Beginners' Frequently Asked Questions


Mustafa Ucozler

1. Are shrimp aggressive?

Dwarf shrimp are absolutely peaceful and can be kept together in colonies.  Macros can be aggressive towards each other and other species of shrimp and fish. Many are predatory or opportunistic and will maim or eat dwarf shrimp if they get a hold of them.


2. How do shrimp reproduce?

Shrimp reproduce via eggs.  Eggs are produced in the ovaries of the female, which may or may not show up (depending on coloration of species) as a light or dark patch right behind the head area of the female.  After the female molts, the male mates with the female (facing each other) depositing his sperm at the opening of the female genital opening. Shortly after,  the eggs migrate from the female's ovaries through her genital opening to the abdomen.  As the eggs pass through the female genital opening, they are fertilized by the sperm that had been deposited there by the male earlier.  The eggs rest in the pleopod ("swimmerettes", swimming legs) area of the female. She carries them around wherever she goes. Depending on species, it may take anywhere between 2 weeks to 2 months for the young to hatch. Most dwarf shrimp species take 3-4 weeks to hatch. The hatchlings are tiny, barely visible and only a few millimeters long. Some shrimp species produce fully developed young, whereas others produce free-floating larvae that usually need a special saltwater/brackish water setup to be reared to the postlarval (i.e. benthic mini-shrimp) stage, at which point they can be acclimated to freshwater.  Time until hatching depends on temperature.  The higher the temperature (within reason of course) the shorter the time until hatching.  The young hatch directly from among the pleopods. The female does not deposit the eggs anywhere.


3. Do shrimp eat their young?

Dwarf shrimp do not eat their young and their young can be raised in the same tank.  Macros do not actively chase down their young but will display aggression toward their young over time which can stress out and kill the young.  Macros are opportunistic hunters so they will eat any small shrimp, including their own young, if the opportunity arises. With lots of cover many young macros will survive in the same tank as their parents, but it's best to raise young macros in a separate tank from the adults. Palaemonid shrimp with larval stages, inluding many macros and shrimp sold as "glass" or "ghost" shrimp, will actively hunt down and eat the larvae once the larvae get close to the ground or the sides of the tank.  It's best to rear the larvae of such shrimp in separate tanks.


4. What do shrimp eat?

Shrimp are omnivorous creatures.  They will eat anything that's edible. Both macros and dwarf shrimp can be fed on a diet of fish food and old, brown tree leaf litter that has been conditioned by bacteria and fungi in the tank.  The best food for filter shrimp are the micro-organisms that are blown out of the output of a well-established canister filter. A large enough hang-on power filter might work, too. The filter shrimp can actually live on the micro-organisms exclusively as long as your tank is large enough and has other shrimp or small fish that are fed every day.  This daily feeding keeps the micro-organisms in the filter reproducing, which in turn feeds the filter shrimp.  If you do not have a well-established canister filter (or maybe even a power filter if large enough) yet, *and* you see your filter shrimp sweeping the ground with their appendages, then you can offer them a few flakes. As long as the filter shrimp are filtering and producing droppings you can be assured that they are getting enough food. Some people grind up/powderize some flake food and offer this to their filter shrimp, but this can get messy if not done in extreme minute amounts and pollute the tank. Plus, you'll be feeding other animals, such as snails, at the same time, which is usually undesirable.


5. How much should I feed my shrimp?

You should only feed enough food that can be consumed within 5-10 minutes at the most. Never leave food in the tank for several hours and/or overnight. Overfeeding, and the resulting water parameter problems,  is one of the main causes for "sudden" shrimp deaths, which can wipe out your entire population. 


6. How do I distinguish between males and females?

With dwarf shrimp sexually mature males are slimmer, more streamlined and their abdominal area does not extend down beyond the pleopods.  Sexually mature females are plumper, look larger and their abdominal area extends down beyond the pleopods to accommodate eggs.  Also, females have a dark or bright patch in the area right behind their heads, also colloquially called "saddle."  These are eggs developing in the ovaries of the females. Sexually mature macro males tend to have much larger and/or longer chelae (=claws) than the females, which tend to have relatively small ones.  Also, macro males tend to get larger than females. The other gender distinguishing characteristics described above for dwarf shrimp apply to macros, too.


7. How large do shrimp get?

Dwarf shrimp tend to stay small in most cases, anywhere between 1.5 to 3.5 cm in most cases. Some species, such as the Amano shrimp can reach over 4 cm.  Filter shrimp range anywhere from 3-3.5 cm for dwarf species, to more than 15 cm for the largest filter shrimp species. Macros range anywhere from slightly under 5 cm to 30 cm or larger.  These sizes do not include the length of the claws for the macros. Most aquarium suitable shrimp are in then 1.5 cm to 10 cm range.


8. What tank size is appropriate for keeping shrimp?

The bigger the better. Shrimp need good water parameters to thrive.  The larger the tank, the less it is susceptible to worsening water parameters. A minimum size tank of 10 gallons is recommended. The larger the shrimp species and/or your population, the more space the shrimp should get.


9. Do shrimp need plants?

Shrimp do not need plants.  In fact, many shrimp come from habitats where are no plants at all.  Plants can actually adversely affect a shrimp tank.  Especially fast growing plants compete with microorganisms for nutrients and light (i.e. they shade them out) and also compete with filter bacteria, eliminating them in the worst case scenario. A plantless tank with leaf litter on the bottom  is best for shrimp. If you absolutely must use plants, use extremely slow growers such as java fern.


10. Can I fertilize my shrimp tank?

Fertilization of a shrimp tank is not recommended.  As mentioned above, shrimp need very clean water and good, stable water parameters.  Fertilizers can build up in a tank and cause "sudden" mass deaths.  Although you might be successful keeping shrimp for a short to intermediate time in a fertilized tank, there will likely be problems in the long run. 


11. Can I keep fish with shrimp?

Fish are not recommended in shrimp tanks for various reasons.  With dwarf shrimp the major reason is that almost all fish will either eat or bother the adults.  Although there are a few exceptions, almost ALL fish will eat shrimp hatchlings.  It does not matter how small your fish is and how small its mouth,  it *will* eat a shrimp hatchling when it gets the chance. Even if you keep a compatible fish, such as Otocinclus or certain plecos, with shrimp, the disadvantage is that fish tend to produce a lot more waste than shrimp, which can deteriorate water parameters (i.e. lots of nitrate).  This is especially the case in smaller tanks. With macros the roles are reversed. Most macros will harm peaceful fish if they have the opportunity.  Most of the time the fish are not hunted down but the macro literally runs into a fish and instinctively grabs it. This usually happens at night when fish sleep on the ground.  Most cichlids, however, are natural shrimp hunters and even a cichlid the same size of as the Macro can maim and kill the shrimp.  For all the above reasons shrimp are best kept in shrimp only tanks.


12. My male dwarf shrimp is riding on my female. Are they mating?

No, they are not mating. This seems to be part of their mating ritual and can be regarded as "foreplay."  For a more detailed description on how shrimp mate, see No. 2 of this FAQ.


13. What shrimp variety should I get as a beginner?

Most species of Necoaridina, such as red cherry shrimp, snowball shrimp etc., are recommended as "first shrimp."  The red cherry shrimp is usually the most available of all Neocaridinas.  These shrimp are very adaptable and can be kept in the tap water of virtually all parts of the US (and probably the world) as long as the water has been dechlorinated and the tank cycled.  If kept under the right conditions these shrimp will readily reproduce.  Although many first time shrimp buyers do not necessarily think of reproduction as an important aspect of shrimp keeping, seeing young shrimp hatchling grow to be adults can be a very rewarding experience.  Plus, your population will keep itself going virtually indefinitely if they are reproducing so you do not have to go out and constantly purchase shrimp.  Amano shrimp are very hardy and adaptable, too, but reproduction is much more difficult as Amano shrimp produce larvae that need to be reared in saltwater/brackish water.