An introduction to Shrimp

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Shelled inhabitants have been ever-growing in aquarium popularity. Gabor Horvath looks at the keeping and care of these leggy crustaceans.

Although they both live underwater, shrimp are very different to fish. Dwarf shrimp have a short lifespan (up to two years), for example, making them ill-suited to those who cope poorly with deaths. Worse still, shrimps can and will die for seemingly no reason at all. 

Before embarking on shrimp keeping, you must accept that despite your best care, fatalities still occur. Shrimp are particularly sensitive to certain chemicals, but even scent candles or air fresheners could cause troubles. Some imported aquarium plants are treated with insecticides — buprofezin, imidacloprid and trichlorfon — that are lethal to them. Nicotine from cigarette smoke. Flea spray. Even aquarium medications can kill them. 

Accumulated aquarium waste promotes bacterial infections. Regular gravel cleaning is a must, despite the shrimps’ reputations as cleaners. It’s advisable to remove shrimps during any substrate ‘deep-cleans, as thick substrates can accumulate toxic gases, which may kill the shrimp when released. Avoid substrates deeper than 2cm and add a couple of Malaysian trumpet snails to aerate them.

An empty shell can cause confusion.

Shelling out

One key culprit behind unexpected deaths is a failed moult. As shrimps grow, they shed their hard exoskeletons and then pump up their soft new shell underneath.
Old shells look like a dead shrimp, causing confusion for newcomers. 

The easy way to distinguish is that a corpse is never transparent, while a moult is never coloured. It takes time for the new ‘onesie’ to became hard and during that time the shrimp is sensitive to any external physical, biological or chemical contact. 

Colours are in the shrimp, not the shell. 

Moulting requires energy and is stressful for the shrimp, so it’s our task as keepers to provide them with the best environment to minimise risks — water with incorrect hardness, or low mineral and calcium content can hinder the formation of the new shell. 

Many fishkeepers forget this and concentrate on their Total Dissolved Solids (TDS) value instead. TDS is never steady, and it can increase, for example, through organic waste accumulation or the addition of salt. Both of these could result in an ostensibly ‘correct’ TDS, but neither is good for the shrimp. None of the dedicated breeders I know think that TDS is that important, many of them never even checking it. What they all agree is that GH and KH must be spot on. 

Blue bolt Taiwan bee shrimp. 

Ripe cherries

The most frequently encountered shrimp is the Cherry shrimp, Neocaridina davidi. The wild form is brown, but the common name refers to the first coloured variant bred in aquaria, which was the Red cherry. 

Since their introduction, aquarists have developed several colour forms, including yellow, blue, brown, black, orange or green ‘cherries’. The good news is that regardless of colour, every Neocaridina davidi requires similar water parameters. 

They are quite undemanding: keep them in neutral water of pH6.5-8, medium to hard at 8-18°H and 5-15°KH, with a temperature of 18-26°C, and you should have no problems. 

The best substrate for them is sand, and they love shifting through it in search for food. You can use ‘normal’ quartz sand, but my preferred choice is the JBL Sansibar Dark sand, which doesn’t compact like play sand does (leading to the build up of noxious gases), and the dark substrate enhances the shrimp’s colours. Avoid builders’ sand, as it may contain limestone that can alter water parameters. 

The bad news is that the different forms will all crossbreed with each other, so never keep multiple Neocaridina varieties together. If you do, expect some interesting (and usually commercially worthless) colours among the juveniles. 

I have a ‘skittles’ tank with some weird and wonderful cross-bred shrimp, but they will revert back to the original simple-looking, brownish shrimp after a few generations. 

Even when breeding Cherries of the same variety you will get plenty of off-colour spawns. If you want to keep your strains ‘pure’, remove the low-quality ones.

Painted red cherry shrimp.

Buzzing bees

A second shrimp group contains two Caridina staple species: the Bee shrimp, Caridina logemanni, and Tiger shrimp, Caridina mariae, as well as their numerous hybrids.
You may be familiar with the popular Crystal red shrimp and Crystal black shrimp varieties, and possibly the Taiwan bee shrimp varieties like King Kong and Panda. 

They’re relatively easy to recognise and identify, but even seasoned shrimp keepers can get lost among the recent Tibee (TigerXBee), TaiTibee (TibeeXTaiwan bee) forms, with new types appearing almost weekly with names such as ‘Galaxy fishbone’ or ‘BOA’. 

Some come with eyewatering price tags, touching the £2000 mark. Obviously, these are not aimed at beginners, but those on a tight budget could still find some beautiful (and hardier) Bee shrimp to keep. 

They’re a bit more demanding regarding water conditions than Neocaridina, preferring slightly cooler (18-23°C), softer (5°H, 0-2°KH) and more acidic (6-6.8pH) water, but they aren’t really difficult. 

To maintain these parameters, I advise specialist shrimp soils instead of sand, which help to stabilise the pH over a long period. Some of these active substrates may leach ammonia for a couple of weeks,
so make sure that the aquarium is thoroughly cycled before putting your shrimp in. I have JBL ProScape Shrimp soil in most of my tanks, as it doesn’t produce any ammonia, allowing me to repopulate my aquaria quickly. 

As opposed to the cherries, Caridina species do not revert back to a ‘wild’ form if crossed, so if you’re interested in creating interesting patterns and colours you could mix them. If you prefer uniformity, then just keep one variety in your tank.

 Blue dream shrimp

Other options

Other Caridina species are available infrequently, with varied popularity. One is the much-revered Amano shrimp, Caridina multidentata. 

Recent observations suggest that the ‘common’ Amano shrimps doing the rounds could be a mixture of several species. Even so, they remain strongly built algae-grazers and bottom-sweepers. 

As their care requirements are similar to many community fish, Amano shrimps are a perfect cleaner-crew for everyday tanks. 

The colourful Sulawesi shrimp species also belong to the Caridina genus, requiring relatively soft (6°H), yet alkaline (above 7.5pH) and very warm water. Because of these almost paradoxical needs, these shrimps aren’t recommended for novices but can be a great project for those wanting to try out something different. 

For well-established community aquaria you could also keep filter feeders, like the Bamboo shrimp, Atyopsis moluccensis, or the Armoured shrimp, Atya gabonensis. These scary-looking gentle giants catch microorganisms and particles of food from the currents with their fan-like appendages. 

You will often find them sitting on top of the internal filter, fishing in the flow. In a new tank or in aquariums without proper flow they may starve to death, so delay your purchase until there is enough food for them. You can keep these shrimps in a wide range of water conditions, just take care to avoid the extremities. 

Black orchid and Chocolate Neocaridina.

Setting up

Although some shrimp can be kept with certain fish, they fare (and breed) better in a dedicated shrimp tank. It doesn’t have to be large, and dwarf shrimp species are perfect for nano aquaria. Just as with fish, the bigger the tank you can offer, the more stable it will be. 

Once you’ve decided on a shrimp to keep, you can set up the aquarium, using the appropriate inert or active substrate. If your tapwater is low in nitrates and phosphates you could use it directly (after dechlorinating) in your Neocaridina shrimp tanks or mix it with RO water to soften it down and get the required parameters. 

For softwater Caridina species most keepers opt to use pure RO water and remineralise it with commercially available GH-boosting products. In some instances, baking soda (sodium bicarbonate) may need to be used to increase carbonate hardness as well. 

Decoration wise shrimps are not picky, as long as some shelter is provided where they can retreat to for moulting. When adding rocks avoid those containing lime. If in doubt use the acid test: drip some white vinegar (or better still a diluted hydrochloric acid solution) onto the rock. If it bubbles, it has lime, so don’t use it. You can use the same test for checking your sand substrate. 

Plants are also useful in the shrimp tank, but extra care is needed when purchasing them. Very often plants are treated with chemicals to remove pest snails, and the residue is more than capable of killing your shrimps. It can take weeks (or more) to soak out these pesticides, so the best bet is to buy plants from reliable sources with a pesticide-free guarantee. Plants from others’ shrimp tanks or tissue culture plants are the safest bets. 

After spending money on substrate and safe plants you will be glad to hear that — unless you want to keep Sulawesi shrimp — you won’t need a heater. Room temperature is perfectly fine for Caridina and Neocaridina species. 

I know lots of breeders who allow their tanks to cool down under 16°C during the winter months. It gives some rest period for the shrimp, which may stop breeding for a while, but will resume with extra vigour when spring warms up their water.

Neocaridina ‘Skittles’.

Specific disease

With their different physiology, shrimps are prone to different infections to shrimps, and the most common of these are Scutariella and Vorticella. Vorticella exhibits itself as fluffy growths, usually around the head and gill area of the shrimp, and is problematic if it grows abundantly, as it may clog the gills. Treatment is difficult, with a potassium permanganate solution looking to be one semi-reliable method.

Scutariella is a type of nematode flatworm that grows between the eyes of the shrimp, on and around the rostrum. In some cases, you will even see their eggs inside of the shrimp’s shell around the gills, as tiny white dots. A lot like Vorticella, they aren’t normally a problem unless high numbers are reached, whereby breathing may be impaired, but for the best part the worms are just hitching a ride. Treating them can be done with salt, No Planaria, Seachem Paraguard, or wormers like fenbendazole, though success rates fluctuate. 

The best approach in each case is just to buy carefully and avoid purchasing any shrimps with obvious whitish growths around the head. 

Skittles’ Neocaradina in detail.

The drip method

The safest way to introduce shrimps is with the drip method, especially if they were bought online and have been in transit for some time. 

After dimming the lights, transfer the contents of the shrimp bag into a suitable container — a small plastic tank or a bucket. Be careful not to disturb it too much, as this may release CO2 and increase the toxicity of any ammonia in the water. A single drop of Seachem Prime added to the shrimp water isn’t a bad idea to help detoxify any ammonia present. 

Use a length of airline with a clamp or flow controller to start a slow siphon from the aquarium into the container with the shrimp. Aim for 1-2 drops per second. Allow this dripping to occur for an hour or so until the volume of water in the container has tripled or quadrupled. 

Now use a shrimp-safe net (coarse nets can cause entanglement) to catch the shrimp and transfer them to the aquarium, before discarding the water and topping the aquarium back up with fresh, treated water.

Rules of acquisition

You definitely need a good filter.

My preference is for air-driven sponge filters, as these provide a perfect grazing ground for the young shrimplets, but if the bubbling noise is too disturbing an internal or external power filter would also suffice. You should cover the intake grill of the filter with a stocking to avoid baby shrimp getting into the filter. Alternatively you can use shrimp-safe products, like the Dennerle Nano corner-filter or the JBL Mattenfilter.

After properly cycling the tank it’s time to get your shrimp. Unfortunately, the selection available in most of the fish stores is very limited, so often your best option is searching the net. 

Before buying from anyone, join a couple of shrimp social media groups and ask members about their experiences with any particular seller. Remember that dodgy sites looking for quick profits by selling freshly imported, non-quarantined shrimp can disappear and appear under new names, so stick with the reliable, long standing ones, especially if they sell their own-bred shrimp. 

I usually acquire my Caridina shrimp from shrimpcorner.co.uk and the quality is always excellent. The other option to buy shrimp is to find local breeders, so you can see your shrimp in person before buying. 

Try to buy young shrimp, as they adapt much more easily. They may not look as stunning as fully matured adults, but will live much longer and you could have the satisfaction of watching them getting more and more beautiful daily. 

Feeding quality fares ensures the balanced diet required for moulting and breeding. I use Shrimp King, JBL and Hikari products, with blanched fresh leaves (stinging nettle, dandelion, spinach) and vegetables (courgettes, cucumber) as an addition. 

As I have relatively few shrimp per tank, I only feed them every other day, leaving the shrimp to graze on the biofilm growing on the decoration between meals. 

Shrimp babies

If kept well, shrimp begin breeding when they reach around six months in age. Females develop eggs, which can be easily visible as yellow ‘saddles’ on the back of some shrimp. When these ready-to-breed females moult they release pheromones, which will make all the males in the tank behave a little crazy. 

If you see your males swimming all around the tank you can expect to see a ‘berried’ shrimp carrying eggs under her tail soon. 

The spawn will hatch in about three weeks’ time and the developing shrimplets can be clearly seen within the eggs. The newly hatched babies of Neocaridina and many of the Caridina species are released fully formed and require no special care if there is enough biofilm in the tank. Alternatively, finely powdered Spirulina can be added to feed them as an initial food supply. 

True Amano shrimp and the filter feeders produce less-developed larvae which require saline conditions to survive, so breeding them in a tank is difficult. 

Shrimps can breed monthly, so in a well-kept tank you will soon have plenty of them. Just remember: don’t get too attached to an individual, as shrimps could die. Get attached to a species or two instead: hopefully the sight of the growing new generations will make it easier to accept the occasional losses and you will find joy in shrimp-keeping — just like I did.