3 spot crab is a specific type of crab that is prized for its meat and its shell side. The most common coloration of the three-spot crab’s carapace is red, so they are often referred to as “red crabs”. However, some three-spot crabs tend to be yellow or brown.
This beauty has a wide range of sizes and kinds that can be found in different types of water. This one looks quite common, but the two spots on its back are distinctly different.
The “three spots” is a red oval shape with a thin black border between three white dots…the spots are completely visible on this gray crab. Spot crab, also known as the redbreast crab, is called such because it has three white spots that can only be seen when it’s in motion or swimming through attacking predators.
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How to identify 3 spot crabs?
3 spot crabs are the small crab species of coral reef. They are the smallest in size but can be gathered in massive amounts. Three spot crabs live in the Indo-Pacific region, their average size is about 2 cm (0.78 in). They show a wide variety of color combinations: beige, yellow, orange, and black with red spots on their shell [mostly].

Their body is smooth and soft with their legs having two claws each; however, males have bigger claws than females. The three-spot crab lives in the shallow waters (about 2–8 m deep) of coral reefs, where it hunts small sea creatures as its food source.
Their diet consists of various types of worms, sea urchins, crustaceans, and algae. Even though they are soft-shelled crabs, they are very aggressive and agile swimmers. They swim at a high speed with their two front claws punching water at a great speed; they do this to catch their prey and escape from predators.
Where are they found?
As mentioned above, three spot crabs inhabit the Indo-Pacific region. They are found in the West Pacific and the Indian Ocean, from the Red Sea to Polynesia. Three spot crabs are also popular in aquaculture because of their delicious meat and their use as bait for other aquatic animals. 3spots live in the coral reef region, they can be found most of the time on corals and rocks. Their life is often threatened by human activities…

Origin of three spot crab?
Since they are an important food source, it’s no big surprise that three spot crabs have been farmed for over 100 years. They were introduced to Chinese culture during the Qing dynasty. They were also introduced to Japan, South Korea, Taiwan, and other Asian countries.
From there the species spread to Taiwan in 1920, and it started being farmed in South Korea somewhere between 1950 and 1960. It was then introduced in Polynesia around 1968-1969 by Japanese fishermen who used them as baits.
Good effect on humans?
Many use these little crabs as food. Some eat their meat, some the soft shell, and some both. Three spot crab is very popular in many Asian countries like Japan, China, and Taiwan. In China, three spot crab is considered a delicacy that can be served raw or cooked. It is often used as a topping for soups or mixed with other ingredients for traditional medicine.
Its shell serves as a good ingredient for medicine or decoration of the ceremony room in Chinese culture. The tooth of the three-spot crab is also prized and people often use the shells as decorations. 3spots in aquaculture can be farmed in the following states: Australia, China, Indonesia, Japan, Korea, and Taiwan.
Bad effect on humans?
3 spot crab is also used as bait by various fishermen and fishermen. They are generally caught in traps known as “pots”; these are used to catch fish that would be hard to catch with nets. The method of catching the fish varies, but most involve eating the three spot crab only for them to be damaged or even die shortly after.
10 important information about Three spot crab
Found | The Indo-Pacific region, in the West Pacific, and the Indian Ocean. |
Size | They have a body size of about 2 cm (0.78 in). |
Food source | For their food source, they are omnivorous and consume small sea creatures such as worms, sea urchins, crustaceans, and algae; their favorite food is small crabs and sea urchins. |
Color | 3 spot crab shows a wide variety of color combinations: beige, yellow, orange, and black with red spots on their shell. |
Habitat | They live in coral reef regions, they can be found most of the time on corals and rocks. |
Impact of human activities | 3 spot crab is also used as bait by various fishermen and fishermen. They are generally caught in traps known as “pots”; these are used to catch fish that would be hard to catch with nets. |
Fertility | 3 spot crab lays their eggs in the summer, the eggs are laid in a pair and each has a size of about 1.4 to 2.3 mm in diameter. |
Life expectancy | 3 spot crab live for about 4 to 5 years, but can live longer than that; this information is based on the rate at which they grow and age. |
Claws | They have a pair of claws on each leg. |
Anatomy | The body of the three spot crab is smooth and soft with its legs having two claws each. The males have bigger claws than females. |
In summary
Three spot crab is a small crab species of coral reef. They are the smallest in size but can be gathered in massive amounts. Three spot crabs live in the Indo-Pacific region, their average size is about 2 cm (0.78 in).
They show a wide variety of color combinations: beige, yellow, orange, and black with red spots on their shell [mostly]. Their body is smooth and soft with their legs having two claws each; however, males have bigger claws than females.