Snails

Gastropod mollusks--snails--probably are not very high on anyone’s wish list when thinking about animals to add to a new saltwater aquarium. Whoever said snails were exciting? Even so, after the first wave of film or filamentous algae appears, keepers are often diligently researching snails and doing some eleventh-hour clean-up crew shopping. Even the most meticulously maintained of aquaria will develop algae problems from time to time. The best way to confront these plagues is biologically. And the best biocontrols for benthic algae, arguably, is snails. But snails can do much more than just algae-eating to keep an aquarium clean. Over time, detritus may accumulate in areas of low flow. These settled particulates are of little nutritive value and so are ignored by most creatures. Even so, they support the growth of unwanted bacteria and serve as a store of excess phosphate. Eventually, these wastes can settle further and further into the aquarium substrate where they become increasingly difficult to remove through conventional means (siphoning, mechanical filtration, etc.); here, they can turn into a biological time bomb. That is, unless you have lots of detritivores. Certain snails (e.g. Nassarius) are the choice aquarium detritivores. These critters mop up settled organic wastes, including detritus. They are capable of reaching detritus both above and below the substrate surface. As they forage within the sand bed, they additionally help to oxygenate areas that have gone hypoxic due to the decaying organic matter therein. For sure, the ideal reef aquarium stocking plan features a variety of snail species that includes both herbivores and detritivores. In this section, you will learn which species (and number of specimens) is ideal for your particular clean-up crew.