When we think of aquatic pets, we usually envisage colourful tropical fish swimming in their glass enclosures. Rarely do we imagine shrimp crawling around in there. In the past three or four years, crystal-red shrimp have been gaining popularity in Hong Kong as pets rather than for the cooking pot, and they usually cost more money, time and patience than other aquarium varieties to keep or breed successfully. 'Lots of people love crystal-red shrimp due to their size. Breeding this little creature of only two to three centimetres takes up very little space. You know Hong Kong people usually live in small houses so it is suitable for them to keep crystal shrimp,' says Jackie Poon, owner of Crystal Garden pet shop in Mong Kok that specialise in the species. Crystal shrimp is the same species as another aquatic pet, the bee shrimp, only the colour being different - bee shrimp have black stripes and crystal shrimp red ones. Crystal shrimp are said to have originated from a Japanese bee shrimp breeder who found three red-striped variants among his stock, so he bred these and selected the darker red shrimp to breed again. Some pet shop owners in Hong Kong breed crystal shrimp themselves, while others import them from Japan. 'Some shopkeepers also bring in shrimp from Taiwan, but the quality is not as good as those from Japan,' Poon adds. The price of a crystal shrimp varies from HK$100 to more than HK$20,000. 'The higher prices are due to their appearance,' Poon says. 'Shrimp with beautiful patterns and those displaying neat stripes are more eye-catching [and therefore cost more].' According to Poon, crystal shrimp are sensitive, so they need more attention paid to them than other aquatic pets. They need their own aquariums as other fish may eat them. Aquariums must also contain purified water with no ammonia which can kill the shrimp. You also need to make sure the chloride level is not too high. The better the water, the longer the shrimp will live. 'Crystal shrimp live up to two years, depending on the condition of an aquarium and food. Conditions include the right amount of carbonate concentration, and calcium and magnesium concentration,' Poon says. The amount of chemicals determines shrimps' growth, and life-expectancy. Water temperature plays an essential part in their well-being. Ideally, shrimp should be put in water between 24-26 degree celsius - they can tolerate up to 28 degree celsius, but only strong specimens can survive at this temperature. When they do not eat or are too still, it is a sign the water needs to be checked. Vegetables are the main source of nutrition and owners can put moss into the aquarium. Crystal shrimp moult as they grow, but there is no need to remove the shells as the shrimp will eat them because they are a source of calcium. For owners, the most exhilarating part of keeping these tiny creatures is breeding. 'Even amateurs can breed crystal shrimp, providing the condition in the tank is stable enough for shrimps to reproduce,' Poon says. To help breed crystal shrimp, plants are indispensible as they are sources of nutrition and shelter. But plants and water weeds are also kept for aesthetic purposes too and looking after them can be more difficult than nurturing shrimp. 'More effort is needed if people want to have a tank with beautiful plants,' says Gary Kwok, an amateur aquatic plant lover. 'The most difficult part is to maintain an aquarium with an artistic sense. The way you arrange aquatic plants affects people's impression of it.' Willow moss is often used by aquatic plant lovers, Kwok says. The moss, commonly known as green carpet, is the most popular waterweed. Hongkongers usually go to Goldfish Market in Mong Kok and seek information from shop owners. 'The best way to keep aquatic pets is to do research before purchasing anything and be alert when buying tools or creatures,' Kwok adds.