July 1957 School Magazine

Brisbane Girls' Grammar School Maqazine

July, 1957

July, 1957

Brisbane Girls' Grammar School Maqazine

Kendall Broadbent Natural History Essay, 1956. LOOKING IN THE GLASS BOWL

splendens), and the Ange l Fish (Pteryphyllum eimekei). The Swordtails, which may be either red, green, black or albino, are curious· in that the male has a sword-like development of the bottom ray of the cordal fin. The Siamese Fighting Fish which, as the name suggests, comes from South-East Asia, may be dark blue with the body suffused with red or others may be red, lavender or green. The males have a passion for fighting and must be kept apart. In Siam contests are held between these fish. Differing greatly from these is the gentle Angel Flsh which, with its long sail-like fins and its bold black bands on a slver background and with an occasional fleck of metallic blue, must surely be the monarch of the aquarium. Being such beautiful and tender creatures it is impossible to neglect them and although many people believe that they can be left for a long period without food, it is as cruel to do this as to starve any other animal. The fish learn to know the hour of feeding and the person who feeds them, if this is done regularly, and they can be seen to swim towards the surface of the water if there is a possibility of food a t their regular hour of feeding. They love a change of diet and although such foods as Daphnia, the eggs and larvae of insects and prepared foods are eaten with relish, I have found that the mosi loved dish of all is an occasional scraping of scrambled egg. Fish are affected considerably by their environment. The size of the bowl in which they are kept has a considerable effect on their growth as I have noticed from an experiment I carried out this year. From a number of fish which were born .in February, two were separated and placed in bowls" of dif- ierent size. Whereas the one placed in a large bowl had reached its· adult size after about four months, the one placed in the smaller bowl had grown less than a quarter of an inch in this time. Fish are fully aware of happenings in their surroundings and remember these happenings. This may be seen very clearly if one visits a professional breeder. The fish, remem- bering what has happened to their companions on previous· occasions, may be seen to swim to the bottom of the pool or to hide amongst the weed when the breeder approaches with a net but were he to approach with food the same fish would swim to the surface. ' Thus the splendour and oddities within the magical bowl transport one's mind into a fairyland and while in this state one's nerves are completely relaxed and it is for this reason that many doctors and dentists have placed bowls of tropical fish in their waiting rooms. - MARJORIE NEIL 15

"Looking in the Glas·s Bowl" would immedia tely suggest to most people the use of magic in foretelling the future. How- ever, there is one glass bowl into which one may gaze and the magic of the beauty contained within that glass bowl will immediately transport one's mind to a fairyland. This magical glass bowl is, of course, one containing exotic tropical fish. If the fish are to be kept healthy and contented, much care must be taken in preparing their home. The size of the bowl must be taken into cons'ideration when deciding the number of fish to be put in it as fish require a certain amount of water each. As fish require oxygen the water must be well aerated and this is done by the planting of certain weeds and ferns which, as well as providing oxygen for the fish, remove carbon- dioxide from the water and beautify the bowl. Also necessary for the continued health of the bowl is the presence of snails, many of which, such as the Ramshorn snail (Planorbis Corneus) are very beautiful. The snails con- sume much of the unwanted food and Algae but their own excreta replaces this. Their eggs are a source of food for the fish. As part of the diet of snails includes fish ova, it has· been found necessary to remove snails from a bowl which is to be used for breeding. It has been stated that if the correct number of fish and snails and the exact amount of food were put in the bowl, it would never be necessary to change the water in the bowl, however, I have never attained this peak of perfection and find it neces·sary to clean the bowl regularly, The real enchantment of the bowl is undoubtedly the fish . Among the smaller fish , Neon Tetra (Hyphessobryeon innesi), with its almost electrically brilliant blue-green streak from head to tail and the blood-red colouring on parts of its body, is probably the most beautiful. Almost equalling this in beauty a re the White Cloud Mountain Minnows (Tanichthys albonubes) and the Guppies (Lebistes reticulatus). The White Cloud Mountain Minnows are similar to the Neon Tetras in that they, also, have a streak down their bodies but it is gold on this fish. The males of the Guppies are very beautiful and are best described by another of their names, "Opals." No two male Guppies have the same colouring or the same shaped fins. Among the larger fish the most beautiful are probably the Swordtails (Xiphorporus helleri), Siamese Fighting Fish (Bet-ta

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