OPEN COURSE AQ5 D01 ORNAMENTAL FISH CULTURE GENERAL INTRODUCTION An aquarium is a marvelous piece of nature in an enclosed space, gathering the attraction of every human being. It is an amazing window to the fascinating underwater world. The term ‘aquarium’is a derivative of two words in Latin, i.e aqua denoting ‘water’ and arium or orium indicating ‘compartment’. Philip Henry Gosse, an English naturalist, was the first person to actually use the word "aquarium", in 1854 in his book The Aquarium: An Unveiling of the Wonders of the Deep Sea. In this book, Gosse primarily discussed saltwater aquaria. Aquarium or ornamental fish keeping has grown from the status of a mere hobby to a global industry capable of generating international exchequer at considerable levels. History shows that Romans have kept aquaria (plural for ‘aquarium’) since 2500 B.C and Chinese in 1278-960 B.C. But they used aquaria primarily for rearing and fattening of food fishes. Chinese developed the art of selective breeding in carp and goldfish, probably the best known animal for an aquarium. Ancient Egyptians were probably the first to keep the fish for ornamental purpose. World’s first public aquarium was established in Regents Park in London in 1853. Earlier only coldwater fishes were kept as pets as there was no practical system of heating which is required for tropical freshwater fish. The invention of electricity opened a vast scope of development in aquarium keeping. The ease of quick transportation and facilities for carting in temperature controlled packaging has broadened the horizon for this hobby. Today, a person in cold water region can enjoy the beauty of tropical freshwater aquarium as well as the exotic marine coral reef aquarium. The modern facilities for ornamental fish breeding and culture and the easy availability of wide variety of aquarium equipments and fish feeds have greatly increased the number of aquarium hobbyists all over the world. Choosing a spot for an aquarium First, you will need to think about how much free space you have for your aquarium, whether that free space is open to sunlight, and which shape that is best suited for that free space. Never place an aquarium in direct sunlight and keep the aquarium away from heating or cooling surfaces. Sunlight and heating or cooling surfaces will cause sudden and drastic changes in the temperature within the aquarium, and sunlight will also promote the growth of algae in the water. Keep your aquarium away from machines that give out a lot of sound or cause vibration, like the washing machine, since this will stress the fish. Water accessibility and easy disposal of dirty water and waste are some other important factors to consider while selecting a good spot for your aquarium as you don’t want to run around with buckets of water in your entire house. One needs to clean and change water at least monthly and better once a week. So, choose a place where one can work easily and without any interference. In a family with children, special care has to be taken to keep the aquarium away from areas of frequent activity. - 1 - You should also consider that an aquarium is very heavy so the chosen spot has to be able to support the weight of the aquarium. Any aquarium over 10 gallons/ 40 L will weigh at least a hundred and fifty pounds / 70 Kg when filled and decorated. The weight comes chiefly from the glass and the water, and decoration such as gravel will further add to this weight. Heavy aquaria will need to be kept on a sturdy stand rather than a shelf or a desk. Choosing an aquarium Aquariums come in many shapes and sizes. For a beginner, the convenient size will be 60cm X 30cm X 30cm because too small an aquarium may not worth watching. It is advisable to choose an aquarium that is at least 10 gallons/ 40 L, (1 gallon is approximately equal to 4.5 litres) since small aquariums are much more difficult to maintain. The waste build up in small aquariums is quick and quite large in comparison with a larger aquarium. A small aquarium will therefore require very frequent water changes. Changes in temperature or water chemistry will also take place more quickly in small aquariums. Rapid changes in the temperature or water chemistry are harmful for fish. Fish aquariums come in many shapes ranging from rectangular to hexagonal or even cylindrical or spherical. While making your purchase, it is not only the beauty of the piece that counts. Ordinary matters like how easy it will be to clean out the aquarium regularly, and how to keep all the nooks and crannies hygienic are important considerations. The height of the aquarium is also a very important aspect. An aquarium that is very deep is complicated to keep for the beginner aquarist. Increased height means greater difficulty when cleaning and your aquarium might therefore always carry some amounts of waste even after a thorough clean up. Poor light penetration is another problem with a deep aquarium. Plants will not thrive in water that has poor light penetration and special lighting is therefore needed in deep planted aquariums. Moreover, human eyes are designed to view rectangular things rather than materials of varied shape. It is always better to use larger or at least moderately sized tanks since it is easier to keep a larger tank in good condition. And rectangular tanks have more surface area exposed to air, increasing the scope for more oxygen dissolving in water; a factor which can increase the number of fishes that could be accommodated in the tank. Principal considerations for selecting fishes for aquarium are colour range, compatibility for co existence, cost, adaptability to environmental conditions, feed preferences and disease resistance. Common Tank Sizes and their Capacities: Maximum Tank Length Width Depth Surface Volume fish weight (cm) (cm) (cm) are (cm2) (cm) capacity (kg) (no.) 30 15 15 450 8 8 15 45 25 25 1,125 35 35 38 60 30 30 1,800 67 67 60 90 30 30 2,700 101 101 90 120 30 30 3,600 135 135 120 - 2 - IMPORTANT FRESHWATER ORNAMENTAL FISHES 1. Gold fish:- More than 20 varieties of goldfish are available, with variegated colours and shapes. Given proper care their life span is up to 25 years. 2. Guppy: Their longevity is 3-4 years. Excessive feeding decreases their lifespan. Males show a spectrum of colours. It gives birth to young ones (live-bearing). Guppies can survive in poorly oxygenated water. 3. Kissing Gourami:- It has accessory respiratory organs and therefore can live in low oxygen levels. Due to its pleasing colour and behavioral peculiarities, this is a widely welcomed ornamental. 4. Paradise fish:- Though beautiful, it has a tendency to attack other fishes and therefore usually not suggested for keeping with other fishes in a tank. 5. Platy:- It has maximum colour range among freshwater ornamental fishes. They are live beares. 6. Sword tail:- They are noted for their beauty and peculiarities of breeding. They also give birth to young ones. 7. Zebra fish:- It has spectacularly coloured lines on the body and hence the name. They are carnivores. 8. Angel:- Although silent in posture and movement, the fish frequently attacks small sized fishes. Many varieties are available. 9. Mollies:- More than ten varieties are present and are live bearers. 10. Fighter:- Males are more colourful than females. Two males are never kept in a tank along with females because they fight each other for mating with female. 11. Orange chromide (‘pallathi’):-A near relative of pearl spot (‘karimeen’); the fish has numerous orange spots on the body. They can be bred and reared in aquaria. 12. Sucker:- Brilliant colours are not available in suckers. But they are considered in aquarium due to their cute shape and behaviour. They clean the aquarium by feeding on algae. WORLD AQUARIUM FISH TRADE AND PRESENT STATUS During the last four decades, there has been considerable growth and diversification in the international trade in ornamental fishes which is valued at about US $ 5 billion. The major players in this market include USA, Europe, Japan, Australia, Singapore, Indonesia, Philippines and Sri Lanka. In recent years much interest has been shown by the home hobbyists and public aquaria to keep marine ornamentals. The proportion of marine fish in the total global trade has increased from less than 15% to about 40%. The market for ornamental fishes consists of 99% home-hobbyists and 1% - 3 - public aquaria and research institutes. The market is mostly located in areas with high density population, industrial areas and cool climate. The industrial chain which determines the price is explained as: Fisherman/Breeder Exporter Airline Importer/Wholesaler Retailer Hobbyist The importer/wholesaler plays a very important role as the link between producer and consumer. Only perfect, good and healthy fish have good market value. The extra cost of quality control in a fish house (at both export and import level) with good seawater management and trained staff thus adds to the value of the fish. According to statistics, 50% of the suppliers are located in Asian countries. Singapore. Thailand, Hong Kong, Japan and Malaysia are the major suppliers of freshwater fish, while Indonesia, Philippines and Sri Lanka are the major suppliers of wild-caught marine fish. Philippines is known for the direct export of marine exotic varieties. Singapore exports relatively few salt water fish. Originating from its own resources but depends mainly on re-export of Indonesia-caught fish and invertebrates, while Sri Lanka exports her reef fishes and fishes coming from Maldives.