Minimum Tank Size 10 Gallons (37 Liters)
Care Level: Difficult
Water Conditions: PH 5.8-7.4 Soft to Moderately Hard
Temperature: 71-77°F (22-25°C)
Maximum Size: 1.2 inches (3 cm)
The red crystal shrimp (Caridina cf. cantonesnsis var. Crystal Red Shrimp) is a popular and stunning freshwater dwarf shrimp, that is rapidly becoming one of the most popular shrimp in the hobby. These shrimp are actually a color variant of the humble and diverse bee shrimp. Originally selectively bred in Japan, they are still known as ‘red bee shrimp’ in parts of Asia.
While red crystal shrimp aren’t found in the wild, their ancestors were native to the Guangdong and Guangxi provinces of China, Hong Kong, and some reports indicate they are also found in Vietnam. Bee shrimp are primarily found in small mountain streams.
While there is significant demand for these shrimp in the hobby, nearly all the shrimp available for sale come from farms in Taiwan. Very few bee shrimp are collected from the wild, and color variants like red crystal shrimp are all captive bred – which has resulted in them being slightly more delicate than most other commonly available shrimp.
Red crystal shrimp have a relatively short lifespan, living on average around 18 months in a home aquarium. If they are well cared for, they may live up to two years, though this is rare.
Red crystal shrimp have slightly unusual requirements for an invertebrate, and for them to be truly healthy in an aquarium, they require soft and slightly acidic water. With that being said, they can adapt to a wide range of conditions, but breeding may not occur if they are kept outside of their preferred water parameters.
These shrimp have been selectively bred for numerous generations, and because of this intense inbreeding, they tend to be slightly more delicate than many other species of shrimp. They need a well established and stable aquarium, and due to their expense and fragility, it’s usually recommended to keep them in a species only tank.
Red crystal shrimp should never be kept in anything smaller than 10 gallons (37 litres), and they thrive in large, densely planted aquariums (CO2 supplementation should be avoided). Regular maintenance of the aquarium is essential, as these shrimp are very sensitive to nitrites. A weekly water change between 15-30% is recommended to keep the water in pristine condition. However, regular testing should be conducted on the water to identify any problems quickly.
If these shrimp are kept in a species only tank, then the best filter to use is a sponge filter. These filters are safe for hatchlings, and still provide excellent biological filtration. But, if these shrimp are kept in a community tank, then a hang-on-back filter is usually the best option. I personally recommend the Aquaclear Power Filter, and use this filter on the majority of my aquariums.
Care should be taken with the filter intake, to ensure no hatchlings are sucked up into the impeller. Some stores sell sponges to place over the filter intake, but I find non-toxic, homemade mesh to be the best option (make sure the material isn’t dyed).
Red crystal shrimp are filter feeders, and are also known to consume algae and vegetable matter. In the aquarium, they should be fed a high-quality sinking pellet, along with regular offerings of washed and blanched vegetables. One of the best foods you can feed them is Hikari Tropical Algae Wafers, which is an excellent sinking food for herbivores.
Because of their tiny size, they should only be offered small portions of vegetables, with any uneaten leftovers being removed within 24 hours. If the vegetables aren’t removed, they will foul the water. Some good vegetables to offer them are lightly blanched zucchini medallions, cucumber, shelled peas, broccoli, and romaine lettuce (avoid iceberg lettuce as it has very few nutrients).
These shrimp will breed readily in-home aquariums, and if both males and females are present, hatchlings will usually appear without any intervention from the aquarist.
When it comes to determining the sex of these shrimp, things become a little more difficult. Even to a trained eye, both the males and females look very similar. The best way to differentiate between the males and the females is to look at the size of the shrimp; The females are larger than the males with a deeper abdomen and wider tail.
Once the female is ready to mate, she will release pheromones in to the water. The male will then be seen swimming around the aquarium frantically, seeking the female.
After mating has occurred, the female will carry the eggs under her abdomen. She will use her pleopods to circulate water over the eggs. The eggs will usually hatch after 30 days, though the water temperature will influence the length of incubation. Ideally, the shrimp should be raised in water at the cooler end of their preferred temperature range. Not only will the hatchlings grow larger in cooler water, but will also have better survival rates, although their growth rate will be slowed.
Because red crystal shrimp hatch as fully formed shrimp and don’t have a larval stage as many other shrimp do, hatchling mortality is usually quite low. Unless they are bred in an aquarium containing fish, in which case, many hatchlings will be lost to predation.
In an aquarium with invertebrates, anything copper based must always be avoided. Many medications contain copper, so fish should always be treated in a separate tank from the dwarf shrimp.