvious characteristics, it is better to peel the back. The specific operation method is as follows. Cut from the back 1 ~ 2 cm away from the tail end, cut along the back line to the waist, gently separate the meat with your hands, hold the hind limb with your hands, cut at the joint between the femur and the body, remove all muscles, and do the same for the other hind limb. * Bones can be cut off from the base. After excision of genitalia and rectum, clamp the caudal base with tweezers, pull out the caudal vertebra with your left hand, then turn over the skin, peel off the flesh from the chest, cut off the upper arm bone and scapula, pull out and scrape off the muscles; When dealing with the head, use a knife close to the skull to cut off the ear root, eye margin and upper and lower lips in turn. Finally, in order to prevent insects from eating in the skin, arsenic is evenly spread everywhere.

When filling, the hair is turned outwards, the upper end of humerus, forearm radius and hind limb are pulled back to their original positions, and the coccyx is replaced with peeled bamboo sticks or thin lead wires. Take a lump of cotton which is 1 times larger than the original volume, fold one end into a skull shape, clamp it with tweezers, push it up from the back opening to the kissing end, and then make up for the deficiency with extra cotton. At this time, the false coccyx should be placed on the upper part of cotton. Fill it out before sewing. There is no need to sew a kiss. Just pull down the upper lip and cover the lower lip. Straighten your hair and do preliminary plastic surgery with your abdomen facing up. During plastic surgery, the chest is slightly fuller than the original shape, the abdomen is naturally flat, and other parts are arranged according to the original shape.

The pterygoid membrane of fixed bat specimens is brittle and easy to fold after drying in the shade, so it must be sewn on hard paper, which is not only difficult to deform, but also will not be damaged after long-term use. The method is to take a piece of hard paper (horse manure paper is enough) which is larger than the one-sided spread-wing specimen, and sew the abdomen of the molded specimen up on the paper. It is customary to fold the right wing and extend the left wing, one by one (Figure 3-5). The external morphological features of bats are mostly concentrated in the head, so it is necessary to arrange the ears (including tragus) and nose wings after sewing, and carefully shape them in the process of drying in the shade, so that they can still maintain their original shapes after drying in the shade. Bat skulls are also essential for classification and identification, and can be sewn on paper with specimens.

Method of making insect specimens:

How to use insect needle (1)

Generally speaking, the needle of an insect penetrates into the center of the insect's chest. In order to ensure that the important taxonomic features are not destroyed, and to standardize the making of similar specimens, the needle-fork beetle should avoid the basilar fossa of the chest and foot in the chest and abdomen, and thread the needle in front of the right-wing sheath, so that the needle just passes between the middle foot and the hind foot in the right book. For Hemiptera insects such as salamanders, the needle should be slightly to the right of the small shield, which not only protects the integrity of the small shield, but also does not damage the beak and beak groove on the chest and abdomen surface. Orthoptera insects, such as locusts, should insert the insect needle behind the anterior thoracic backboard, with the dorsal midline to the right, so as not to destroy the integrity of the classification characteristics on the anterior thoracic backboard and webbed. Hymenoptera (bees and ants, etc. ) and scales

Chiroptera insects (butterflies, moths) are inserted from the center and pass through the middle of the midfoot basal ganglia.

The use method of short needle (double needle) is to insert the small triangular paper (or matchstick with a length of 1.8mm) made of hard white paper or transparent film into the long needle, then insert the No.00 short needle into the triangular paper or matchstick (the needle tip is upward), and finally insert the insect specimen into the short needle. This method is specially designed for making tiny insects.

There is also a way to make tiny insect specimens that don't need to spread their wings, that is, insert a special small triangular paper on the insect needle, then stick transparent glue on the tip and stick the right side of the insect body on it.

Method for making double-soaked insect specimens

Most specimens of soaked insects are preserved in Chiroptera, collembola, Diptera and Cypoda, as well as eggs, larvae, pupae of larvae and completely deformed insects such as Odonata and Mayflies that live in water. In order to prevent the insects from deforming after soaking, the larger insects should be scalded with boiling water first. Cooking time depends on the size, tenderness and species of worms. Generally, it can be cooked until the worm is straight and slightly hard. For large larvae with thick skin, it takes 5- 10 minutes to cook, and for small and soft larvae, 2-3 minutes is enough.

Uncooked larvae usually shrink and change their size and shape when immersed in preservation solution.

Even make the bugs black. Therefore, this step is essential when soaking necessary specimens such as insect larvae. If the conditions are limited, you can also take a hot bath with boiling water, similar to instant noodles.

Samples boiled in water or hot water bath are immediately put into preservation solution for preservation. However, larger insects or species with too much water in their bodies need to be replaced many times in a period of time before they can be preserved for a long time, otherwise the specimens will rot or be polluted because of too much water brought into the preservation solution.

3. Method of making exhibition samples

Insect specimens for exhibition are mainly used for popularizing insect knowledge, teaching and visiting. The production method is to arrange insect specimens in an exhibition box according to their life development order, such as eggs, larvae of different ages, pupae, adults and so on. At the same time, relevant information should also be put in the box: leaves of damaged plants, natural enemies, photos of prevention or utilization, etc. Through the exhibition of boxes of specimens, the audience can learn about the life of an insect and its relationship with the environment and natural enemies. When making adult specimens in the exhibition box, the species that need to spread their wings do not need to be fixed with insect needles. Instead, put the specimen face down, lay it flat on the posture table, and nail the chest with a real tip.

Spread your wings and straighten your posture. After drying, pull out the insect needle and stick it in the appropriate position of the exhibition box. Larvae, eggs and pupae can be made from inflated or soaked specimens, but they should be sealed. The method of making the soaked specimen is as follows: firstly, put the specimen in a glass bottle with good texture, put cotton or foamed plastic of various colors close to the specimen, so that the insect body can't roll in the glass bottle, then burn one end of the glass opening with an alcohol torch or an oxidation flame torch, pull it into a tiny fine mouth with tweezers, inject preservation solution with a syringe, and then burn the fine mouth to heal it. Fix it in place in the display box as needed.

You can also use the glass specimen method, which is similar to the exhibition box, but you don't need cotton, and you can use glass from top to bottom. Because of space problems, I won't introduce it. If necessary, please contact this site.

Method for embedding insect specimens in plexiglass

Insect specimens similar to artificial amber were made by embedding methyl methacrylate (common name plexiglass). Its advantages are no fear of moth, no enzyme production and no damage. Because of its transparency and easy observation, it is especially suitable for exhibitions and teaching materials.

Materials and tools:

The raw materials for making plexiglass embedding are raw and cooked monomers bought from chemical raw materials stores. (1) The raw material monomer is unpolymerized methyl methacrylate, which is colorless and transparent.

Bright liquid, used as a solvent when embedding specimens. (2) The mature monomer is polymerized methyl methacrylate, which is a colorless transparent viscous liquid. It can only maintain its original properties at a low temperature of 5 degrees Celsius, and it will polymerize and harden at a high temperature. Therefore, raw and cooked monomers should be stored in large glass stoppers and kept in the refrigerator. In order to facilitate the use and avoid improper disposal of waste materials, some monomers can be poured into two small 50 ml wide-mouth bottles for use.

Preparing insect specimens for embedding:

It is best to choose the adults of COLEOPTERA, ORTHOPTERA, Hemiptera, HYMENOPTERA and LEPIDOPTERA with complete limbs, bright colors and hard skin. Viscera of larger insects and larvae of various insects can also be used for embedding, but the required procedure is complicated due to the high water content. No matter what kind of insects are embedded, it is necessary to comb and clean in advance to improve the clarity and aesthetics.

Molding:

The utensils are glass plate (bottom) and glass slide (edge). The manufacture of the mold depends on the external shape of plexiglass embedded in the specimen: square, rectangle and diamond (if it is made into a circle, flat glass dishes with different sizes and good quality can also be used as the mold). After the mold shape is determined, the required glass mold should be scrubbed and checked repeatedly. If the surface has scars or fuzz, it can't be used, so as to avoid difficulty in demoulding or uneven surface of specimen buried block. When making a mold, first put a square piece of paper under the glass plate, so as to enclose a satisfactory shape with a glass slide. Then dip a little boiled monomer on the seam of the glass slide with tweezers to make it flow down the outside of the seam to bond the seam. This bonding method needs to be carried out twice. Then put it in an incubator at 40 degrees Celsius for about half an hour to make the mature monomer polymerize and harden.

After the mold is completed, 4-5 mm of cooked monomer can be injected (not too thick to prevent the adhesive part at the joint from dissolving, and if there are bubbles, puncture them with a scalpel). Put it in a warm fragrance at 40 degrees Celsius for 12 hours to polymerize and harden it into a fixed layer. In case of multiple injections, the thickness of hardened monomer should be not less than 3mm. In order to mark the name of the embedded insect, before the second injection of the cooked monomer, the label soaked in the raw monomer and clearly written with drawing ink is put into and dissolved in the cooked monomer. The posture to be placed depends on the situation.

Embedding:

Firstly, the dried insect specimen is soaked in the raw material monomer for about one hour, so that the insect body is completely soaked. At this time, the mature monomer is injected into the pre-made mold, but this time the amount should not exceed half of the thickness of the worm, so as to avoid the worm drifting position after placing the specimen. Then take out the specimen from the raw monomer, make the back of the worm face down, and put it on the cooked monomer in the mold. Adjust the position of the specimen with tweezers or dissecting needle. When it is stable, move it to a box with a glass cover to avoid dust for future observation. Although this polymerization takes a long time, it is not easy to produce bubbles. Two days later, probe with a scalpel. When the cooked monomer has been polymerized into semi-solid and not completely hardened, 5 mm of cooked monomer can be added. After that, every 1-2 days, before adding the cooked monomer, check as above. But in the future, it is best to inject from one end of the mold to avoid irregular injection squeezing each other to produce gas that is not easy to exhaust.

Molding and shaping:

After demoulding, it can be trimmed with scissors, steel hammer and grindstone, especially the final polymerized part. After completion, some parts will lose luster and can be polished with a cloth polisher.

The label on the insect specimen is the most original record on the specimen, which is equivalent to a one-page household registration book. The prepared specimens should be labeled in time. ================

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For the newly prepared specimen, two labels should be inserted immediately (with a black box with a length of 1.5cm and a width of 1.0cm): the first label indicates the collection place, altitude and collection time; Write down the name of the host or collection method, environment and collector on the next page. After research, the insect specimens with scientific name and Chinese name after systematic research were checked, and a third label with Chinese name, scientific name and appraiser name was added below. After research, the new species that have not been discovered by predecessors should be marked as new species or subspecies under the specimen.

The label of new species uses three different colors to represent the grade, and the most typical one is selected from the specimens of new species, designated as the normal specimen, and the red label is used below; Choose a matching specimen that is exactly the same as the normal specimen but different in sex, and use blue label; The rest, as a secondary mold, should be labeled yellow.

Labels should be clearly written in drawing ink to prevent fading or blurring over time. Be more careful if you soak in a specimen bottle.