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