Preparatory work/about to start work
A) using tools
Scalpel: used to dissect organs, nerves and blood vessels.
Scissors: used to dissect and cut off redundant tissues, make nerve specimens and cut off bones. It is best to use wide-headed scissors to cut nails for civil use.
Tweezers: used to hold materials.
Anatomical plate (wax plate): used for fixing materials.
20 ml syringe: used for injecting preservatives.
Specimen bottle or jar: used to hold soaked specimens.
Pin: used for sample setting.
Glass sheet: inserted into the sample bottle to fix the sample.
Plastic film, gauze and wax thread: used to seal specimen bottles.
B) chemical supply
40% formaldehyde solution (formalin) or 95% alcohol: used as preservative.
Ether: Used to anesthetize animals.
Polyurethane (Maritain) glue: used to seal specimen bottles.
Paraffin wax: preparation of sealing wax for specimen bottles.
Synthetic camphor: used as an insect repellent.
Naphthalene: Used as an insect repellent.
Preparation of vertebrate specimens
A) When the whole preserved animal specimens are soaked, the preservation solution is not easy to penetrate, and the internal organs are easy to rot after a long time, so the preservation solution should be injected for preservation. You can insert a needle on the syringe into the head, chest and abdomen of the lizard and inject a small amount of 10% formalin respectively.
B) The fixation of plastic-impregnated specimens is very important, which should be done carefully from beginning to end. Anatomical plate or wax plate when fixed. Put the lizard injected with preservative flat on the anatomical plate, with its back facing up, and put a wadding pad under its head and neck to raise its head. If you want to open your mouth, you can put a filler in it. Arrange forelimbs, hind limbs, trunk and tail according to ecology, and fix fingers, toes and tail with pins (see Figure 8). If the specimen bottle is short, you can bend the tail. Grass lizard's tail breaks easily. If the tail is broken, you can insert it with thin bamboo wires, connect the broken tail, and then straighten your posture. Soak the brush in 40% formalin and apply it to lizard skin twice. After 1 hour, the fingers, toes and tail tips of the front and rear limbs of the lizard specimen have been set and hardened, and the needles are taken out and soaked in 10% formalin. 10% formalin can be used as a transitional immersion liquid, which can soak the yellow liquid in the lizard body and avoid polluting the immersion liquid when it is formally bottled. Samples should be soaked in 1 ~ 3 months, and new liquid should be changed 3 ~ 4 times in the middle until the immersion liquid no longer turns yellow.
Figure 8
A) bottling: taking the lizard out of the 10% immersion liquid, threading white silk thread with a needle, threading white silk thread on the front limb of the lizard's chest and the rear limb of its abdomen, tying the silk thread on the glass sheet, tying the white silk thread at the edge of the glass sheet, or tying the whole specimen on the glass sheet, then making the cushion angle of the glass sheet, mounting it on the glass sheet, and then loading it into the cleaned glass sheet. Put the specimen in the bottle, then add the preservation solution and cover the bottle cap. The storage liquid in the bottle should not be too full, and the liquid level should not touch the bottle cap. Take resin glue or wax, dip it into the gap between the bottle cap and the bottle body with a brush until it is filled, and then stick a label on the bottle body.
protect
Don't put the soaked specimen in direct sunlight to prevent the sealing wax at the bottle mouth from melting and the immersion liquid from volatilizing. It should not be stored below zero to prevent the immersion liquid from freezing and the glass from breaking. When moving, don't shake violently, but lay flat to avoid tipping over.
1.4. 1.3 peeled specimens: instruct students to learn how to make peeled specimens, and understand the knowledge of recording appearance, execution, peeling, anticorrosion, installation, fixation and shaping. The preparation of animal skin specimens refers to vertebrates, that is to say, most species of vertebrates can be made into skin specimens, but in practical application, it is mainly suitable for mammals and birds, as well as other large species of various classes that are not suitable for soaking, such as whales, sharks, turtles and so on.
There are many kinds of animals, and their external shapes, body sizes, skin conditions and so on are very different. In the production process, we must adopt different methods according to different situations. For example, birds are usually skinned from the abdomen, but cormorants can be cut from the back because of the fat in the abdomen and the feathers at the opening of the abdomen are easy to pollute. In addition, the process of making specimens varies from person to person, and there are many ways to make specimens. For example, when making bird specimens, there is a difference between cutting from the chest and cutting from the abdomen. As long as the specimen is vivid, ecological and realistic, it is a good work.
Commonly used drugs
Arsenic trioxide (As2O3), also known as arsenic, is a white odorless and tasteless powder, which is highly toxic and has antiseptic effect.
Potassium aluminum sulfate [K2SO4 Al 2 (SO4) 3 24h2o], also known as alum, is colorless and transparent, and has the functions of anticorrosion and scale prevention.
Camphor (C 10H 16O) has the function of preventing insect column specimens.
Boric acid (H3BO3) has antiseptic effect, but it is poor.
Phenol (C6H5OH) is also called carbolic acid and lysol. It has the functions of disinfection and antisepsis, and can prevent residual muscles from deteriorating.
Preparation of preservative
Arsenic disinfection powder: mainly used for reptiles and mammals. When preparing, the arsenic, alum and camphor are ground into powder according to the ratio of 2: 7: 1 and mixed evenly.
Boric acid disinfection powder: it can replace arsenic disinfection powder, but it is worse than arsenic disinfection powder, but it is safer to use. Just mix boric acid powder, alum powder and camphor powder in a ratio of 5: 3: 2.
Arsenic antiseptic cream: It has the functions of antisepsis, insect prevention and feather protection. Mainly used for birds.
Common tools and materials
Anatomical tools: such as scalpels, tweezers, scissors, bone scissors, etc. Can be prepared according to economic conditions.
Woodworking and metalworking tools: such as wire cutters and vises. ? Head, electric drill and saw can be prepared according to conditions.
Gypsum powder (or talcum powder): It has the function of absorbing water, and is mainly used to absorb the water of washed bird feathers. When peeling, it is scattered between muscles and skin to prevent adhesion and prevent blood and fat from polluting feathers.
Lead wire: used for supporting animal specimens. Models with different thicknesses can be selected according to the size of animals.
Filler: mainly used for filling specimens, with cotton, bamboo silk, hemp knife and brown to choose from.
Glass artificial eye: It can be used to replace the eyes of animals.
Needle and thread: used to suture incision specimens.
Specimen table, branches, etc. : Used for fixing animal specimens.
Mark and record the name, sex and collection place of animal specimens.
Execution of birds and mammals
Living animals generally need to be slaughtered 1 ~ 2 hours before skinning, and can only be skinned after blood coagulation. There are several execution methods, which can be selected according to different animals.
Chest compression. Make it unable to breathe, heartbeat and die.
Air acupuncture. Inject a small amount of air intravenously into animals to block blood circulation, such as rabbits can inject it from the ear; Birds can be injected from the medial arm vein of their wings.
Drowning Can be used for mammals.