Palaemonetes paludosus, known as ghost shrimp, glass shrimp, and eastern grass shrimp, is a species of freshwater shrimp from the southeastern United States. They have been popular in home aquariums since being first described in 1850 with fish keepers of all experience levels.
There are a number of different species of ghost shrimp within the Palaemonetes genus, however, most fish stores just use the common name ‘Ghost Shrimp’. Nowadays they can be found across the world, though most populations are reared in farms as feeder fish or to supply home aquariums. While frequently used as bait by fishermen, wild populations can be problematic for the fishing industry; this is because they act as pests in aquaculture.
In an aquarium, ghost shrimp make your life that little bit easier. As a prominent scavenger, the shrimp will clear up any uneaten food as well as keeping algae levels down. Their cleaning prowess will keep the tank looking clean. They do this throughout the day and are always active and busy. Their behavior ranges from free-swimming and feeding/cleaning all around the tank.
A group is not necessary though, a single shrimp will function happily on its own. When getting the shrimp be sure to check whether they are bred as feeder fish or for a home aquarium. Feeder fish are often treated poorly and are unlikely to survive as long. As the name might suggest, ghost shrimp are mostly clear in color in order to evade predators. This allows the inner-workings of their body to be viewed as it processes food, a large reason as to why they are an attractive addition to an aquarium. Different specimens may have different colored dots on their backs. They will grow to roughly 1.5 inches but females will become larger than males.
Ghost shrimp have two pairs of antenna, one long and one short. These antennae are sensory organs that detect tactile or chemical information such as toxins or food in the water. Antennae also have social uses but this is less understood. The rostrum, a beak-like extension, is between the eyes and in front of the carapace. The carapace is a hard protective shell that encases the softer parts of the shrimp for defense. Behind the carapace are six flexible abdominal segments that house pairs of pleopods “swimming limbs”. The sixth abdominal segment connects to the tail, in the middle of which is the telson, the final segment. Under the telson are four further segments that embody the uropod, forming the iconic tail fan.
A freshwater shrimp like this one would typically live in rivers or lakes where there is flowing water, fine sediment, and crevices to hide in. It is important to consider this when designing your aquarium. Given their small size ghost shrimp can be kept in relatively small environments, 5 gallons should be treated as a bare minimum but preferably larger. You can safely keep around 3 or 4 ghost shrimp per gallon, though bear in mind the number of other species you have in the tank. Shrimp contribute to the biological load, but far less than most fish. If you are unsure then it is always better to start with fewer so that you do not risk overstocking the tank, you can then add more later. An ideal aquarium would contain an abundance of live plants. Some popular examples are hornwort, ambulia, and java moss.
Ghost shrimp will use debris from the plants as an additional food source, varying their diet and tidying your tank at the same time. However, make sure that the plants are hardy so that they can survive any nibbling from stray shrimp. Plants also provide areas for shrimp to hide in, particularly when molting but also when being harassed. Decorations and rocks can also be used to diversify the hiding spots available. As bottom-dwellers, ghost shrimp will spend a lot of their time on the sediment and are known to burrow. Sand or fine gravel reduces the likelihood of damage to the shrimp, and most importantly their sensitive antennae. A fine-grain prevents food from sinking into the sediment as well, meaning that it sits on the surface waiting for scavenging shrimp.
When considering the water parameters in the tank, ghost shrimp are not fussy. They happily suit standard tropical aquarium conditions. Temperatures can range between 65 and 82ºF. Some people claim that these boundaries can be stretched even wider, but this may stress the animals and reduce shrimp activity. The water should be slightly hard and kept between a pH of 7.0 and 8.0. Ghost shrimp enjoy a light flow of water which can easily be generated by the filter outlet or an air pump. Generally, the shrimp can cope with most conditions, provided that they remain consistent. Ammonia, nitrite, and nitrate levels need to be monitored, as well as any other potential pollutants. Overfeeding, overstocking and dirty filters are likely causes for levels to rise. Ammonia and nitrite are toxic to fish and should be kept as low as possible. Nitrate is less toxic and is used by plants for growth, but should be maintained around 5-10 ppm. Regular water changes will help to control these chemical levels. If you are keeping ghost shrimp as feeder fish then their tanks can be more simplistic, with a similar setup to a breeding tank (you can read more about this below). Just make sure the water is kept clean and moving.
Ghost shrimp are easy to feed as they will greedily eat anything you present them with. This includes most shop-bought foods such as flakes, pellets, and algae wafers. Their broad diet makes them excellent tank cleaners as they will consume excess algae, plant detritus, and any food left over from a fish’s meal. Watching a shrimp rise to the surface to grab a flake is particularly entertaining, but if you have a tall tank then sinking pellets will make it easier for them to grab some food before all of the mid-water fish take it. One algae pellet will easily fuel a tank containing many shrimp, any more and you risk overfeeding. The food mentioned should be sufficient to maintain a healthy shrimp, but calcium supplements could also be added to ensure a strong shell is formed. Take a look at the Aquapoda mineral blocks for this. It is important to note that copper is very toxic to shrimp and should not be introduced into the tank. When adding medication into the water be sure to check its contents, as many contain copper.
If ghost shrimp are kept in a healthy environment with no predators and limited stress then they are generally easy to breed. This is one reason why they are so commonly used as feeder fish. However, a breeding tank is needed in order to grow your population. Make sure that there are males and females in your main tank, females can be spotted once they’ve matured because they grow to be much larger than the males and develop a green saddle underneath their body. Every few weeks females should produce eggs, around 20-30 green dots attached to the female’s legs. When you see this, wait a few days so that the males have a chance to fertilize them. Then move the berried female (individuals bearing eggs) to the breeder tank before the eggs hatch, otherwise the young will become a food source for any other creatures around. When the eggs hatch in the breeder tank, move the female back to the main tank or she will be tempted to eat her own young. This should take about three weeks.
The breeder tank should have a sponge filter so that none of the young get sucked into the equipment. The rest of the tank should be similar to the main tank but it can be more minimalist. There should be a thin layer of sediment down but fewer hiding spaces are needed. A few plants are useful since they act as a food source for the young shrimp. Along with plant debris and any algae in the tank you should feed the larvae very small amounts of fine particle food, as they have tiny mouths.