Your shrimp arrives at the table. You’re salivating, ready to dive in. But then your gaze narrows in on the thin black line along the backs of each shellfish. As you’re about to rip into some prawns, the thought of “is that…shrimp poop?” and, perhaps more importantly, “is it okay for you to eat it?” passes you by.
The thought of eating poopy seafood makes me sick, but I didn’t want to give up shrimp just yet. I wanted to talk to food safety experts to find out what was really going on. Is that dark line really what it looks like? If so, should you be worried about eating it? Read on to find out what experts say.
If you’ve ever prepared or eaten shrimp, you’ve likely noticed a thin black line running along the back of the shellfish. This mysterious marking causes many home cooks to pause and wonder – what is that? And should I remove it before eating my shrimp?
This black stripe found on raw shrimp is actually the crustacean’s digestive tract. It runs the length of the shrimp’s body along the dorsal side and contains the intestines and other digestive organs. The shrimp relies on this vein to process the food it consumes from the ocean floor
While it may look unappetizing to some, the black vein on shrimp itself is not harmful or dangerous to eat. However, here is some helpful information about what exactly it contains and whether or not you need to remove it when preparing shrimp:
What Is Inside the Black Vein?
The black vein, also called the sand vein, digestive tract or intestinal vein, contains:
- The stomach and midgut
- The intestine
- Waste and digestive fluids
- Partially digested food particles
- Grit like sand
As bottom-dwelling creatures, shrimp eat a variety of foods found on the ocean floor including plankton, algae, small worms and fish. The dark contents of the vein come from this unique diet.
The vein appears black from this mixture of digested foods, waste, sand and intestinal fluid. The grittiness comes from sediment and sand shrimp ingest while scavenging the seabed.
Is the Black Vein Poop?
In simple terms, yes the black substance inside the vein is essentially shrimp poop. The intestine carries wastewater and feces through the digestive tract, which gives the vein its dark, muddy appearance.
Some people refer to the black vein as the “poop chute” or “poop vein” for this reason. So you may want to keep that in mind when deciding whether or not to devein your shrimp!
Is the Vein Safe to Eat?
While the idea of eating shrimp intestines and feces may seem rather unappetizing, the black vein itself poses minimal health risks if the shrimp is cooked properly.
The primary safety concern with eating shrimp veins comes from potential bacterial contamination. Like other seafood, raw shrimp may contain bacteria that can cause foodborne illness.
However, thoroughly cooking the shrimp to an internal temperature of 145°F kills any dangerous bacteria that may be present. This includes pathogens potentially found inside the vein.
So while the intestinal contents may look unsavory, they are generally safe to consume after thorough cooking. The vein becomes an issue of taste, not necessarily food safety.
Should You Remove the Black Vein?
Whether or not to remove the black vein before cooking comes down to personal preference:
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Leave it in – This is perfectly safe if cooking the shrimp properly. It saves time prepping. The vein may add extra flavor from digestive juices.
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Remove it – This avoids the gritty, poop-like texture. It creates a cleaner presentation. The shrimp taste milder without the vein.
Many recipes call for deveining shrimp before use. This involves simply using a paring knife to slice open the back of the raw shrimp. Then use the tip of the knife to gently pull out the black intestine. Rinse under cool water.
Deveining is easiest when the shrimp is still raw and the vein is most visible. Once cooked, the vein shrivels up and becomes more difficult to remove.
Tips for Preparing Shrimp with the Vein
If you don’t mind leaving the black vein intact, here are some tips for safely enjoying shrimp this way:
- Purchase fresh, raw shrimp from a reputable seller
- Store shrimp properly chilled at 40°F or less
- Thoroughly cook shrimp to an internal temp of at least 145°F
- Cook it in flavorful dishes that disguise vein’s gritty texture
- Avoid eating raw shrimp sashimi with the vein still in
Casseroles, curries, pasta dishes, and tacos help mask the vein’s texture. Quick sautéing, broiling or grilling may leave it more noticeable. Adjust your cooking method and recipes accordingly if leaving the vein intact.
Common Questions about the Black Vein
Here are answers to some other frequently asked questions about the mysterious black stripe found on shrimp:
Is it the shrimp’s blood?
No, shrimp have clear blood unlike humans. The black color comes from digested contents inside the intestine.
Are there veins in the shrimp’s legs or tails?
No, the vein runs just along the back region of the body. The legs and tails are vein-free.
Do all shrimp have this vein?
Yes, it is naturally present in all shrimp as part of their digestive system. However, it may be more visible and prominent in certain varieties.
Should you remove it for aesthetic reasons?
That’s up to you! Many people prefer the look of cleaned, deveined shrimp. But leaving it in is perfectly safe when cooked.
What’s the easiest way to remove it?
Use a paring knife to slice along the back of raw shells. Use the tip to lift out the vein and rinse well. Removing it from raw shrimp is much easier than cooked.
Is it more common in wild vs farmed shrimp?
Wild shrimp likely have a more prominent, grittier vein since they eat a diverse ocean-floor diet. Farmed shrimp may have a milder vein.
Can eating shrimp’s poop make you sick?
Having established that the dark line is the shrimp’s intestines (okay, its poop), should you be afraid to eat it? It might look gross, but most people agree that it’s safe to eat as long as you cook it properly.
“Eating the shrimp’s digestive tract doesn’t make you sick—as long as you cook it thoroughly,” says Dr. Love. That means steaming, baking, frying, or whichever way you’re craving it, until it reaches 145°F. At this internal temperature, the shrimp will take on a firm texture.
That’s not to say you can’t get sick from eating shrimp in general. You can, but Dr. Paul says that eating shellfish raw or not cooked enough is usually what makes people sick. Love. For instance, just like ground beef, raw shrimp can contain bacteria like E. coli. But if you cook it all the way through, the heat will kill the bacteria and any other pathogens that could be harmful before they can mess up your digestive tract. So if you want to eat shrimp with the vein still in it, you might want to avoid raw shrimp sashimi and instead try them in a curry, stir-fry, garlicky pasta, or zesty taco.
What’s that black line in shrimp?
The dark line running through the backs of shrimp goes by many names—the dorsal tract, back vein, or sand vein, Tori Stivers, MS, a seafood specialist at the University of Georgia Marine Extension and Georgia Sea Grant, tells SELF. The marking is made up of the shellfish’s stomach, midgut, and intestine. Those structures support the crustacean’s digestive process, so yes, that black stuff is the shrimp’s waste, she says.
As for what you’re actually seeing there? Shrimp are called bottom feeders for a reason: They munch on foods found in the muddy depths of the ocean, like plankton, worms, microscopic animals, and various types of organic debris like sand. So that black line is likely a combination of all those things in various stages of digestion, Dave Love, PhD, a senior scientist at the Johns Hopkins Center for a Livable Future, tells SELF.