Creature Companion - Interzoo Special September 2019 | Page 31

KEEPING CRAYFISH IN MOLTING IN AQUARIUMS CRAYFISHES Keeping crayfi shes in an aquarium is very easy. A single specimen can be kept in a 20 litre tank. A 50+ litre aquarium can house more than one crayfi sh. It is not advisable to keep fi shes as tank mates in such small aquariums. But in bigger tanks, fast moving fi shes can be kept with crayfi shes. Molting (ecdysis) is a process required for growth of crayfi shes and other members of Decapoda order. Th e crayfi sh must molt its external shell “exoskeleton” to increase in size. A young crayfi sh can molt upto 11 times to reach maturity. Molting also depends on diff erent factors like water quality, food quality and oxygen level. A crayfi sh can increase upto 15 percent in length and 25 to 40 percent in weight between every molt. Let’s see some Crayfi sh aquarium essentials: 1. Tank: Crayfi shes can be kept in small tanks, so a 5 gallon tank is enough to start with. Even 2 Crayfi shes can be kept in 15 gallon of water volume. As they can breed easily in suitable conditions, it is advisable to own a bigger tank. 2. Substrate: Crayfi shes are scavengers and so are always likely to disturb substrate in their search for food. Th ey can survive in a wide range of pH. So, keeping them with sand is a good idea. 3. Decoration: Crayfi shes like to climb and hide. Creating small creeks between rocks provide them ample hiding places. Some plants such as Anubias or Java ferns can be kept in crayfi sh aquariums. Fast growing plants like Hornwort also provide them with a natural source of food. Crayfi sh are also known to escape from the aquarium. Th ey can also escape by climbing on fi lter/heater wire and drift wood branches. So, caution must be exercised to close the tank housing crayfi shes properly. 4. Filtration: Crayfi shes like to live in clean water, free from pollutants and chlorine. Th ey are scavengers and always like to dig the substrate, which makes good fi ltration all the more essential. Crayfi shes require mild to medium high fl ow in water so care should be taken to choose fi ltration equipment with intermediate fl ow. 5. Light: Most of the crayfi shes like to hide and so, it is not advisable to use high light in crayfi sh tanks and aquariums. Keeping them in medium to low light is both comfortable and preferable. 6. Water Change Schedule: Clean water is the key to success for the survival of all aquatic pets. In a crayfi sh tank, water should be conditioned carefully before releasing into the tank. Any chemical pollutants such as chlorine, heavy metal ions etc should be removed. Th e temperature of water must be kept same to the aquarium temperature. Changing 30 to 40 percent of water once a week is enough. Th e molt or exoskeleton should not be removed from the tank. It serves as good feed for the crayfi shes. Th e exoskeleton completes the nutrient and mineral requirements of crayfi sh. Adding some Potassium iodide can be very benefi cial for crayfi sh. 7. Temperature: Most of the crayfi shes like cold water. Although some crayfi shes like to live in tropical environment and can happily survive in higher temperatures. Th e acceptable temperature range for crayfi shes is from 190° Celsius to 250° Celsius. 8. Food: In wild, Crayfi shes eat plants, decaying and dead animals. In aquariums, sinking fi sh food, shrimp pellets, vegetables, fruits can be provided as nutrition sources to Crayfi shes. Being omnivorous, they happily eat anything from vegetables and plants to fi sh food and live food. PRECAUTIONS WITH CRAYFISH TANK Some basic precautions to be taken with crayfi sh tanks are listed below: • Always remove excess food from the tank. Controlled feeding maintains the water quality. So, never off er too much food. • Keep away all heavy metals from the tank. Use fertilisers and algaecides carefully. Heavy dose of copper fertilisation can kill the invertebrates. • Ensure clean, chemical-free and pollutant-free water for the aquarium. • Crayfi shes are great escapers. Make sure to close all the holes in the aquarium from where they can possibly escape. Crayfi shes are one of the least maintenance pets. Watching their activities is very interesting and full of enjoyment. * Rajiv Sharma is the Founder of online aquarium forum www.aquapetz.com. He is also an aquarium hobbyist and planted aquarium designer. His email id and phone number are [email protected] and 9958075234. September 2019 • Vol. XII • Issue 9 • Noida 31 | Creature Companion