Å ha en revtank kan være en utfordring fordi det er så mange forskjellige typer koraller å velge mellom. Før du starter revtanken, gjør deg kjent med de forskjellige typene koraller. Når det gjelder å sette opp en revtank, vil koralltypene du velger å lagerføre tanken din ha en direkte innvirkning på suksessen din. Hvis du er ny på saltvannsakvariehobbyen, kan det være lurt å starte i det små med noen få hardføre korallarter og jobbe deg opp til de mer «avanserte» artene. Med mindre du gjør litt undersøkelser på forhånd, vet du kanskje ikke hvilke typer koraller som anses som «nybegynnere». Denne artikkelen vil gi deg en generell oversikt over de forskjellige typene koraller som brukes i revtanker, slik at du kan være sikker på at du lager tanken på riktig måte. Harde VS myke koraller

Corals can be divided into two main categories: hard corals and soft corals. Hard corals are made of rigid calcium carbonate, or limestone, and they often resemble rocks. These corals develop an internal skeleton that grows as the coral matures and stays in place after the coral dies. With each new generation of polyps, hard corals grow larger and larger. Hard corals do not move and they also have a very slow growth rate – they also do not tend to be as colorful as soft corals. Hard corals derive much of their color from the various types of algae that grow on their surface.
Myke koraller er også sammensatt av stivt kalsiumkarbonat som harde koraller, men det er kombinert med protein slik at det er mindre stivt. Denne typen koraller har ikke et eksoskjelett, så den er i stand til å bevege seg – myke koraller ser ofte ut til å svaie i en lek fordi de påvirkes av vannstrømmen i tanken. Mange arter av myke koraller er tolerante for varierende vannforhold, og de er lettere å ta vare på enn mange arter av harde koraller.
Typer harde koraller

Corals grow in compact colonies made up of individual “polyps” – spineless animals that are typically only a few millimeters wide and a few centimeters long. Hard corals, also called stony corals, often exhibit a branching or plated structure and they are generally more difficult to keep than soft corals. There are two types of hard coral – large polyp stony (LPS) and small polyp stony (SPS). LPS corals have smaller skeletons with voluminous tissues growing on the top – these corals may use water inflation to help keep their shape. SPS corals have dense, heavy skeletons made up myriad tiny polyps which form a sort of ‘skin’. This type of coral is adapted to strong water flow but requires a great deal of sunlight to thrive. Hard corals are known by the scientific name “scleractinians” and there are a number of different species.

Noen av de mest populære artene av harde koraller for revtanken er hjernekoraller, tusenfrydkoraller, boblekoraller, staghornkoraller, fingerkoraller og hornkoraller. Hjernekoraller er ganske enkle å ta vare på i hjemmeakvariet, men de er en semi-aggressiv art som er utsatt for å stikke andre typer koraller. Daisy-koraller kalles også noen ganger rørorgankoraller, og polyppene har et tydelig stjerne- eller blomsterlignende utseende når de er åpne – av denne grunn kan de lett forveksles med stjernepolypper. Daisy-koraller krever en moderat grad av omsorg med moderat til høy belysning, men de er en fredelig korallart.
Boblekoraller er lett å identifisere fordi polyppene danner oppblåste, boblelignende sekker. Denne typen koraller er lett å ta vare på, men det er en veldig aggressiv art – det er også viktig å merke seg at de kjøttfulle polyppene er svært skjøre, de kan lett bli punktert. Boblekoraller kommer i en rekke farger, og den krever kun lav til moderat vannføring og moderat belysning. Staghorn-koraller produserer en rekke forskjellige former og strukturer, men skjelettene deres har en tendens til å være veldig porøse og lette. Denne typen farge er ganske vanskelig å ta vare på fordi de krever svært stabile tankforhold og høy belysning. Fingerkoraller er oppkalt etter den fingerlignende formen på stilkene. Denne typen koraller er fredelige, men du bør fortsatt gi den god plass i akvariet – du må også sørge for at den har høy belysning.
Typer myke koraller

This group of corals belongs to the order Alcyonacea which includes several suborders and families. Unlike hard corals, soft corals have fleshy skeletons that may exhibit various types of movement. The bodies of soft coral are made up of spiny sclerites which provide structure for the coral while also creating a spiky texture that deters predators. These corals are more flexible in terms of placement in the reef tank as well – they can adapt to low-light conditions as long as they receive adequate nutrition. Soft corals come in a wide range of shapes and colors and they are also capable of expanding and retracting.

Some of the most popular types of soft coral for the reef tank are blue corals, pipe corals, green star polyps and tree corals. Tree corals have thin stalks compared to other corals and they do not have any polyps on the stalk – they produce thin branches and branchlets that form polyps. Star polys come in three different colors – white, brown, and green – and they are named for the star-like arrangement of their polyps. These corals are a good choice for beginners because they are fairly easy to maintain compared to other corals, just be sure they get enough lighting and they have high water flow. Blue corals produce plate-like or form columns and their skeletons are made of aragonite. This type of coral can develop small feathery polyps that have an olive green or whitish gray color but the interior turns blue due to its ability to extract iron from the water.
The types of corals you choose to stock your reef tank may depend on the size of your tank as well as your experience in the saltwater aquarium hobby. If you are new to the hobby you may want to consider starting out with a few small soft corals because they are more forgiving of changes in water conditions. For nano reefs, however, small species of hard coral are often recommended because they have a slow growth rate and will not outgrow the limited space of a nano tank.
Before you stock your reef tank, take the time to research a few different species of coral to make sure you select the type that is right for you. Different species of coral have different requirements in terms of tank lighting and water movement, so match your corals to the conditions in your tank for the best results. You can also design your tank to cater to your corals if you are starting a new tank.