Posts tagged “Water Fountain”

Feeding Daphnia It should come as no great surprise that daphnia are an excellent source of nutrition for small fishes; countless species the world over have heavily relied upon this abundant resource for eons. Fish keepers have been touting the benefits of feeding live daphnia for about as long as people have been keeping fish. The nutritional value of live daphnia depends greatly upon what it eats. Direct enrichment of daphnia is easy and effective. Choose a smaller alga with a well-rounded fatty acid profile. Tetraselmis green alga and Spirulina alga are excellent choices of feed and can be found in aquatic supply stores, along with other algae options. One may supplement B-vitamins with the use of active baker’s yeast, though only very sparingly due to its ability to quickly foul the culture water. Daphnia are typically about 50 percent protein by dry weight, and moina even a bit more, making them especially useful for growing out juvenile fish. The use of an automatic feeder is best, though daily manual feeding will suffice. Store-bought frozen algal pastes are a nutritious and cost-effective source of food. Enough food should be added to produce a green tint to the water (approximately 105 to 106 cells/ml). Culture water should not be allowed to clear for long, if at all; at the same time, one must always be careful to avoid overfeeding. ,Harvesting Daphnia to Feed to Fish Only one of the two vessels are harvested at a time. Using a rotating schedule, one vessel can be harvested every one or two days. Harvest is best undertaken a few hours after re-greening the culture water, as to allow for maximal enrichment of the daphnia. To collect the animals, it is best to use an appropriately sized (something on the order of 50- to 150-µm) plankton screen. A short length of tubing can be used to direct the water through the drain to the screen, which should sit in some water to avoid leaving small air bubbles on the animal. The harvested batch can be temporarily transferred to a bottle before being fed out to the fish, but should be used as soon as possible. Harvests will generally alternate between the two vessels; however, always harvest and restart any culture that appears to be declining. Take care to avoid feeding spoiled food; all thawed, unused portions of algal paste must be refrigerated and used within a few days or discarded.,By Kenneth Wingerter Properly caring for even a small, simple aquarium system can be fairly time consuming, leaving many aquarists eager to cut a corner or two to save a little time. One common way that fish keepers accomplish this is by using prepared, store-bought foods. To be sure, the measured use of certain high quality prepared foods is usually acceptable. The inclusion of some whole frozen items is markedly better. And a highly varied combination of prepared and frozen foods is better yet. But whatever the feeding regimen, the use of live foods has been proven time and again to greatly enhance the immunity, digestion, growth, coloration, and general health of captive species. Further, it offers the opportunity to observe the natural feeding response of one’s aquatic animals. Certain small cladoceran crustaceans, such as Daphnia and Moina, not only serve as highly nutritious live food items, but are quite easy to culture in perpetuity. Meet the Cladocerans: Daphnia and Moira Daphnia spp. and Moina spp. are closely related and belong to the animalia order Cladocera. (Editor’s note: For the sake of brevity, the author is using the species name Daphnia throughout most of this article to refer to both daphnia and moira.) The cladocerans are a group of small, primitive, and mainly freshwater planktonic filter-feeding crustacea. They have a carapace that covers the entire body except the head. Their flattened, leaflike legs (or phyllopodia) are used for suspension feeding as well as for respiration. Cladocera are commonly referred to as water fleas due to the hopping motion they make when moving about in the water. Daphnia are distributed throughout much of the world, though they are less abundant in the tropics where water bodies are usually nutrient poor (only six of the 50 daphnia species occur in the tropics). They prefer warm, still, or slow-moving waters with heavy organic loads. These may be ephemeral bodies of water, like rock pools, where conditions only sporadically allow for growth and reproduction. 

 Anchor Worm Infection In Fish There are many skin parasites that infect fishes. One such parasite is the anchor worm. However, despite its name, it is not a worm, but a large, parasitic crustacean of the Lernaea species. And although the parasite can infect any fish, pond fishes are most susceptible. Once attached to the fish’s skin, it buries its head deep into the muscle tissue. Symptoms and Types A fish infected with anchor worms will have red and inflamed skin irritations. Take a closer look, and you can see the parasite’s body sticking out, appearing like whitish-green threads. The fish will also rub or brush itself against objects, in an attempt to get rid of the anchor worm(s).