Ghost shrimp (Palaemonetes paludosus) also have alternative names such as Glass shrimp, Grass Shrimp, and American Freshwater Glass Shrimp. Initially, they were found in North America. Nowadays, besides its popularity in shrimp breeding hobby, they are also sold as cheap food for larger fish species.
Ghost shrimp will be an excellent addition to the aquarium. They are amazingly hardy and can survive under conditions significantly better, compared to most other types of shrimp.
In addition, they are not shy. You will see them crawling around the entire aquarium in search of food, not hiding in the daytime, like most other shrimp. All in all, Ghost shrimp is one of the best options if you just want to get into this hobby.
Ghost shrimp. Lookalikes
Frankly saying, it is hard to find much reliable info on “Ghost shrimp” because many different species seem to come to be commonly referred to as “Ghost” shrimp, mistakenly or not. There is a lot of confusion around the name of this shrimp.
The point is that Ghost shrimp is a collective name. It includes lots of other shrimp species in the Palaemonetes genus. As a result, we have chaos in names. Also, to make it even more confusing, there are sub-genuses like Palaemonetes sinensis (Far Eastern Freshwater Shrimp), Palaemonetes Varians (Atlantic Ditch shrimp), Palaemonetes Argentines (Argentinean shrimp), Palaemonetes Antennarius (Popcorn shrimp), Palaemonetes kadiakensis (the Mississippi grass shrimp). All of them look very similar to ghost shrimp.
In addition, it can be hard to distinguish Macrobrachium and Palaemonidae family. For example, instead of American Ghost shrimp (Palaemonetes) you can get other types like Macrobrachium ehemals (Indian Ghost shrimp), Macrobrachium Lanchesteri (Thailand Ghost shrimp), Freshwater river shrimp and even somebrackish water variations.
The problem with all these shrimp is that they can also look the same to the untrained eye. That is why, consider yourself lucky, if you get by mistake, let’s say, a rather peaceful version of Ghost shrimp (Macrobrachium ehemals). Because, for example, Macrobrachium Lanchesteri are much more aggressive than other species. They can easily hunt down dwarf shrimp (like adult Red cherry shrimp), small fish and snails.
Quick Notes about Ghost shrimp
(Glass Shrimp, Grass Shrimp)
|Scientific Name||Palaemonetes paludosus|
|Tank size (optimal)||10 gallons (~40 liters)|
|Breeding||Medium-Difficult (a low order shrimp).|
|Size||3 – 5 cm (~1 – 2 inches)|
|Temperature||20 – 27C (~65°F – 80°F)|
|Optimal PH||7.0 – 7.4 (6.5 to 8.0)|
|Optimal GH||5 – 8 (3 – 15)|
|Optimal KH||5 – 8 (3 – 12)|
|TDS (optimal)||150 – 200 (100 – 400)|
|Nitrate||Less than 20 ppm|
|Life span||1 – 3 years|
|Color Form||Transparent, Orange, Yellow|
Note: Sometime ago biologists believed that Ghost shrimp belonged to the Caridina species. At some point, they revised it. Now as you can see they do not even share the same family.
Description and Appearance of Ghost shrimp
Ghost shrimp received its name because they have a semi-transparent body. Depending on the diet, the shrimp may become yellow, orange, beige or light-brown. The pigment granules in the body give Ghost shrimp the additional ability to camouflage against its background and blend in with the environment. Sometimes it can be hard to see them (although they could be right in front of your eyes) until they start moving.
They have a well-developed “horn” (rostrum) with small teeth along the dorsal and ventral surfaces, no claws on the third pair of walking legs. The tail of the shrimp has small specks. On the first 4 pairs of legs, there are tiny claws that help to collect food from the soil. They are rarely larger than 2″ in size.
Difference Machrobrachium Ghost shrimp vs Palaemonidae Ghost shrimp
Machro means “long”, and brachium means “arm”.
|Machrobrachium Ghost shrimp||American Ghost shrimp|
|Longer front legs|
|Larger front claws
(almost as long as the body)
|Their claws are much smaller|
|Many will develop a darker color.|
|2 small red dots on the tail.|
|Do not have the red color.||Red to orange bands in the legs and feelers.|
|Often develop faint patterning on their bodies like vertical bars.|
|Larger (~3 inches or 7.5 cm)||Smaller (~2 inches or 5-6cm)|
High Death Rate of Ghost Shrimp
It may sound strange, especially after my words that they are hardy and can be hard to kill. But let me explain it.
The main reason why the death rate can be high is because of poor care when these shrimp were captured and brought to the big brand pet stores. The thing is that they are usually considered as fish food. So, nobody sees any reason to care for “gonners”. As a result, these shrimp live under constant stress and without proper food. That stress over time is what is going to kill them. Yes, you can start taking good care of them but (because of that stress from a while back) the damage is already done.
Tip: If you are about to buy Ghost shrimp, pay attention to their color and activity. Healthy shrimp are almost transparent and hyperdynamic. If they have milky color and lethargic behavior, it means that the water conditions and (or) transportation were unsuitable and very stressful to them. So, if you decide to buy them, be ready for possible quick die-off for some of them if not all.
Practice shows that if you buy 10-20 of them, you will have at least 4-10 of them survive. Actually, this is a surprising number considering the treatment. You need to acclimate any shrimp before putting them in the tank.
The Diet of Ghost shrimp
Ghost shrimp are not picky eaters. On the contrary, you can call them very enthusiastic eaters. In the tank, they will eat everything that can find on the bottom, algae, tender leaves of plants, remains of fish feed, as well as detritus (dead leaves, waste).
The Ghost Shrimp is a somewhat decent scavenger and will go after all shrimp or fish foods placed into the tank.
When I was looking for information about this shrimp, I found in multiple articles (guides, care sheets) that Ghost shrimp are not an effective algae eater. Well, I prefer to check everything, so I started digging deeper and I found that it is not completely so.
Algae and Ghost shrimp
There was a study about Palaemonetes paludosus. The biologists opened up around 300 stomachs of the ghost shrimp and calculated their diet. I quote “Food of grass shrimp consisted primarily of algae, vascular plants, detritus, and aquatic insects. Algae was the major food item comprising 47% of total food ingested and occurring in 83% of the stomachs. Insects contributed least to the diet, comprising 15,2% of food ingested and occurring in only 36.2% of the stomachs”. (*Life History and Ecology of the Freshwater Caridean Shrimp, Palaemonetes paludosus (Gibbes). J. Thomas Beck and Bruce C. Cowell/ The American Midland Naturalist Vol. 96, No. 1 (Jul., 1976), pp. 52-65 (14 pages)
As we can see, the results of the experiment are completely different. Of course, they are no match to Amano shrimp. Nonetheless, Ghost shrimp do it algae. Unfortunately, biologist did not mention what kind of algae is their prime food source.
The Behavior and Aggression of Ghost shrimp
In the wild, Ghost shrimp live mostly in freshwater. Although, sometimes they can be found even in slightly brackish water. By nature, because of predators, they prefer a nocturnal lifestyle. At the same time, in the absence of big predatory fish, they do not remain hidden among the vegetation and you can see them everywhere anytime. Even compared to Amano shrimp they are bolder and completely ignore fish of their size.
Many articles about ghost shrimp say that the American Ghost Shrimp are usually non-aggressive. However, there have been systematic reports that some of them can become a bit aggressive.
First of all, they are very opportunistic and can eat baby shrimp of any species or even fish fry. In addition, they are hyper-aggressive to each other during feeding. They wildly try to get all the food for themselves and there is definite violence with their appendages.
Sometimes ghost shrimp can be territorial and fight everybody on their way if the tank is too small and there are too many of them.
Note: It is very interesting, ghost shrimp can fight over food between themselves. They can tear apart a worm but I have never seen them damage each other.
Gender difference of Ghost shrimp
When they are young it is hard to determine. The adults of the female and male sex are easier to distinguish.
1. The females of the ghost shrimp have a greenish saddle on the back that runs along the underside of their belly while males do not. The eggs underbellies also look like glowing green dots.
2. They differ according to the convexity of the back. The females have the pronounced curved arc along the top end of the tail.
3. The size of the shrimp. The females are much larger and thicker in the abdomen than the males. The length of the adult female is usually 5 cm, while the males are less than 4 cm. Note: according to the study, I quote “Females greatly outnumbered males in the larger size classes, and males comprised only 6.7% of the shrimp larger than 30mm”.
Unfortunately, ghost shrimp usually do not have any body markings, like Amano shrimp. Thereby, common methods of distinguishing shrimp gender work only up to some point with ghost shrimp.
Life Span of Ghost shrimp
Ghost shrimp are meant to be kept as a feeder fish (“Those who are about to die salute you, Caesar!”). That is why they do not live very long. Due to conditions, they are in when they arrive at the store.
Under good conditions, they can live up to 3 years in the aquarium.
Keeping Ghost Shrimp
A set up similar to a cherry shrimp tank should do fine for them.
Actually, it is quite easy to keep Ghost Shrimp. They prefer water at a temperature of 20 – 27 ° C, with parameters kH 3 – 12 and pH 6.5 – 8. However, they will also feel great in water with parameters that are different from optimal. Provide them with basic shelter, plants and they will be doing OK. They are excellent to be kept in both soft and hard water. Apparently, it does not matter much for them.
The only problem is the size of the aquarium. Females can sometimes grow up to 60 mm. Therefore, small aquariums (less than 5 gallons – 20 liters) are not suitable for them. Growth to maturity (20 mm) takes about 2-3 months when water temperature exceeded 26C (and 4-5 months when the temperature is lower).
In nature, their food menu consisted primarily of algae, vascular plants, detritus, and aquatic insects, in decreasing order of importance.
Tip: Keep in mind and remember that stability of water parameters can play even more important role in shrimp breeding (keeping) hobby than making them optimal.
Sex Ratio of Ghost Shrimp
According to the study, the sex ratio of 24854 specimens collected between May and April was one female to 0,78 male (P<0.05). Females were abundant in all months of the year. This is especially evident in the summer. Unlike other shrimp, the ideal ratio for ghost shrimp is 1:1.
Breeding Ghost shrimp
Brackish water confusion
There is a common misunderstanding that the Ghost shrimp need brackish water in order to breed. I would like to start off by saying that Ghost shrimp do not require brackish water in order to breed. It is a predominantly a freshwater species. In the laboratory experiments, Adult Ghost shrimp could survive at a salinity of 30 ppt (parts per 1000).
Also, there was conclusive evidence that egg hatching and larvae development proceed similarly in 5ppt and 0ppt.
After that (salinity of 10-20 ppt), the survival rate of the eggs drop significantly. The Eggs of ghost shrimp may not have the same osmoregulatory mechanisms as later forms in which tissues are more differentiated.
At the same time, results of the test on larvae indicated that short-term salinity tolerance was as high as that of adults, and that larva could even metamorphose in salinity up to 30ppt. Unlike the closely related freshwater Palaemonetes kadiakensis. The shorter larval duration may enable Palaemonetes paludosus to reach metamorphosis in higher salinities before dangerous effects are experienced by larvae.
The Mating Process of Ghost Shrimp
Basically, the breeding process is almost the same as with any dwarf shrimp. When the female is ready to breed, she molts. After that, her pheromones make the males start searching for her. They will fertilize the eggs outside of the body. After that, the semen will be held under her abdomen on her ovaries where the eggs will begin to develop.
You do not need any special conditions for breeding Ghost shrimp. It is absolutely possible to breed them in one aquarium.
Note: I will repeat once again that adult ghost shrimp can eat larvae or small shrimplets. That is why the second tank is advisable.
Tip: If you do not want to mess with the second tank but want to breed ghost shrimp, it is crucial to provide lots of plants and other small hiding places in the aquarium for the shrimplets. It will increase their survival chances.
Nonetheless, if you want to be a successful Ghost shrimp breeder, then the females with caviar should be placed in the separate tank.
Preparing Larvae Rearing Tank for Ghost Shrimp
The good thing about the breeding tank is that it can be without any filtration at all if you have a lot of plants there. There is almost zero bioload from the larvae.
A very slow running air stone would assist to distribute greenwater in the aquarium. The water movement should not be too strong. Otherwise, larvae will get blown around, so keep it very low and gentle.
What is different?
Their eggs hatch as free-floating larvae, not miniature versions of the ghost shrimp. At this stage, they are too small to catch. That is why it is better to move the female while she is still carrying the eggs.
After the appearance of the young, for the safety sake, put the females back to the main tank.
Ghost shrimp larvae are a little more difficult to raise because of the food requirements. Otherwise, the larvae will apparently starve and die if not properly fed.
How many Eggs do Ghost Shrimp usually have?
Ghost shrimp females fecundity ranges from 8-85 eggs and increases with the length of the female. The incubation period in the laboratory conditions was 12-14 days at 26-28C.
Average brood size – 35.9 eggs.
Maturity Size of the Ghost Shrimp
Biologist noticed that all immature females – 12-19 mm long. No females under 20mm carried eggs.
There are two stages of pre-hatching development:
1. An early stage where eye pigment was absent
2. Later stages where eye pigment was present (5 days after the eggs were laid)
Many females carrying eggs also had ripe ovaries.
Tip: If you see that the eggs are nearly at the bottom of the swimmeret, they are going to fall off anytime soon.
Hatching of Ghost shrimp larvae
Once hatched they hang under the surface for a few days as they cannot control their movements right away.
In the larval stage, they will require powdered food (Spirulina is a great algae for this), infusoria, Artemia, and zooplankton. Mix the powdered food thoroughly with water and then feed it like the cultured kind. Thus, having an abundance of water born algae would likely be highly beneficial for their survival.
Tip: Feed them twice a day ~50-100 ml. Use a syringe, it is very convenient.
The larvae will metamorphosis to miniature versions of the adults in about 5-10 days depending on temperatures. Big black eyes and sharply bent backs are the most obvious features at this stage.
Once the larvae have reached metamorphosis, they start swimming and act just like the adults. After that, they will require no further special care. They will molt frequently. You can do small water changes 5-10% every 10-14 days. Do not forget to cover intake.
Tip: if you have a filter in rearing tank, cover your filters water intake with a sponge or a piece of nylon stocking if you have not done it already. Most filters suck the water in to clean it. They can easily suck in larvae or tiny shrimp and kill it.
Interesting fact: According to another research*. The larvae were reared at room temperatures which varied from 15-31C (59-88F) during the course of the study. The tolerance level is amazing! (*The Larval Development of Palaemonetes paludosus (Gibbes, 1850) (Decapoda, Palaemonidae), Reared in the Laboratory. Sheldon Dobki. Crustaceana. Vol. 6, No. 1 (Aug., 1963), pp. 41-61 (21 pages)
Metamorphosis stages of Ghost shrimp larvae
The size of the larvae 3.7-3.9 mm. The rostrum is straight with dorsal hump near its base, and usually lacks spines. The carapace and abdomen lack spines. The abdomen has six segments; the last is fused with telson (tail). The eyes are sessile. The larvae have a yellowish ground color and numerous orange-red pigments mainly at the base of the appendages. The antennule is uniramous. Uniramous pleopod is non-functional. The first zoea generally molted within 24 hours of being hatched.
2. Second Zoea Stage
The size of the larvae 3.8-4.1 mm. The main difference between 1st and 2nd stage are the separation of the eyes from the carapace and the appearance of the last 3 pairs of pereiopods. In addition, the rostrum has a single dorsal spine. The second zoea generally molted after being in that stage for 2 days.
3. Third Zoea Stage
The size of the larvae 3.8-4.4 mm. The main difference of this stage is the appearance of uropods. In addition, the rostrum has acquired a second dorsal spine. The duration of the 3rd stage was 1 to 4 days depending on the temperature. However, molting occurred most frequently after 2 days.
Tank mates for Ghost shrimp
The rule is just the same. Do not keep them with any fish which can fit the shrimp in its mouth.
Ideally, ghost shrimp would be better to keep in a species only tank. Although, a peaceful community should work just fine. Just do not forget that ghost shrimp can be slightly more aggressive than other dwarf shrimp, especially during feeding time.
That is why it is better to keep Ghost shrimp with similar to their size species, such as the Amano Shrimp or Bamboo Shrimp.
In general, Ghost shrimp (Palaemonetes paludosus) are very interesting to watch shrimp. Lots of shrimp breeders noted that they have more “personality” compared to Neocaridina and Caridina shrimp. They are dirty cheap, easy to keep and hardy. You simply cannot ask for more! Ghost shrimp can be one of the best candidates as test subjects for anybody new to this hobby.
Some frequently asked questions about Ghost shrimp.
What Substrate do Ghost Shrimp Need?
They can live everywhere. However, sand, small gravel etc can make them happier. In nature, these shrimp can even build burrow to feed. They use the claws of the first and second legs to dig with and legs to draw the sandy mud backward. However, these burrows are not permanent and they do not stay close to them all the time.
Do Ghost shrimp need Brackish Water?
No, they do not need brackish water to live and breed. They can survive in brackish water, but it is not the same. The eggs of Ghost shrimp cannot develop in 10-20ppt salinity.
Ghost Shrimp becomes Whitish (or Pink)
There are two explanations here:
1. Good one. They change color when molting. When they are about to molt they will turn opaque but it will not be white.
2. Bad one.
– If they turn opaque and do not move. The molting was unsuccessful. The shrimp stuck in its exoskeleton.
– If they are white/pink for some time, most likely, they are sick and usually die.
– It is a reaction to the stress. Check your water parameters and look for possible predators like dragonfly nymphs.
Do Ghost Shrimp eat Cherry shrimp?
It is a very controversial subject. Many shrimp breeders saw Ghost shrimp attack and eat other shrimp. I am not talking about aggressive species like Macrobrachium Lanchesteri. Some people claim that even Palaemontes paludosus are capable to do that.
Palaemontes paludosus has very small claws which are not meant for hunting down prey. Nonetheless, it does not mean that they cannot catch a sick or dying animal and eat it.
Do Ghost Shrimp eat Snails?
I have already answered this question here (just scroll down to the bottom). However, considering the fact that Ghost shrimp are bigger than most dwarf shrimp and more aggressive, I would say that it is possible. They can eat including snails that cannot seal themselves in their shells. Sometimes even trapdoors are not enough to stop the ghost shrimp.
Are Ghost Shrimp Plants Safe?
Ghost shrimp are plants safe. However, if they start picking live plants, it indicates that the ghost shrimp do not have enough food. They will not eat plants unless they are really hungry.
That is the main reason why people report that they actually saw them eating the tips of leaves. It usually shows how hungry they are. In the wild, they can eat a small amount of live vascular plants from time to time. In general, the most part would usually be in the form of detritus (dead plant pieces) anyway.
How many ghost shrimp per gallon?
Practice shows us that 1-3 ghost shrimp per gallon is an optimal number. if you do not have anything else in your aquarium. Do not overstock the tank. It stresses shrimp (fish) and makes them aggressive.