Crabs, with their progenitors dating back over 400 million years, are one of the oldest existing species. Before the dinosaurs, crabs existed for around 200 million years! There are almost 850 distinct species of crabs in the world, with approximately 4,500 different varieties.
You’ve come to the right place if you want to learn more about why crabs have been able to live for so long.
Classification & Species
Decapods are crustaceans with five pairs of legs on the upper half of their body. All crabs are categorized as decapods. At least one of these appendages will be transformed into a pair of pincers or claws. They have a carapace that covers their head and thorax, which are fused together.
Taxonomy of Crabs
The categorization of all living creatures on Earth is the responsibility of taxonomy, which is a branch of science. Based on what they have in common, all living creatures will be divided into groups. The higher down we go, the more particular their taxonomic names will become. There are various degrees of categorization.
The taxonomy of crabs is as follows.
Kingdom: Animalia — All multicellular animals are included in this group.
Phylum: Arthropoda — Insects, spiders, and crustaceans are all invertebrates (with segmented bodies, external skeletons, and jointed limbs).
Subphylum: Crustacea — Four or more pairs of limbs are modified into pincers by aquatic arthropods.
Class: Malacostraca — Compound eyes, which are usually stalked, are found in crustaceans.
Order: Decapoda — A carapace protects the head and thorax, which are merged.
Suborder: Pleocyemata — The female keeps fertilized eggs on the swimming legs (pleopods) until they hatch, which she does while they are incubated.
Infraorder: Brachyura — The animals’ bodies have short anabas that fold under it.
Crabs have been classified into four main categories for classification, in addition to taxonomic status.
The final pair of legs is used to classify crabs in this group. With a pair of hinged pincers, the thoracic legs are modified and closer to their back. These modified pincers are used to collect shells for their carapace, as well as to exhibit and eat with.
There are 300 extinct crabs and 240 current crabs in this collection. This group of crabs’ oldest fossil, found in the Jurassic period, some 200 million years ago, dates back to the Jurassic.
The abdomen of this crab superfamily stands out from those of other crabs. There are 182 species, four genera, and four families represented.
These crabs have been around for roughly 145–166 million years and are thought to have originated during the Cretaceous.
These crabs must use drag-powered swimming, a kind of swimming in which the crab paddles in a horizontal, circular motion, to travel around. Similar to how you row a boat, they push water behind them.
The Cyclodorippoidea family is a single superfamily found in this group of crabs. Cyclodorippidae, Cymonomidae, and Phyl lotymolinidae are three families that belong to this superfamily.
Heterotremata and Thoracotremata are two categories of crabs that are more physically and intellectually developed than other crabs. To differentiate between these two groups, the positions of the genital openings are used.
Males have legs with genital openings, whereas females have a sternum with genital openings in Heterotremata.
The sternum has openings for both male and female Thoracotremata.
Crabs from this group date back to the Bathonian period, about 168-166 million years ago.
Crabs are more vulnerable to predators when they mate after molting. A crab’s hard outer shell is shed when it molts, and a new softer shell develops underneath.
Because their hard exoskeleton makes mating difficult, they choose to mate after molting.
Males cradle a female who is about to molt before she does. The male will remain with the female after mating until she has regenerated her exoskeleton to keep her safe.
The female keeps its eggs beneath its belly after mating. Underneath their carapace, this is frequently seen as an orange spongey substance.
The basic life cycle of crabs is the same. While specifics vary between species, they all emerge and grow in the same way.
A crab’s basic life cycle is as follows:
- Juvenile Crab
- Adult Crab
Life Cycle of a Blue Crab
We’ll take a closer look at the life cycle of a blue crab in order to go into more detail.
The Zoeal Stage
Blue crabs don’t look like crabs when they first emerge from their eggs. They’re called zoea, which is a microscopic larvae.
In regions with a high salinity, young crabs will be floating throughout the water column. Microalgae, as well as smaller larvae, are eaten by them.
During its larval development, the blue crab will go through seven stages. Before becoming an adult crab, the larva will spend 31-49 days through these stages of larval development. The larva will seem to be very similar at each stage, yet they will grow somewhat larger.
Crab zoea have exoskeletons and must molt to allow their bodies to adapt, much like their adult counterparts.
The Megalopal Stage
The juvenile crab will go through the megalopal stage, in which the larva begins to assume a more crab-like shape, once the larval one is completed. It may take anywhere from 6 to 20 days to complete this phase.
The body of a juvenile crab grows larger as legs protrude from the sides, becoming wider. Their long abdomen, which stretches out behind their bodies, is still present from their zoea stage.
The megalopas prefer low salinity environments and many places to hide, unlike the zoea, who is free-floating. They’ll travel to estuaries, where it’s easier for them to find food, using the tides coming in and out.
The Adult Form
The crab will molt into its adult form, which is around 2 mm (0.2 cm) long, once it enters the estuary.
A blue crab remains in the estuary as an adult. During the summer months, they’ll molt more often, but when it’s cold, they’ll slow down. Ultimately, the crab will reach sexual maturity and go through a “terminal” molt, the final molt of their life cycle. They will no longer grow once they have molted for the final time.
When crabs mate, this is the terminal molt. The male will stay in the estuary for the rest of his life after mating, while the female will go to a location with greater salinity to prepare the eggs.
Female blue crabs store sperm for up to a year and are very picky about where they lay their eggs. By doing this, they may allow themselves sufficient time to locate the ideal position before extruding their eggs. They can also breed throughout the winter and wait until the summer to extrude their eggs, which means that they may do so.
As the eggs exit the crab’s body and move towards the “apron” beneath it, fertilization takes place. The abdomen is curled-under to enable the deposition of eggs, which is referred to as the “apron.” Little appendages that the eggs stick to may be seen there.
Millions of eggs, up to 8 million in a clutch, may be found in an egg mass. Because of the enormous quantities of yolks in the eggs at first, the egg mass looks orange. The egg mass will darken as the eggs develop and the larvae consume the yolks. In 1-2 weeks, the eggs will hatch.
The crab’s life cycle then continues, with just 0.0001% of the eggs making it to maturity.
The diets of crabs vary depending on where they live and the kind of crab.
Most crabs are omnivorous, meaning they eat both plant and animal material in general. They’re mostly scavengers, so if they can get their claws on anything, they’ll devour it. The diets of most crabs include the following foods:
- Decomposing plant debris or dead fish are examples of detritus.
- Live plants
- Other crabs
Crab protection involves a hard shell that protects their bodies from predators, but they are still vulnerable. Bass, halibut, cod, and sharks are among the larger, more aggressive fish that will readily consume a crab.
Invertebrates, such as octopi, devour crab in addition to fish. To rip open crab shells, they have hard, sharp beaks. A bite by an octopus kills a crab, and it paralyses the crab before it can retaliate.
Since they have enormous, strong jaws that can easily shatter crab shells, sea turtles are also a dangerous eater.
Crabs are also concerned about creatures like sea otters and seals, who may devour a considerable amount of crab in a single day. They are likewise concerned about ocean creatures feasting on them.
Additionally, crabs must be concerned about predators! When it comes to their smaller cousins, many larger crabs will go after them. Yet, like the blue crab, many crabs of similar size and species are cannibalistic and will attack each other.
Larval crabs, especially small fish, rays, and eels, are particularly vulnerable to predation in their early stages.
Habitat, Migration, & Range
Crabs come in a variety of shapes and sizes across the globe. Some species prefer cold water, while others prefer warm water, and they can be found in freshwater, saltwater, and brackish water. Even crabs may be found on land.
Blue Crab Habitation
Blue crabs have been the subject of most crab migration studies. They may be found down the US Atlantic coast, through Nova Scotia and Argentina, in northern New England.
Male blue crabs, such as estuaries and tributaries, prefer less salty waters. Females are more often discovered in the water or closer to it, and prefer salinity levels greater than those found in males.
Blue crabs prefer to hide in underwater grasses and oyster reefs in these areas of the ocean. Warmer, shallow waters are more appealing to them. The crabs will burrow into the murky silt that they dwell in when the temperatures drop too much for their liking.
While climatic shifts may cause crabs to hibernate, they will travel for various reasons, generally related to mating and reproduction. When a female blue crab is ready to lay her eggs, she will migrate to saltier waters, as we discussed in the previous sections.
Red Crab Migration
The crimson crab, for instance, lives on Christmas Island’s forests. They will move from the woods to the ocean when they are ready to reproduce. Thousands of crabs will be seen moving across roadways, streams, and beaches during this time.
Impact of Climate Change
Crabs are no exception to the effects of climate change, which are affecting every living species on Earth. The warming of ocean temperatures has had a big impact on the populations of crabs in the Pacific Ocean, according to Stanford University’s Hopkins Marine Station director and professor George Somero.
Students surveyed and identified every marine invertebrate in a 95-square-yard (79-square-meter) region of the Pacific Grove marine lab in the 1930s using a survey.
This research was rerun in 1993, and it was discovered that just 60 years previously, the northern species had vanished dramatically. Instead, they discovered that the number of southern species has grown by 8 out of 9.
As a result of the continued warming of ocean waters, we may anticipate that already northern-living crabs will migrate farther north in search of colder water as climate change continues to impact them.
Species that are accustomed to cooler waters will reach their “thermal tolerance” when they are placed in warmer waters. The animal may start to experience heart and nervous system issues, which might be fatal, as a result of thermal stress pushing the body over the edge.
The earth could climb another 6 degrees Fahrenheit over the next 50 years if ocean temperatures continue to rise at the current pace, putting northern crab populations in greater jeopardy.
Intertidal vs Subtidal
Between intertidal and subtidal habitats, Somero and his researchers conducted experiments to determine heat tolerance levels. Crabs that live in the intertidal zone are significantly more vulnerable to the effects of global warming than crabs that live in the subtidal zone, they discovered.
Since they may not survive if ocean waters rise, intertidal-living crabs on the Pacific coast are already at severe risk of breaching their thermal limits.
Cultural Symbolism of Crabs
In numerous cultures, particularly indigenous ones, crabs are often regarded as having symbolic and emotional power. They’re considered as a sign of life renewal or regeneration.
Their tribal belief that crabs never die, instead burying themselves to regrow their shells, is what connects them to the moon and gives them the astrological sign of “cancer.”
From 25 to 280 feet (8 to 85 meters) long, fishing boats will be found. The pots or traps are attached to a floating buoy and dropped into the water.
Trapping may be utilized up to a thousand feet (305 meters) in extremely shallow waters. Wire squares laid out in a grid pattern are commonly used as traps. The crabs are lured inside the traps by baiting them. The fisherman will return after a day or two and use a hydraulic block to lift the trap.
Types of Crabs
Most Commonly Eaten Crabs
Although there are many arguments about which crab species are the most palatable, the majority of eateries seem to agree on these five. These crabs are also the most widely distributed and plentiful species of crab across the globe, which is also logical given that they are the most common to eat.
1. Blue Crab
The Latin name for blue Crabs is Calinectes sapidus. They are referred to as “lovely swimmers.” Their “fins,” which function like a paddle to travel, may be used to swim through the water column. These are really a pair of flat back legs with “fins.”
They are gorgeous to behold in the wild, not just because they taste good. Their legs are a dark blue, and their shell is a light turquoise color. Their color changes when they are still alive, and as a result of their shells turning crimson once they have been prepared, their name comes from the hue of their bodies.
They are one of the most common crabs to eat, and being the most common crab species on the east coast of the United States, it’s no surprise. They may be found in the Atlantic Coast’s seas, from the Gulf of Mexico to the coast. Argentina has a few locations where they may be found.
2. Dungeness Crab
The Dungeness Crab has a wider habitation range than the blue crab. From Alaska to Baja, Mexico, they may be found in Pacific coastal waters. Dungeness in Washington State is the name of the first town to harvest them for food.
They live and are caught along this coast, however 70% of their total catch is captured between California, Oregon, and Washington.
These crabs must be at least 6.25 inches (1.60 meters) long and male, although they may reach lengths of up to 10 inches (0.3 meters). Dark brown to purple is the range of color in their shells.
These crabs aren’t particularly easy to get to the table, despite their popularity among restaurant customers. They’re great at slipping past guards undetected, and masters at disguising themselves and avoiding pits.
3. Snow Crab
Many names are given to the snow crab, the most accurate of which is Cancer quanbumi.
The rock crab, which is one of their most popular names, comes from the depths of the ocean, where they prefer to dwell. They may be found in US coastal waters along the east coast.
Because of their long, spindly legs that resemble the body of a spider, they are also known as the spider crab. It’s also known as the “queen crab” because of its lengthy legs. They have very lengthy legs, although they aren’t as long as the king crab’s.
Snow crabs are a costly crab that is one of the most common to cook with. The coasts of Alaska, Japan, and Canada, as well as Maine, are the only places where they are harvested.
4. King Crab
The spectacularly huge dimensions of king crabs are what give them their name. The king crab, sometimes known as Paralithodes camtschaticus, may reach a length of 10 feet (3.05 meters) and a weight of 25 pounds (11 kilograms).
Legs alone may stretch up to be five feet long, to put it into perspective. Their black red carapaces only reach around 11 inches (0.3 meters) in length, and their legs make up the majority of their body size.
The abdomens of king crabs are so distinctive that they’re often referred to as the animal’s “tail,” making them more interesting. At the rear of the shell, the “tail” is formed like a fan and positioned.
Each pair has its own set of responsibilities because their legs are so long. Five sets of legs are present on a king crab, however walking is limited to the centre set. The pinchers are found in the front two claws, with the right pincher being the most powerful. The sperm transfer and cleaning of embryos are aided by the back two legs, which are small and tucked beneath the carapace.
5. Florida Stone Crab
These crabs are found from Connecticut to Belize along the western North Atlantic Ocean, despite their name, “Florida” stone crab. Off the coast of Louisiana, the Bahamas, and in salt marshes in Georgia and South Carolina, they are most often found.
Since they can regrow missing limbs, sea crabs have an edge over predators. They may simply leave their limb behind if they are attacked by a predator, such as a grouper. Surprisingly, they will grow back their limbs as well as being stronger than before.
Stone crabs are a popular dish at restaurants because of their flavor, which is described as a combination of lobster and shrimp.
Crab is a common ingredient in diets all around the globe, but not all crabs are edible. There are poisonous crabs out there, folks.
6. Xanthid Crabs (Mosaic Crab, Toxic Reef Crab, & Shawl Crab)
The Xanthidae family of crabs, which includes a group of crabs with black-tipped claws, contains the majority of toxic crabs. The crabs don’t make the poisons themselves, and not all of this family’s crabs are poisonous. Since some crabs in the same species are non-toxic, scientists assume that the poisons come from the crab’s meals or symbiotic bacteria.
Crab poison cannot be transferred via touch since they do not have spines and cannot bite. As a result, you can only be poisoned if you eat them.
Saxitoxin and tetrodotoxin, two of the most deadly substances found in nature, may be held by Xanthid crabs in their muscles and egg masses. In reality, half a milligram is all it takes to kill an adult human. These chemicals are that dangerous.
Since the toxins are heat stable and stay in the crab’s tissues after being cooked, even cooking these crabs does not eliminate them.
These crabs are only found in Australia, so they’re not a big deal for most people’s diets. These crabs are generally tiny and don’t pose a danger of being confused with those used for eating.
7. Emerald Crabs
Because of their fondness of bubble algae, Emerald Crabs are a saltwater crab that is commonly utilized in home aquaria. The coloration of these crabs is what makes them appealing to humans, but it is also what signals their toxicity. They are one of the most vivid species of crab.
Due to their consumption of bubble algae, emerald crabs are a popular saltwater crab in home aquariums. The coloration of these crabs is what attracts humans to them, but it is also what warns against their toxicity. They are one of the brightest species of crab.
They are not typically a danger to humans, despite the fact that they are poisonous. They must be consumed to be harmful, much like the crabs in the Xanthid family. Emerald crabs are not a suitable food option because they only grow to be 5 centimeters (2 inches) in diameter.
Emerald crabs can be found in the Gulf of Mexico’s tropical Caribbean waters in their natural environment. They like to hide in caves, rocks, and corals’ cracks.
8. Floral Egg Crab
These are a kind of poisonous crab with black-tipped claws that is separate from the others. They have a thin brown or black, oval-shaped shell and are found in the Indo Pacific Ocean. Their carapace is covered with lace-like white or yellow lines. They like to decorate their shell with items they find around the house.
It has huge, oval-shaped pincers and a shell that is considerably broader than it is long. They are about 10 centimeters (4 inch) long when they are still tiny.
They have incredibly narrow legs and do not have swimming legs, hence it is clear that they cannot travel far. Instead, they move around in the same environment using their legs.
Floral egg crabs can be found across Southeast Asia and the Indo-Pacific, down to Australia, and are more widely distributed.
The Largest Crab
Crabs come in a variety of shapes and sizes, with certain species possibly being larger than others. The Japanese spider crab blows away the competition when it comes to a body that is bigger than all the other crabs.
9. Japanese Spider Crab
You were probably thinking that the king crab sounded ginormous, but the Japanese spider crab dwarfs the king crab by comparison.
This species is not only the world’s biggest crab but also the world’s biggest crustacean. It is the world’s largest of 60,000 crustacean species.
Spider crabs from Japan may grow up to 16 inches (0.4 meters) in length. One big crab can be made by combining their ten legs, each of which is 18 inches (0.5 meters) long. These gentle animals may weigh up to 42 pounds (19 kg).
Their spiky, oval carapaces are painted orange and white, making them stand out. Because of their sea-floor dwelling, they can blend in with the rocks.
The Pacific coast of Japan is home to spider crabs, which live at depths ranging from 164 to 1,640 feet (50-500 meters). Temperatures of around 50 degrees Fahrenheit (10 degrees Celsius) are ideal for them.
The Smallest Crab
The Japanese spider crab, the world’s biggest crab, has just been discovered. The tiniest crab in the world must exist on the opposite end of the spectrum as well.
10. Pea Crab
The bodies of pea crabs are just up to 0.75 inches (0.02 meters) long, making them the smallest crab species on Earth.
Any crab in the genus Pinnotheres, which includes polychaetes, mollusks, and echinoderms, is referred to as a “pea crab.” The crab, unlike a parasite, gets protection from the creature it lives in rather than anything from it.
Another kind of pea crab that lives in the mantle cavities of clams, mussels, and scallops is Pinnotheres maculatus. In the shells of coastal European waters, Pinnotheres pisum lives in mussels and cockles.
Some crabs live on land permanently or are semi-terrestrial, while others live in the water.
11. Blue Land Crab
The huge land crab is the biggest semi-terrestrial crab species in Florida, and the blue land crab is another name for it. Their carapace is only about 6 inches (0.15 meters) in diameter, despite their name as the “giant” land crab.
These crabs begin their lives dark brown, purple, or orange in color and develop to a lighter brown, purple, or orange coloration as they age. Their color will turn blue-grey as they get older. One of the pincers of a crab, like that of many other species, is bigger than the other.
Blue land crabs, who spend the majority of their time on land, require water to survive and reproduce. Apart from these cases, these land crabs live in burrows that are several feet deep and create them.
Blue land crabs require water to drink and reproduce since they spend the majority of their lives on land. These land crabs, in addition to the examples above, stay on the ground and dig several-foot-deep burrows.
These land crabs are mostly vegetarian, unlike many crabs. They prefer to eat leaves, berries, flowers, fruit, and vegetables over animal matter like other crabs do.
12. Coconut Crabs
The coconut crab is the world’s biggest terrestrial animal, while the Japanese spider crab is the world’s biggest crab. It is the world’s biggest terrestrial arthropod, as well as the world’s biggest terrestrial crab species.
Coconut crabs have three-foot-long legs and are enormous. The crabs can also carry weights as large as 62 pounds (28 kilograms), which is particularly impressive for their pincers.
They do not require shells for the rest of their lives because of their massive size. Unlike the other crabs on our list, coconut crabs have to seek for empty shells since they are a kind of hermit crab.
Coconut crabs abandon their shell when they grow large enough, and their tough exoskeleton surface provides them with protection.
The Indo-Pacific is home to these crabs. They may be found in the Caribbean’s Gambier Islands, as well as off the coasts of Africa and the Eastern Pacific Ocean.
Coconuts, a delicacy that they seek out by climbing trees, are their favorite food to feast on. Other foods, such as fruit, nuts, seeds, and even animals will be devoured by them. Coconut crabs will hunt rats, birds, and even other crabs, unlike most crabs who eat mostly dead animals.
13. Hermit Crabs
Hermit crabs come in over 800 different species across the globe. The majority of hermit crabs live in the water, however there are several kinds of terrestrial hermit crabs that are commonly kept as pets.
They are not genuine crabs, despite the fact that they are referred to as crabs. Instead, they resemble lobsters more closely. An animal with an exoskeleton that is consistently hard and can produce its own shell is called a true crab.
Hermit crabs have a hard exoskeleton on only the front half of their bodies, unlike true crabs. A shell that they steal from another animal needs to be used to protect the tail on the opposite side of their body. They normally look for discarded shells, but if they can’t find any, they kill snails and other gastropods to harvest their shells.
Hermit crabs have a hooked tail that allows them to secure themselves in the discarded shell because their shells do not belong to them. In order for their bodies to grow, they regularly need to shed their shell.
Crabs Kept in Aquariums
14. Fiddler Crabs
One of the most common types of crabs kept as pets in aquariums is fiddler crabs. They are just 2-3 inches (0.05-0.07 meters) long and extremely fascinating to watch as they grow. Males have one pincer that is substantially bigger than the other, and they have two pincers on their front legs. To attract a mate or scare predators, this pincer is moved in a dancing motion.
Fiddler crabs come in a variety of colors, from pale to vivid, and some are even blind.
There are a few things you should understand if you want to keep a fiddler crab as a pet. They can’t live in completely fresh or salty water, so they need brackish water to survive. They need access to land since they are semi-terrestrial. When they want to emerge from the water, you’ll need to provide them with plenty of rocks or decor.
Because fiddler crabs need access to air, many people prefer to keep them in a species-only tank since they live in brackish water. Brackish fish, such as mollies, may be kept in the submerged half of the tank if you have a big enough aquarium.
15. Thai Micro Crab
One of the most gorgeous freshwater aquarium crabs is Thai micro crabs. Their bodies are barely 0.4 inches (0.01 meters) wide, making them one of the tiniest animals on Earth. They are difficult to see since their bodies are virtually transparent and have a light grey-brown color. They like to blend in with the environment.
Small aquariums less than five gallons are optimal for micro crabs. They are best kept with other micro crabs or shrimp that will not pose a threat to them, despite the fact that they may work with some docile fish species. Unfortunately, because of their tiny size, they are vulnerable to bigger predators.
Thai micro crabs are a freshwater species, and they should not be kept in brackish or saltwater aquariums, unlike fiddler crabs.
16. Anemone Crabs
One of the most common crab species kept in saltwater aquariums is Anemone crabs. Their brilliance in coloration has earned them a lot of fans. The shells have a crimson polka dot design on their edges, which are made of white porcelain.
The anemone crab uses its fan-like appendages to eat, but it has huge claws that it employs to grasp and devour bits of flesh that it finds. They use their appendages to collect minuscule particles of food from the surrounding water, flailing them around the water column like a feather duster.
They’re fascinating to watch due to their vivid coloration and fan-like appendages. Anemones, the creatures for whom they are named, are also a favorite habitat. They may live in your home aquarium without the presence of an anemone, but they will be happier with one.
Other Common Crab Species
17. Horseshoe Crab
Despite their name, horseshoe crabs are not real crabs. They’re an invertebrate that looks a lot like a crustacean, and they’re arthropods.
These creatures may reach a considerable size, yet they are frequently kept as pets in home aquariums. They may grow to be 24 inches (0.61 meters) long and 12 inches (0.3 meters) broad, weighing about 3 pounds (1 kilogram).
They prefer to live in shallow water and can be found across the Atlantic and Eastern Pacific oceans. Horseshoe crabs dwell in shallow estuaries and along continental shelves, preferring not to go into deep water. From Maine to the southern Mexican Yucatan peninsula, they may be found.
Because it is used to test for bacterial contamination in drugs, horseshoe crab blood is incredibly important in medicine. Before they are returned into the water, they are frequently collected for a blood draw. Unfortunately, though, the harvesting process has had a negative impact on horseshoe crab populations since 15-30% of crabs released do not survive.
18. Brown Crab
Brown crabs are brown in color and have a reddish tone to their skin, as the name suggests. Their shells become a lighter brown color after they are cooked and served to eat. In contrast to their black claws, they have black tipped claws.
The margins of the shells of small crab are formed in a wave-like pattern and are formed like an oval. Their shells’ edges are termed a “pie-crust” occasionally.
The carapace of these crabs, which measure 6-9 inches (0.15-0.22 meters) in length, is on the larger end of the spectrum for most crabs. They may weigh up to 6.6 pounds (3 kg).
The North Sea, Northern Atlantic Ocean, and Mediterranean Sea are all home to these crabs.
19. Horsehair Crab
Brown and orange crabs with orange dots cover their bodies. Their shells are rough, and they have spiky hairs all over their body.
They are just about 3.9-4.7 inches (0.09-0.12 meters) long and weigh no more than 2.2 pounds (0.99 kilograms), making them appear to be on the smaller side.
These crabs may be found around Alaska and northern Japan, particularly in colder waters. These are bottom-dwelling creatures that reside in water as deep as 350 meters (1,148 feet), where they dwell at the lowest depths.
20. Peekytoe Crab
The peekytoe crab, also known as the Atlantic rock crab, is a cold-water crab. The crab’s brown coloration with purple spots on its shell earned it the moniker “Peekytoe,” which is a term for the pointed shape of its legs.
With a diameter of roughly 5.25 inches (2.4 meters) long, this crab is a reasonably sized crab.
Peekytoe crabs used to be a problem for lobster fishermen, who caught them in their nets. They were a common crab sought after by chefs until about 1997, when they were thrown back as an nuisance bycatch.