First of all, the threaded conch, commonly known as the sea screw, is produced in Zhejiang, Fujian, Guangdong coast. The appearance of the snail is characterized by a pointed tail, long and thin, about 1 cm in length and 0.5 cm in width, about the size of a fingernail.

The snail itself is non-toxic, and its fatal toxicity is poisoned after ingesting toxic algae in red tide. The main toxin that causes food poisoning in threaded snails is paralytic shellfish toxin, similar to tetrodotoxin.? Due to the large amount of industrial wastewater and domestic sewage, etc. discharged into the sea, resulting in seawater eutrophication, the South China Sea, the East China Sea, the Bohai Sea and the Yellow Sea are frequent red tides in different seasons. Some of the algae in the red tide can produce toxins, and the snails are enriched with toxins due to ingestion of toxic algae or other toxic substances (such as tetrodotoxin, etc.). Poisoned patients mainly become neurological paralysis symptoms, the mortality rate is high.

Then Shandong people often eat the sea melon seeds, also known as sea screws, the scientific name of the blunt crab snail, a kind of conch family. Shell is tower-shaped, about 2 cm long, shell slightly thin solid, screw layer is usually 8 layers, the shell surface is yellowish white, shell bottom white, shell mouth ovoid, the inner surface has a fine groove, more inhabited in the intertidal zone in the upper tidal zone, ebbing tide in the intertidal zone mudflat or mud sandy beach crawling life, or hidden in the rocks next to the tide, the average perching density of 4 / square meters, distributed along the coast of the Yellow Sea, for the river estuary near the salty and fresh water! The most common species. Fishermen are often caught at low tide.

The obtuse crab snail has a very sharp end like a cone, so people call him the sea cone. Qingdao people call it sea melon seeds, usually it boiled in water, come to the guests to take out, just like the city people eat melon seeds, the meat is very delicious, usually with a big pin to pick food; can't eat, the sea melon seeds tail don't break off, with the mouth sucking to eat. The snail meat is only the size of a dime, but its fresh, tender taste, I'm afraid no other thing can replace.

Sea squash seeds and sea snails in appearance is almost the same, it is difficult to see the difference between the two, but from the color is still a little difference, the color of the sea squash seeds yellow, and sea snails gray-black, in the purchase of the time you can distinguish between sea squash seeds and sea snails according to the color.