Buying shrimp online means trusting a courier with a living animal sealed in a bag of water, and the packaging is the whole difference between a lively arrival and a bag of casualties. We've posted a lot of shrimp and unpacked plenty sent to us, so this is what good looks like from both ends of the parcel. Learn to read a seller's packaging before you order, because it tells you as much about them as the shrimp themselves do.
What shipping actually has to survive
Three things work against a shrimp in transit: temperature swings, waste building up in a tiny volume of water, and time. A bagged shrimp sits in maybe a cupful of water that cools or warms with the parcel, slowly fouls with the shrimp's own ammonia, and loses oxygen — all while a courier moves it across the country. Good packaging buys time against all three; careless packaging loses the race.
Cherry shrimp help their own cause here. They're hardy, and their oxygen demand is modest compared with a fish of the same size, which is exactly why they travel better than most livestock in the post. But hardy is not invincible, and a 24-hour journey in the wrong box still arrives full of dead shrimp. Everything below exists to stretch that safe window long enough for a next-day courier to do its job.
Breather bags vs standard bags
There are two ways to bag a shrimp, and both can be done well.
Breather bags are made from a special film that lets gases pass straight through the bag wall — oxygen in, carbon dioxide out — while holding the water in. They're filled almost completely, with no air gap needed, because the shrimp effectively breathe through the plastic. For a long or uncertain journey they're the gold standard: gas exchange never stops, so the shrimp can't suffocate even if the parcel is delayed a day. The one rule that comes with them is that the film has to travel exposed to air. Sealed inside an airtight outer bag or wrapped tight in tape, a breather bag can't breathe — and sellers and buyers do occasionally get this wrong.
Standard poly bags are the classic method: roughly a third water to two-thirds air, doubled up and sealed. Packed properly they're perfectly safe for a next-day trip. Packed carelessly they have one real failure mode — the corners. A shrimp can wedge itself into a taut corner and get stuck, so a careful packer rounds the corners off, ties a band across them, or uses a purpose-made shrimp bag, leaving nowhere to get trapped. A good standard bag also has something inside to cling to, which brings us to the next point.
Neither bag is a red flag in itself. Careless use of either one is. A breather bag stuffed inside an airtight sleeve, or a standard bag with sharp empty corners and nothing to hold onto, is the tell that someone bagged shrimp like they'd bag a goldfish.
What else belongs in the bag
A good shrimp bag is never just shrimp and water. Look for a clump of something to grip — Java moss is the usual choice, occasionally a floating plant or a piece of catappa (Indian almond) leaf.
That clump does two jobs. It gives the shrimp something to hold so they aren't tumbled around loose for the whole journey, which cuts stress sharply. And it carries a little biofilm, so there's something to graze if the trip runs long. It's a small touch that quietly separates someone who ships shrimp regularly from someone doing it for the first time.
You won't see food in the bag, and you shouldn't. Feeding before a journey only loads the water with more waste, so good sellers fast their shrimp for a day or two before posting to keep the bag cleaner. A bag that looks empty apart from the moss is exactly right.
The box: insulation is the point
The bag travels inside a box, and that box is doing one job above all others — holding temperature steady. A bare bag rattling around in a plain cardboard box is at the mercy of whatever the van and the doorstep throw at it. A proper shipment uses an insulated box, typically a polystyrene liner inside the cardboard, which slows heat moving in or out and keeps the shrimp inside a safe band whether the day is warm or cold.
Inside, the bag should be cushioned so it can't roll or burst — packing paper, bubble wrap, something to stop it sloshing about. You want the bag arriving intact and not leaking. Together, the insulation and the padding are why a well-packed shrimp parcel feels reassuringly over-engineered when it lands on the mat. That's a seller doing it right, not wasting materials.
The cheapest end of the market is where this corner gets cut. A bare bag posted in a padded envelope with no insulation at all is a hallmark of a rushed sale, and it's one of the standing risks of the eBay and Facebook shrimp market — worth knowing before a bargain listing tempts you.
Heat packs, and the summer problem
In the colder months a good seller adds a heat pack — an air-activated pad that gives off gentle warmth for a day or more — to hold the box above the danger zone. Two details mark out someone who knows what they're doing. The pack is positioned so it warms the air in the box rather than pressing against the bag, because direct contact can cook the shrimp on that side. And it's matched to the length of the journey, so it's still working when the parcel lands rather than spent halfway through. Winter shipping with no heat pack, on a cold-snap week, is a gamble the shrimp usually lose.
Heat is the harder problem, because there's no cold pack that's safe to sit next to livestock. In a summer heatwave the honest answer is not to ship at all. Good sellers watch the forecast and simply hold orders over extreme weeks, hot or cold, until the weather turns kind — the weather rule we cover in where to buy cherry shrimp in the UK. A seller who'll delay your parcel for the shrimp's sake is one worth waiting for, not one giving you poor service.
Speed: why next-day is the whole game
Every hour a shrimp spends in a bag makes the bag a little worse, which is why the courier service matters as much as the wrapping around it. Shrimp should travel on a tracked next-day (24-hour) service, posted early in the week so there's no chance of the parcel parking in a depot over a weekend. A Friday shipment that sits until Monday has spent three days fouling, and no bag survives that gracefully.
This is worth asking about before you buy: which courier, which service, which days they post. A seller with good answers ships Monday to Wednesday, next-day and tracked, and won't post into a weekend. It's also the reason posted shrimp cost more than shrimp you collect in person — you're paying for speed, insulation and a heat pack on top of the animals themselves, which is money well spent rather than a markup to resent. The full list of what to put to a seller before ordering is its own guide: 10 questions to ask your shrimp breeder.
DOA policies: what a fair live-arrival guarantee looks like
DOA means "dead on arrival", and a live-arrival guarantee is the seller's promise to put things right if shrimp don't survive the post. Any specialist worth buying from offers one, and the terms are where you read their character.
A fair policy usually asks a few reasonable things of you. Photograph any casualties promptly — commonly within a couple of hours of delivery, sometimes still in the unopened bag — and report them the same day, so there's honest evidence before acclimation muddies the picture. It'll ask that you were in to accept the first delivery attempt, because a parcel bounced back to the depot overnight is nobody's fault but somebody has to own it. And it'll usually exclude losses when you insisted on shipping against weather advice. In return, a fair seller refunds or replaces the dead shrimp without a fuss. Our own safe-arrival guarantee is written in exactly that spirit if you want a worked example of fair terms.
What isn't fair is a guarantee hedged so heavily it never pays out: impossible photo windows, "no live-arrival cover on standard postage" while only offering standard postage, or simple silence on the subject. No guarantee at all is the biggest warning sign on this page. A seller who's confident in their packing stands behind it.
What your shrimp should look like when the box opens
Open the box somewhere calm and don't panic at what you find. Freshly arrived shrimp look nothing like the listing photos, and that's completely normal.
Expect the water to be cooler than your tank and possibly a little cloudy. Expect the shrimp to be pale, washed out and mostly still — some clinging to the moss, some sitting on the bottom of the bag. A shrimp that flicks or scoots when you lift the bag is alive and fine; colour and confidence return over the next day or two once it's in stable water. What you're checking at this stage is simple: are they alive and responsive, and how many, if any, didn't make it. Take your DOA photos first if you need them.
Then don't rush the next part. However good the packaging, the move from bag water into your tank is the single riskiest moment of the whole trip, and it's the part entirely in your hands — drip acclimation is how you get them across without a shock, and it matters most precisely because they've just travelled. Knowing what healthy shrimp look like as they recover helps you tell a shrimp that's simply settling in from one that's genuinely failing over those first couple of days.
Our own colony is rebuilding at the moment, so we're not shipping today — but when it reopens, every order goes out packed to exactly this standard, and the waitlist hears first when the next graded broods are ready.
FAQ
How are cherry shrimp shipped in the post?
In a sealed bag of water — either a breather bag or a standard poly bag with an air pocket — usually with a clump of moss to cling to, cushioned inside an insulated, polystyrene-lined box. In winter a heat pack goes in to hold the temperature up. The parcel then travels on a tracked next-day courier so the shrimp spend as little time in the bag as possible.
Are breather bags better than normal bags for shrimp?
For long or uncertain journeys, yes. Breather bags exchange gas through the bag wall, so shrimp can't suffocate even if the parcel is delayed. Standard bags with an air pocket are perfectly safe for a next-day trip when they're packed well, with rounded corners and moss inside. The bigger question isn't which bag was used but whether the seller used either one carefully.
Do shrimp need a heat pack when posted?
In the UK's colder months, yes. A heat pack holds the box above the danger zone on a journey that would otherwise chill the shrimp, and it should warm the air in the box rather than press against the bag. In a summer heatwave there's no safe cooling equivalent, so the right move is to delay shipping until the weather calms rather than post into extreme heat.
What is a shrimp DOA guarantee?
DOA stands for "dead on arrival". A live-arrival guarantee is the seller's promise to refund or replace shrimp that don't survive shipping. A fair one asks you to photograph casualties promptly, often within a couple of hours, and to have accepted the first delivery attempt, and it usually excludes losses when you insisted on shipping in extreme weather. No guarantee at all is a serious red flag.
What should shrimp look like when they arrive?
Pale, still and underwhelming — that's normal. The water will be cool and maybe a little cloudy, and the shrimp will look washed out, some clinging to the moss. What matters is that they respond when disturbed. Colour and normal grazing come back within a day or two of getting them into stable water through slow acclimation. Photograph any that didn't survive before you start.