Nutrition and Reproduction
A well-balanced and complete diet is necessary for the successful maintenance of all aquatic creatures. In some hardy and readily bred species, a solid diet may be enough to support captive reproduction. However, many animals require additions to their diet as breeding time approaches.
In certain species, the presence of a certain type of food may actually be a stimulus for reproduction. Unfortunately, specifics in this area are lacking. As you read and research, be sure to note the environmental changes that your pets experience in their wild state. If drastic changes such as floods or droughts regularly occur, it is likely that the animals will be exposed to important dietary fluctuations that may influence reproduction.
The specific facts will vary from species to species. In general, it pays to play it safe by increasing the amounts and varieties of foods fed to pets that appear to be approaching breeding condition. Live foods work well for many species, even those that do not necessarily prey upon other creatures on a regular basis. The addition of growing aquatic plants or algae, or fresh vegetables, may well be the key for herbivorous species. You might also try varying the usual diet by including new foods such as fish roe or small, whole shrimp.
When contemplating the birth of a brood of fish, it is important to plan ahead to acquire the foods that will be necessary. There are currently available a wide variety of foods designed especially for young fish. For many, however, tiny live food items such as rotifers and infusoria are preferable and, in many cases, necessary. This holds especially true for the young of predatory species, which may not recognize nonliving foods.
One of the most important steps that you can take to ensure success in raising large numbers of small fish is to establish a thriving colony of infusoria. Freshwater or saltwater infusoria can easily be cultured in a well lit aquarium or one placed in a sunny location. The water should be gently aerated and a bit of yeast, shrimp, and hay should be added to the aquarium. Many of the tiny creatures that will develop are nearly invisible to the naked eye, so you may wish to confirm their presence by using a magnifying glass or microscope. A number of algae species should also establish themselves, and their presence will be beneficial to the culture. Even the tiniest of fish species will readily consume infusoria and will grow rapidly on this rich diet. As the fry increase in size, enriched brine shrimp and other suitably sized foods can be introduced.