Sea urchins are marine creatures, and although they look like plants, in fact they are echinoderms. They are round in shape, with long thorns on them, and some sea urchins are shaped like hearts. They are all black in color. Of course, different species have different colors, but black sea urchins are more common. The shell of sea urchin is strong, but after opening the shell, the inside is very delicious food.

They are close relatives with starfish and sea cucumbers, and they all belong to invertebrates. There are many kinds of sea urchins, including more than 20 orders and more than 900 varieties, and more than 7,000 fossil species have been found so far. They are distributed all over the world and have a wide range. Sea urchins are omnivores, which often eat algae, worms and other foods, and can play an important role in marine ecosystems.

Sea urchins are poisonous, but not all sea urchins are poisonous. Because there are many kinds of sea urchins, most of them are poisonous, and only a small number of sea urchins are non-poisonous.

In addition, different sea urchin toxins are different. Some sea urchin toxins can affect human respiratory system, which may lead to respiratory failure and dyspnea. There are also some sea urchin toxins that have paralyzing effects, and they will paralyze people's muscles. There are also some sea urchin toxins that directly harm the human heart, and some will directly cause people's heart to stop working.