There are parasites.

The parasites on razor clams are usually a kind of organism called "razor clam-eating intestinal trematode", which is yellowish-white, milky-white, and about 2 centimeters in length, and completely different from the crystal rod. Parasitized razor clams are too thin to continue reproducing, and more than one living organism will crawl out of their abdomen when squeezed. People who eat cooked razor clams containing parasites are generally fine, but those with poor gastrointestinal function may have indigestion and other reactions.

Parasite characteristics

From natural life to parasitic life, parasites undergo a long process of adaptation to the host environment. Parasites have long been adapted to the parasitic environment, to varying degrees lost the ability to live independently, for the nutrition and space dependence of the parasite, the greater the dependence on the parasite, the weaker its ability to live on its own; the longer the history of parasitic life, the more the ability to adapt to the more acid, the greater the dependence, the parasite can only selectively parasitize a certain kind of host or a certain kind of host. This selectivity of the parasite to the host is called host specificity (host specificity), which actually reflects the enhanced adaptability of the parasite to the internal environment in which it is parasitized.

Parasites can undergo morphological changes due to the influence of the host environment. For example, the flea's body is flattened on the left and right sides so that it can walk between the fur; the worms parasitized in the intestinal tract are mostly long, in order to adapt to the narrow and long intestinal lumen. Certain organs have degenerated or disappeared, such as the long history of parasitic intestinal tapeworm, relying on its body wall to absorb nutrients, its digestive organs have degenerated. Some organs are developed, such as the body of parasitic nematodes, the reproductive organs are extremely developed, almost all of the original body cavity, such as the female roundworm ovaries and uterus length for the body length of 15 to 20 times, in order to enhance the ability to spawn; some blood-sucking arthropods, the length of its alimentary canal increased greatly, in order to facilitate a large number of blood-sucking, such as the soft ticks full of once sucked the blood can be starved for a few years. The creation of new organs, such as trematodes and tapeworms, due to the need for settlement and attachment, the evolution of the sucker as a solid organ.

Intestinal parasites of roundworms, the body wall and protozoal luminal fluid, the presence of trypsin and chymotrypsin inhibitors, in the body of the worm corneal skin of these enzyme inhibitors, to protect the body from the action of proteolytic enzymes in the small intestine of the host. Many parasites of the digestive tract are able to obtain energy by enzymolysis in a low-oxygen environment. Female roundworms lay about 240,000 eggs per day; beef tapeworms lay about 720,000 eggs per day; Schistosoma japonicum hatch out of each egg and enter the snail, and the asexual proliferation of larvae can produce tens of thousands of caecal larvae, and single-celled protozoa proliferate to a much greater extent, suggesting that the parasites have increased ability to reproduce, and that it is a way of maintaining the survival of the worm species, and a manifestation of the adaptability to natural selection.