Dozens of species of starfish exist in the pet trade, most of them omnivorous scavengers. They will find some food in the tank, picking up leftover fish food, algae and so on; but since a fish tank is much smaller than their natural habitat, meaning they probably will not find enough to sustain them. Unless you want your starfish to fade away, you’ll need to supplement whatever he finds for himself with fresh food.
Confirm identification of your starfish by comparing him to images in an online or print reference. Measuring or estimating his width from opposing arm tips might help; you can rule out any species smaller than he is, as well as those with a different number of arms. Aquarium suppliers do not always identify their animals correctly, especially invertebrates. About 2,000 species of starfish exist, most of which are never sold for aquariums, so you should not have that many to search through.
Obtain information on species diet. Most of the starfish available in the pet trade eat the same sorts of things, but a few have more specialized diets. For example, the infamous crown-of-thorns starfish eats mostly coral polyps while the morning sun star's diet consists primarily of other starfish.
Prepare a few chunks of the appropriate food; this will often be meaty foods such as shrimp or mussels. Slice them into cubes that are considerably smaller than the starfish. Do not cook the foods.
Pick up a chunk with aquarium forceps and drop it over the starfish or place it beside him. If the chunk was small and he devoured it quickly, provide another. Feed the starfish about once a week to begin with. How often really depends on the individual. If he doesn’t take a piece of food at all, increase the interval between meals. If he takes it readily and consumes it rapidly, decrease the interval. Always remove uneaten food from the tank within a couple of hours.
- The best time to confirm identification of a starfish species is before buying. Some species of starfish are voracious carnivores and will quickly eat their way through the sessile -- immobile -- invertebrates of a reef tank, especially corals. Feeding the starfish regularly might save some coral in the short term, but you’ll probably need to set up a new tank if you want to keep both starfish and reef animals.
starfish image by Christopher Meder from Fotolia.com
Judith Willson has been writing since 2009, specializing in environmental and scientific topics. She has written content for school websites and worked for a Glasgow newspaper. Willson has a Master of Arts in English from the University of Aberdeen, Scotland.