Biology teaching specimens play an important role in middle school biology teaching with their vivid and intuitive characteristics. There are many kinds of marine life. As far as invertebrates are concerned, different animal species have different specimen making and processing methods. This paper introduces several common and representative methods of making and processing marine animal specimens.

First of all, jellyfish

After collecting the whole jellyfish, put them in a container filled with fresh seawater and let them stand. After returning to the natural state, anesthetize with 1% magnesium sulfate solution for about 20 minutes. When animals stop moving, they are killed with 7% formalin solution and then moved into 5% formalin solution for preservation.

Second, anemones

Anemones like to live a settled life. When collecting, it is best to knock down the stones together and put them in a container filled with seawater. When the tentacles of anemones are fully extended, they should be anesthetized slowly with menthol (menthol is wrapped in gauze to the size of soybeans). After 3-5 hours, when their bodies are no longer shrinking, they should be gently stroked, that is, 40% MgSO4 _ 4 saturated solution should be sprayed on anemones several times, and then 5%-7% should be used after 20-30 minutes.

Third, shellfish.

Shellfish is a kind of animals with calcareous shells in mollusks. Different shellfish have different sizes, shapes, stripes and colors. Therefore, shellfish morphology is one of the most common and important taxonomic bases in shellfish taxonomy. When making shellfish specimens, there are dry specimens and soaked specimens.

1, make a dry specimen.

There are two methods to make dried shellfish specimens: boiling and sand burying.

Sand burial method: take out the visceral mass and take its calcareous shell as a specimen for preservation. Bury the collected shellfish in the sand, take them out after complete decay, wash away the dirt with clear water, and dry them for preservation.

Cooking method: Some shellfish are seafood and have high edible value. For example, to make a dry specimen, you should first cook it with water, eat the fleshy part, and then wash the shell.

2. Preparation of soaking samples

Put the collected shellfish samples into a container filled with seawater, fully stretch them, anesthetize them with MgSO4 _ 4 _ 4 for 3 hours, pour out the seawater, kill them with 10% formalin solution, and move them into 5% formalin solution for preservation after 8 hours.

Fourth, crabs.

Put the collected crabs into a large glass bottle, dip a little chloroform or ether with absorbent cotton, tightly plug the bottle cap, anesthetize for half an hour, and store in 10% formalin fixed solution. Don't throw it directly into the fixed liquid, otherwise it will break the limb.