Parasite Eggs On Crab Legs (How To Spot Them And Can You Still Eat Them?)

When it comes to eating creatures from the sea, it is all too easy to get confused about the safest way to eat them!

Many types of aquatic creatures, including crabs, can be contaminated with parasites. Some of these are completely harmless to humans, whilst others should be avoided at all costs.

So, what if you see black spots on your crab legs—are these parasites, and can you still eat them? The tiny black spots on crab legs are the eggs of the marine leech, and they are normally killed when the crab is stored on ice and then cooked. These spots are completely harmless to humans but can look quite unsightly if you are serving whole crab legs at a dinner party.

Want to find out more about how to ensure crab legs are safe to eat? Keep reading to find out everything you need to know about this delicious and highly nutritious aquatic creature!

What Are Crab Legs?

Crabs are water-dwelling creatures that are found all around the world, in oceans and fresh water, and on land.

In fact, there are over four thousand different types of crab across the globe. These incredible creatures actually have prehistoric origins, dating back as far as the Jurassic period!

Crabs are a type of aquatic creature that is classified as a crustacean, meaning that their body is covered in a thick shell.

They have several pairs of legs and a well-developed set of claws with sharp pincers. Crabs are notorious for walking sideways, as it is easier for them to get around this way!

Crabmeat is a highly sought-after delicacy, and these aquatic creatures have been enjoyed by humans for centuries. They can be eaten in many ways; however, getting through the thick shell to pick out the meat is not an easy task!

The meat from the body, legs, and claws of the crab can be eaten, and the amount of meat varies according to the type of crab. The meat is cooked inside the shell, which is then cracked open, and the meat picked out.

And while the brown meat inside the shell is very tasty, there is nothing quite as delicious as the sweet, white meat contained inside the claws and legs of the crab.

Crab legs can be bought either fresh or frozen, and they are normally pre-cooked. This means that all you need to do is reheat them at home.

Cooking the crab as soon as possible after it is caught locks in the fresh flavor, and it is then chilled on ice or frozen to keep it in prime condition.

Make sure to check carefully that your crab legs are definitely cooked though, as raw crab meat is not something that we’d advise eating!

Crab Legs With Black Spots

It is not unusual to purchase crab legs with black spots on them, and many people don’t even realize that these black spots are not a normal part of the crab itself! So, what are these black spots?

But sometimes you will come across some crab legs with tiny black balls stuck to the surface of the shell. These are normally next to each other, in a string or cluster of black dots.

These eggs are laid by sea creatures called marine leeches. They lay their eggs on the hard outer shell of crabs, in an ingenious display of reproduction.

Firstly, the crab is a relatively safe place to lay eggs, and laying them on a crab rather than a rock gives a greater chance of survival.

The crab also moves around the seafloor, enabling the population of marine leeches to spread over a wider area.

Whether you find this tale fascinating or utterly disgusting, there is no doubt that it is a clever way for the marine leeches to ensure the survival of their species!

Some crabs will also have black marks on their legs which are old wounds, sustained during territorial fights. Yes, that’s right, these remarkable creatures will have a battle to claim their section of sea bed!

When the wound heals, a black mark is left behind. These scars are normally superficial, but occasionally they will extend right through the shell and into the flesh underneath.

So, if a lot of crabs are infected with parasite eggs, is this something we should be worried about? And are they safe to eat? Time to find out more!

How To Tell If Spots On Crab Legs Are Parasite Eggs

When cooked, crab legs are a reddish-brown color, with paler areas of the pinkish-colored shell near the joints of the legs. Raw crab legs are brown or green, and these should be cooked before consumption.

Most crab legs are uniform in color and are a thing of beauty. But what if you’re served a plate of crab legs that have black spots on them—are they parasite eggs, or something else?

The parasite eggs on crab legs are very easy to recognize. They look like tiny black dots and are normally laid in small clusters or lines.

If you pick away the black surface of the egg, you will see a tiny white worm underneath. This is the larvae of the marine leech, which will have been killed when the crab was cooked.

You may also occasionally see the marine leeches themselves on the crab legs – these are also very small, and may easily be overlooked.

Are Crab Legs With Black Spots Safe To Eat?

If crab legs have black spots on the outer shell, these are most likely an accumulation of kanibiru, the eggs of a leech-like parasite.

Whilst this might seem a bit yucky to many people, in the world of crab cuisine they are actually an indicator of quality!

The reason for this is that in the regions where the best crabs are caught, the sea bottom tends to be muddy and there are few rocks available. This means that the eggs are more likely to be laid on the shell of the crabs.

Another reason is that an accumulation of parasite eggs means that it is probably a long time since the crab last molted its shell. This means the crab will be meatier, with dense, full flesh inside the claws.

Because of the way crabs are processed, stored, and cooked, it is unlikely that these parasite eggs would survive.

Freshly caught crab is normally packed on ice or frozen, which would kill off most of the eggs. The remainder would be destroyed during the cooking process.

The marine leech cannot contaminate the flesh of the crab, and this part of its life cycle takes place entirely on the shell of the crab.

But, harmless as they may be, once you’ve spotted them it is easy to get a bit grossed out by these tiny parasites!

Can You Remove Parasite Eggs From Crab Legs?

If you’ve bought some crab legs from the fish market, you might be dismayed to find that they are covered in black spots. These parasite eggs are completely harmless to humans, but they do not look very appetizing!

So, can you remove parasite eggs from crab legs?

You can scrape the black dot off the leg, but this will reveal a small worm underneath, which is very difficult to remove. Even if you can scrape it off, it will leave a scar or mark on the leg.

And as crab legs can often have tens or even hundreds of black dots on them, removing them by hand is a very laborious process!

This means that marine leech larvae eggs are not normally removed from crab legs. They can be cooked and eaten with the eggs still in place, without any risk of harm to humans. 

However, if you’re serving crab legs whole, such as in a bisque, try to select ‘clean’ crab legs that are free from parasite eggs.

Related Questions

Now we’ve got those black spots on crab legs all figured out, let’s take a look at some other crab-related queries!

Can you eat raw crab?

Crabmeat is never eaten raw, as it can be potentially harmful to human health. The texture and flavor of crab meat also change considerably when it is cooked, making it more palatable.

Raw crab meat can contain several microorganisms that may be detrimental to human health. These include a type of lung fluke called Paragonimus westermani.

Raw crab meat may also be contaminated with bacteria including Vibrio parahaemolyticus and Vibrio cholerae.

The flesh of raw crab can be watery and mushy, and many people find this unappetizing. Crabmeat develops a much more appealing flavor and texture when it is cooked.

So, not only will raw crab meat most likely give you a nasty stomach upset or long-term lung problems, but it also doesn’t taste particularly pleasant either!

Is imitation crab raw or cooked?

When you buy imitation crab meat from the store, it is already cooked. Imitation crab meat is never sold raw, so you don’t need to panic that you need to cook it first. In fact, it would be highly dangerous to eat imitation crab raw!

Imitation crab is made from reformed fish meat that has been seasoned and flavored to taste like crab meat and then cooked. You can enjoy eating imitation crab without any further preparation, as it has already been cooked.

The imitation crab meat you purchase is pre-cooked and perfectly safe to eat in its current state.

It must be stored safely and correctly in a refrigerator, otherwise, it may be unsafe to eat. Never eat imitation crab which has been left out at room temperature.

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