Ghost shrimp (Palaemonetes paludosus) are also known as glass shrimp or grass shrimp, and they belong to the Palaemonetes family. Commonly found in pet stores as feeder shrimp, these transparent invertebrates are easy to manage on their own or as part of a peaceful community aquarium. With their unique appearance and wide availability, these dwarf shrimp appeal to novice and experienced aquarists alike.
Ghost Shrimp: Origin
Ghost shrimp are native to rivers and lakes of the southeastern United States. They were first described in 1850, and they’ve been popular since the first aquariums. These hardy little invertebrates tolerate a wide variety of environmental conditions, and they’re found in both fresh and brackish waters.
In fact, scientists have documented ghost shrimp surviving in waters with salinities as high as 55ppt (parts per thousand); ocean water has a salinity of just 35ppt! This is why it’s important to confirm that your species is freshwater before you bring your shrimp home, or they may not survive introduction to the tank.
Ghost Shrimp: Description
As the name implies, ghost shrimp have a transparent appearance that allows them to blend in with their surroundings – an important defense when you’re on the menu for so many other creatures! Different species have various colored spots along their backs, but the majority of the shrimp remains translucent. If you come across a white ghost shrimp at the store, avoid it – it’s about to die.
Ghost shrimp have two pairs of antennae – one long and one short – that are very sensitive. These are sensory organs that detect information from the environment around them, aiding in navigation, communication, and determination of water conditions.
The body is divided into two segments: the cephalothorax and the abdomen.
The cephalothorax (“head chest” is the Latin translation) is the front portion and comes to a point called the rostrum. Ghost shrimp have eyestalks on either side of the rostrum that are capable of independent movement. Behind the eyestalks, the transparent carapace covers the remainder of the cephalothorax and protects the shrimp’s major organs. Beneath the carapace are five sets of walking legs, or peripods, two of which have tiny claws to aid in the manipulation of food.
The abdomen has seven overlapping shells; the overlapping design allows the shrimp to curl the tail under its body. Beneath the abdomen are five pairs of swimming legs, or pleopods. Females carry their eggs beneath their abdomen, and they use the pleopods to fan oxygen onto the eggs.
The final abdominal plate comes to a point called the telson. Four uropods fan out from the telson to form the tail. A shrimp can curl the tail rapidly in order to swim backward away from threats.
Ghost shrimp are in the dwarf category: they only get to be about 1.5-3 inches (3.8-7.6cm) in length, and they’re about the width of a pencil eraser. They are sexually dimorphic with females growing larger than males; females also develop a “saddle” or crest on their cephalothorax when mature.
Ghost Shrimp: Molting
Invertebrates like ghost shrimp possess an exoskeleton they must molt in order to grow. When young, shrimp molt about once a week, but as they mature, they slow down to once a month depending on how much they’re eating and growing. Molts in the tank are a good sign as it means the shrimp are healthy and growing.
Shortly before molting, a shrimp will appear more opaque due to the new shell forming under the old. As they molt, they will repeatedly curl their tail beneath their abdomen to attempt to loosen the old shell. The shell will split where the abdomen meets the cephalothorax, and the shrimp will pull itself from the front and flick the molt away. This happens quickly, and you’re likely to miss it.
A molt will appear completely clear, like glass, and you may confuse it for a dead shrimp. For clarification – dead shrimp turn a whitish-pink, almost like they’ve been cooked. Don’t remove molts from the tank as the shrimp feed on the discarded shell; it provides needed minerals and nutrients. Also, don’t be surprised when you can’t locate the freshly-molted shrimp. In their new SOFT shell, they’re vulnerable, and they’ll hide until it hardens.
Ghost Shrimp: Tank Set-Up
Ghost shrimp are small, but that doesn’t mean a tiny tank is acceptable. A 5-gallon tank is as small as you should go, but larger is better and easier to cycle. Ghost shrimp can be social, but if they’re kept in tight quarters, they’ll develop aggression issues with one another. A rule of 3-4 shrimp per gallon is safe; if you’re going to keep them with fish make sure you plan for that extra biomass appropriately. You’ll want to invest in a good cover for your tank as ghost shrimp are notorious jumpers.
As with any aquarium, a filter is a necessary element, but special care is needed when you have ghost shrimp. Due to their small size, intakes pose a vacuum hazard, and you’ll need a sponge over the intake valve to protect your shrimp from being sucked into the mechanism. One way to avoid this hazard is to purchase an in-tank or sponge filter. These filters provide appropriate water flow levels – ghost shrimp aren’t the strongest swimmers – without the risk of suction.
Sand and fine-grain gravels are the best choices of substrate for these invertebrates. Ghost shrimp like to burrow, and larger gravels will not only prevent this, they can cut into the shrimps’ exoskeletons. You don’t want to damage your shrimp or their sensitive antennae.
Ghost shrimp love plants, and in the wild they spend the majority of their time scouring for plant detritus. Plants not only provide nourishment for your shrimp, they also provide hiding places to help them feel more secure, particularly after a molt. Some ghost shrimp favorites include:
- Anubias nana
- Java fern
- Java moss
Ghost shrimp tolerate a wide range of water conditions, but if you want them to thrive and remain healthy for as long as possible, your best bet is to mimic the conditions found in their natural habitat. The following table represents the optimal water conditions for ghost shrimp:
Higher temperatures have the potential to accelerate growth and reproductive rates, while lower temperatures affect your shrimps’ immunity and make them more susceptible to disease. A healthy GH is important to ensure your ghost shrimp continue to molt without a problem. If you find you have soft water, you can add a mineral supplement such as SeaChem Equilibrium or Weco Wonder Shells, or you can supplement your shrimps’ diet with cruciferous foods (those high in calcium) like spinach.
Once a week, you need to perform a 30% water change. Make sure that the added water is at the same temperature as your aquarium to avoid shocking your ghost shrimp. If you have a shrimp-only tank, a water-change is sufficient for your maintenance, but if you have a community tank, a full cleaning schedule is in order.
Ghost Shrimp: Diet
Ghost shrimp are omnivores which makes them relatively easy to feed; they aren’t picky about what appears on the menu. As members of the “cleaner” shrimp group, they prefer to scour the aquarium for algae and biofilm and sift the water column for available plant debris. You’ll want to monitor their behavior when it comes time to feed them as overfeeding can lead to excessive waste build-up in the tank.
Hungry shrimp should approach freshly dropped food within 10 minutes; if no one shows interest, then they’re full and you need to remove the food before it degrades. It’s okay to let shrimp go a day between feedings, especially if you have plants available. Always consider the size of your ghost shrimp when feeding: 1 or 2 pea-sized amounts are sufficient for 5 or 6 shrimp for an ENTIRE DAY.
The list of ghost shrimp favorites is massive, and these are just some highlights (they really will eat just about anything):
- Algae wafers
- Baby shrimp food
- Blanched vegetables (spinach, romaine, zucchini, and cucumber are good choices)
- Brine shrimp
- Fish pellets
- Flake foods
- Frozen foods (bloodworms, in particular)
- Mosquito larvae
- Shrimp pellets
It’s tempting to offer your ghost shrimp live foods, but these tiny invertebrates are poor predators so make sure you choose options they’ll be able to manage, such as brine shrimp. If you have a community tank, odds are the live food will be eaten by someone, it just won’t be your ghost shrimp.
Ghost shrimp are notoriously messy eaters, so it’s a good idea to invest in a glass feeding tray to keep your aquarium as clean as possible. They quickly learn where to find their food, and it makes your clean-up of their uneaten portion much easier.
Ghost Shrimp: Tank Mates
Ghost shrimp are comfortable on their own, though they also do well in a group. They’re peaceful invertebrates, and their diminutive size makes them a potential snack for a lot of fish. As such, you probably want to avoid any tank mates with mouths large enough to swallow your shrimp – which, unfortunately, is a pretty extensive list.
All is not lost, though. There are small, calm fish that are happy to share their freshwater aquarium with ghost shrimp. You still need to watch them around shrimp eggs and fry, but juveniles and adults are relatively safe:
- Cherry barbs
- Hatchetfish (these fish prefer to hang out at the surface – well away from your ghost shrimp)
- Otocinclus catfish
- Zebra or kuhli loaches
If you have an aquarium with goldfish, discus, Oscars, or angelfish (basically any cichlids), then you’re going to need a separate tank for your ghost shrimp because they’re not going to last five seconds. These aggressive predators view ghost shrimp as popcorn, and they’ll snap them up before you get a chance to rescue them!
If you’re interested in an invertebrate aquarium, you have a lot of options for tank mates as ghost shrimp get along well with a number of other shrimp and snails:
- Amano shrimp
- Bamboo shrimp
- Bee shrimp
- Blue pearl shrimp
- Crystal shrimp
- Gold Inca snails
- Ivory snails
- Nerite snails
- Malaysian trumpet snails
- Mystery snails
- Ramshorn snails
- Red cherry shrimp (just be careful – ghost shrimp have been known to attack red cherries)
- Red rili shrimp
- Sakura shrimp
- Snowball shrimp
- Tiger shrimp
- Vampire shrimp
- Yellow shrimp
Ghost Shrimp: Common Diseases
Ghost shrimp are scavengers which makes them susceptible to pathogens (bacteria, protozoans, and viruses) that might lurk on the same surfaces they’re scavenging. As they are translucent, such infections are easy to identify. The most common diseases to watch out for are:
- Fungal infection
- Internal bacterial infection
- External bacterial infection
Vorticella is a parasite that forms a white growth around the shrimp’s mouthparts. If left alone, the growth eventually grows to cover the entire shell, killing the shrimp. Regular salt baths can help treat this nasty parasite:
- Remove a cup of water from the tank and dissolve 1 teaspoon of aquarium salt into the cup.
- Set a timer for 45 seconds.
- Place your shrimp into the cup for those 45 seconds. Immediately return them (not the water) to the tank when the timer goes off.
- Repeat the process in a few hours.
- Repeat this over several days to eliminate the parasite.
Fungal infections resemble cotton candy floss adhering to the ghost shrimp’s shell. If the shrimp is close to molting, it’s possible the fungus will remain behind with the molt, but salt baths will prevent the fungus from boring down through the shell.
Internal bacterial infections cause the organs of the shrimp to turn pink and swollen; the shrimp may also start to turn an opaque white. Unhappily, these are almost impossible to treat. Most antibacterial treatments contain copper which is toxic to shrimp. You can attempt to find one without copper, but your best bet is to remove the infected shrimp from the tank before it spreads to the others. Prevention is your best option: try keeping Indian almond leaves in your tank; the tannins given off have some antibacterial properties.
External bacterial infections manifest as pits, holes, and ulcers in the shrimp’s shell. At the first sign of these problems, start regular salt baths. You should also make sure you’re providing adequate calcium supplementation for your shrimp to keep their exoskeleton in top shape.
Ghost Shrimp: Breeding
Ghost shrimp are relatively easy to breed, but they require a separate breeding tank if you want to raise the fry with success. If you have a community tank, shrimp fry will find themselves on the menu, and even a shrimp-only tank won’t guarantee safety since adults have no problem cannibalizing their young. Luckily, a breeding tank can be very minimalistic: fine-grain substrates and plants are all the fry require; some Java moss will provide all of the nutrients and filtration the tiny shrimplets need. If you prefer to omit the plants, make sure to use a sponge filter to protect your fry.
Female ghost shrimp should produce eggs every 2-3 weeks, but if you want to maximize your chances, consider optimizing the conditions in your tank. Raise the temperature to around 80F (26.7C) to simulate the warmer summer months that coincide with their breeding season in the wild. You can also add some chips of limestone to the aquarium to increase water hardness and provide additional minerals and calcium levels needed to produce eggs. Make sure there are plenty of plants available in the tank so your shrimp feel secure enough to want to lay their eggs. Also, make sure you have a good mix of males and females (remember, females are larger).
Females produce 20-30 round, green eggs that they attach to their legs – when they do so, they’re called “berried females.” They then release a pheromone to attract the males to fertilize the eggs; the male will swim around the tank to find her. A few days after noticing your berried females, transfer them to your breeding tank. Do so with minimal chasing around the aquarium and as little stress as possible; if the female feels threatened, she’ll drop the eggs immediately and they’ll never hatch.
After about a month, the females release the eggs at the surface during dusk or dawn (low light levels); you can then return them to the main tank to keep them from eating the fry. Ghost shrimp fry are considered “low order” – this means they have a planktonic, free-swimming stage after hatching. Some people with good eyesight can see them but others need a magnifying glass. This stage is what makes them difficult to raise as people often struggle with the proper diet, but if you have plants in the breeding tank, you’ll do just fine.
Ghost shrimp fry go through a rapid phase of growth, and they have ravenous appetites. You’ll want to make sure they have plenty of food available if you want them to survive. Some of the best options include:
- Cultured microworms (you can raise these yourself or purchase them)
- Green water algae
- Algae powder
Within a week, the baby shrimp will metamorphosize to resemble the adults, and you can switch them over to the adults’ diet. Be careful not to overfeed them, though, especially if you don’t have a filter in the tank. By 5 weeks, your fry should be large enough to join the main tank.
Ghost Shrimp: Lifespan
Ghost shrimp are often stocked in fish stores as “feeder fish” with tank conditions that are sub-optimal. They’re kept in overly high numbers with poor filtration, resulting in unhealthy shrimp that die shortly after being introduced into your aquarium – even if you didn’t buy them as feeders and have a healthy tank environment. You should always look at the conditions the ghost shrimp are being housed in before making your purchase and realize there’s a very real possibility they weren’t handled properly during transport to the store.
Unhappily, even when raised in ideal conditions with optimal care, ghost shrimp just aren’t meant to last – they only have a lifespan of about one year.
Ghost shrimp are unique invertebrates with a translucent appearance, allowing for the observation of their internal digestive processes. They are relatively easy to care for once you take into account their special filter needs and their desire for hiding places, and their omnivore diet is a breeze.
Unhappily, they are on the menu for a lot of other fish, so finding safe tank mates might be a challenge, especially if you plan to breed them. With a little work, some attention to detail, and investment in a good magnifying glass, these charming shrimp make a great addition to any freshwater aquarium.