| Rearing young fish can be a compelling and | | | | space after the first few weeks for adequate |
| rewarding hobby. The feeding of fry and their | | | | growth and must be sorted out fairly early. |
| space requirements and culling are discussed | | | | The fry of nearly all tropicals can be kept in the |
| below. | | | | small 3- to 5-gallon breeding tank advocated for |
| Two quite recent fish foods have revolutionized | | | | the first 6 weeks unless there is a spawning, say, |
| the rearing of fry. These are mikro worms and | | | | of over 250 per tank. In such a case they will do |
| brine shrimp. Before they were available or had | | | | better if given more room after the first 4 |
| been popularized, raising a tank of two or three | | | | weeks. Goldfish fry will stand equal crowding at |
| hundred young fishes was quite a task. Not all fry | | | | first, but after 2 to 3 weeks they should be much |
| can be started on mikro worms or brine shrimp, | | | | more liberally provided with space, so that by the |
| and some have to be supplied with smaller food | | | | time they are 6 to 8 weeks old there should be |
| for a few days, but a surprising number can eat | | | | only about 5 to 10 per gallon, and progressively |
| them from the start, especially the young of the | | | | fewer as they grow up. |
| mikro worm, though the parents may be too big. | | | | In the goldfish, this process will be accompanied in |
| Thus, newly hatched giant danios (Danio | | | | the usual course of events by quite severe culling, |
| malabaricus), zebra danios {firachydani rerio), | | | | so that the capacity of the aquarium is not so |
| glowlight tetras (Hyphessobry con gracilis), head | | | | badly strained as it might seem at first sight. |
| and tail light fish (Hemigrammus ocellifer) and most | | | | Culling can start as soon as you can see body and |
| of the barbs, to cite only a few examples, can | | | | finnage shapes and sizes. Culling for color is |
| take brine shrimp as soon as they are | | | | impossible until much later. |
| free-swimming. | | | | With all types of goldfish, good shape, finnage, and |
| It is not the size of the young that counts as | | | | color are attained by only a very small number - |
| much as their mouth capacity or even their | | | | less than 1% is usual. With the fancy types, vast |
| willingness to accept a particular food. With any | | | | numbers of "throwbacks" occur, some of which |
| given species, it is easy to see whether they are | | | | are worth keeping as good examples of different |
| eating brine shrimp because their bellies show a | | | | classes, but many are useless. The genetics of |
| red color even when only one or two have been | | | | gold- fish are complex, no doubt made so in part |
| eaten. | | | | by the reluctance of breeders to inbreed |
| It may be observed that not all the fry are taking | | | | consistently and so help to clean stocks up. |
| them, perhaps only the largest, and it must then | | | | Thus, with the goldfish, culling can be severe. It all |
| be decided whether to arrange for supplementary | | | | depends on your standards and on how many |
| feeding of the unlucky ones, or to let them | | | | relatively inferior fish you wish to keep for |
| starve and raise only the biggest starters. It may | | | | disposal or pond stocking. Few will be worth |
| be added that either of these newer live foods | | | | keeping for further breeding. With tropicals, which |
| appears to be a complete and satisfactory food | | | | throw far fewer abnormal or undesirable forms, it |
| on its own. There is no need to worry about | | | | is usually the aim to keep most of the spawning, |
| varying the fishes' diet in the early stages if these | | | | rejecting only a few runts or badly shaped |
| foods are given. | | | | individuals during the first weeks, and later |
| Space Requirements and Culling | | | | selecting those which grow best and have the |
| Young fry can stand much crowding. Even when 1 | | | | nicest general appearance for breeding. |
| 2 inch in length, most species can be packed | | | | These few pointers can get you started on this |
| some 30 or 40 to the gallon. An outstanding | | | | fascinating hobby. Have fun! |
| exception is the goldfish, in which fry need good | | | | |