Colourful centrepiece or expensive snack? The fish you house with your shrimp need to be carefully chosen if you want to avoid turning your tank into a living buffet, Nathan Hill investigates some of the options for your shrimp tank.
Looking back, my main pastime during lockdown may have been browsing aquatic forums. What struck me forcibly was that as shrimp keeping has increased in popularity. As has the number of people asking the simple question, ‘What fish can I keep with my Neocaridina cherry shrimps?’
Log in to any forum and ask that question, and I promise that you’ll find as many differing opinions as there are members.
To start, why would anyone want to add fish into a shrimp tank? I suspect that it’s mainly a question of aesthetics. Shrimp are, admittedly, rather small, and incredibly good at hiding. They can be expensive, and beginners tend to buy five to ten at a time, just in case things go wrong.
Getting a glimpse of a small shrimp picking at the substrate always excites hardcore shrimp fanatics. But not all of us are so hardcore, nor happy to settle for shrimps alone. Wanting some additional movement in the tank, or a visual focal point, is totally reasonable.
You could argue that a few colourful fish will benefit the aquarium. After all, shrimp don’t often make use of the mid-water spaces. Plus, if that helps people to enjoy their tanks, then that’s what the hobby is all about.
Many people feel every community fish tank needs a pleco. Similarly, some people feel that a shrimp tank is incomplete without a centrepiece fish. However, it is important to think carefully about the requirements of your shrimp before combining fish and shrimp.
Related article: Top 10 small fish for nano aquariums
Amano shrimps are bigger and more switched on.
Prior considerations
Shrimp generally like stable conditions: no large, sudden changes. If you keep fish, then the chances are that you often carry out large, frequent water changes. The shrimp will not enjoy these changes, and they can trigger premature moults and 'random' deaths.
Shrimp and fish do not always enjoy the same water parameters, so you may find you need to find a compromise. A recent trend in keeping hillstream loaches (usually Sewellia or Gastromyzon spp.) with shrimp is a typical example. The loaches’ love torrential conditions, whereas the shrimp cannot handle this fast flow.
Shrimp are also quite sensitive to pH, TDS and temperature. You will find it much easier to adjust these if they are the sole occupants of the tank. This also means you need to introduce shrimp to their new home slowly and carefully.
Even more dangerous to the entire colony can be the death of a fish or large snail. The devastation from a dead but well-hidden Tylomelania snail is something I cannot forget. I no longer deliberately keep snails with my shrimp because of this to ensure water quality remains optimal.
Sadly, the dwarf ramshorns missed that memo, so they continue to inhabit my tanks. It pays to be watchful as a mass pest snail die-off may be more difficult to spot but just as toxic as the death of a larger snail or fish.
Dead fish do not always have the good manners to die out in the open and can remain hidden. This can cause an ammonia spike that can easily wipe out your colony. Medicating fish in the case of illness is fraught with danger, as many medications are not invertebrate-safe. All the more reason to keep a spare hospital tank.
Eggs and shrimplets are high risk.
Feed or be fed
Many fish are natural predators of shrimp; housing the two together will likely mean they behave differently. Shrimp may hide more frequently and breed less frequently.
Freshwater shrimp can be slow to settle in to new tanks. However, if your shrimp are still hiding after a few weeks, it is possible that the fish are hunting them at night.
If you’re seeing ‘berried’ (pregnant) female shrimp but no babies, or you’re not getting berried females when your water parameters are perfect, then take a long, hard look at the other tank inhabitants.
Shrimp can miss out at feeding time. Fish are usually quicker to the food and less inclined to be scared off by a shrimp’s threat displays. Equally, fish that are shrimp-friendly tend to naturally compete for the best algae or biofilm.
Without their habitual diet, young shrimp are less likely to survive. Aquascapers may also wish to avoid keeping fish with their shrimp simply to avoid the damage that they can do to live plants.
Spiny eels love to snack on shrimps.
Who’s out?
All this before we even address the damage that live fish can do to shrimp! The problem is that fish will often eat anything that fits in their mouths. That’s largely true, but not always.
Many fish will indeed automatically hunt anything that is small enough for them to eat, but some won’t. Some fish are physically able to eat shrimp, still don’t appear to. Then there are those that will eat juvenile shrimp but not adults. So which fish are best to keep with shrimp?
First, we can dismiss any large fish and members of the cichlid family (and yes, that does include angelfish and discus). Even dwarf cichlids are hunting machines and they will quickly clear up any shrimp they can find. Amano shrimp (Caridina multidentata) are a staple of planted aquariums and may survive. But they will certainly have a sense to hide.
Many other aquarium fish don't belong with shrimp. These include goldfish, large rainbowfish, large gouramis, spiny eels, larger livebearers and most loaches.
With any of these, it is not a matter of if but when they will eat your shrimp. Personally, I would include the larger tetras and barbs into this group. Although, I am sure there will be hobbyists who have successfully kept them together.
Pseudomugil can possibly be tank mates with shrimp.
Who’s a maybe?
Then there are the fish that might or might not eat your shrimp.
These will almost certainly eat the young, but if you are not interested in breeding them then this could be a happy-medium. Nevertheless, it is worth giving your shrimp colony time to build up before you add the fish.
By including a plethora of hiding places and plants, and keeping the fish well-fed, you can reduce losses. Guppies, rasboras, small danios, kuhli loaches, pencilfish, clown killifish, and corys are just some of the options here.
White Cloud Mountain minnows and the small rainbowfish of the Pseudomugilidae are also good potential tankmates.
One fish in particular that people want to keep with their shrimp is the Siamese fighter, Betta splendens. Successfully keeping them with inverts appears to come down to individual ‘personality’ and a fair bit of chance.
I know people who have kept a betta that ignored shrimps entirely. Others have had whole colonies hunted down in a matter of days. The same applies to dwarf puffers (Carinotetraodon travancoricus); again, this is a gamble that may not pay off.
Related article: How to feed your new Betta splendens
Otocinclus are 100% safe
Shrimp safe fish
All things considered, which fish are completely safe to keep with shrimp of all sizes?
In the first instance, if it’s an algivore, then it won’t be interested in (or often even capable of) eating your shrimp. Sadly, these tend no to be the bright, colourful fish of people’s dreams.
Instead, they are rather drab and shy grazers that venture out to shuffle over plants or stones around the tank. Otocinclus and their close cousins Parotocinclus or Hypoptopoma are the principal candidates.
For something a little more exotic, look at zebra otos (Otocinclus cocama). Expect to pay considerably more than for a standard Otocinclus. If you have the space and want something more substantial, then thin but lengthy suckermouths like Farlowella could be the way forward.
For those in need of a flash of colour, have a look at the dwarf rasboras in the genus Boraras. This genus includes the popular chilli rasbora (B. brigittae).
These are visually punchy, peaceful, relatively cheap and small enough to live with shrimp in nano tanks. They have the added advantage of having tiny mouths. Any mortalities will be of the youngest baby shrimp.
Ultimately, the question isn’t “what fish can I keep with my shrimp?” but “should I keep fish with my shrimp?”. Of course, the decision is entirely up to you.
It can work well if you are simply interested in keeping adults, rather than breeding.
however, once you watch your male shrimp race around your tank to find a newly-moulted female releasing her pheromones. Then your berried female increasing in girth, until you can see the developing eyes in the eggs. I can guarantee that the last thing you will want is for your precious shrimplets to disappear.
With a little bit of patience a shrimp-only tank can swarm with active, exotic invertebrates, that rival any fish. Try it; your shrimp will thank you for it.
Crystal red bee shrimp.
Related article: An introduction to shrimp
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