What's better than something that works, does not suppose a burden and is for free?

In the aquarium we have a clear example: mini brittle stars. They are small invertebrates able to locate and consume the smallest scrap of food or dead animal in the aquarium. They are incredibly flexible and deformable and thus access to the deeper cracks to gather and consume the smallest organic matter before it rots. They are voracious but absolutely respectful with any other inhabitant of the aquarium and if conditions are favorable they will breed easily.

There are many species of brittle stars, of different sizes, with various different dietary habits and. Under the same taxonomic classification we will focus attention on the so called micro or mini brittle stars.

Mini brittle stars, a very prolific invertebrates.

They are very simple and developed invertebrates but with important evolutionary advantages, especially if we talk about breeding. Despite differentiation by sex, these mini brittle stars share an interesting feature: they can breed in both sexual and asexual way, which might explain the important demographic outbursts that we sometimes observe in our aquariums. If one of these invertebrates loses one of its extremities, it will regenerate it in a few days and the split extremity will become a new individual. When a brittle star community has access to enough food, under the right circumstances a mass spawning can happen, in which males and females release their gametes into the water in a similar manner to that used by other invertebrates such as corals and some species of snails. This behavior is triggered at certain events “special”, such as a change in the moon phase, water temperature or simply the release of debris if we stir the sand or clean the filter.

Not pleased enough with all this, some species are hermaphroditic and have the ability to self-fertilize and incubate their offspring in bags, which once mature go outside through a small genital dimple (whhich can cause to its mummy something more than an annoyance).

Mini ofiuras abundantes

And very resistant.

They can withstand important temperature fluctuations, salinity, long periods without food, and even being attacked by predators such as crabs. Their resistance is awesome and as soon as the conditions become suitable again, they will begin to breed and repopulate the aquarium. It will seem that they have disappeared, but many will be hidden in the crevices of rocks or among the seaweed.

With a non appetizing diet.

Most of the mini brittle stars feed on detritus. Some species are selective and have the ability to detect small food particles such as a piece of flake, a food pellet or a small dead invertebrate and hold it with its podiums to take it to its oral disc. Others are not selective and will guzzle all kinds of detritus, which will be processed in their stomach and disposing the non-food portion.

What makes the mini brittle stars a very useful invertebrate for the aquarium is their ability to detect and consume any remaining food even the smallest ones. Nor will make averse to the corpse of a fish or any other invertebrate and will not hesitate to cover it with their bodies and devour it as decomposition allows access to softer areas.

It is suspected that some species can exercise some pressure on some invertebrates such as isopods and amphipods in case they don't find other sources of food, but it doesn't seem to be something common or important enough to rid them from the aquarium.

And very shy.

Mini brittle stars share a common characteristic: they are afraid of everything. They live in communities that provide them with personal protection, are exclusively nocturnal and if something touches one of their legs they will retract it and hide in the first crack they find. Luckily for them, they must not constitute a very juicy mouthful (they are all spine and skin) and there are few animals that show interest in including them in their diet.

All this does not stop them to scout every square centimeter of rock and substrate at nightfall to devour any organic residue left.

Grupo de ofiuras

So good and so little appreciated.

May be paradoxical, but the mini brittle star is one of the great forgotten when we speak of “cleaning teams”. Every hobbyist agree that they are a very beneficial animal and they tend to be present in mature aquariums with a stable biological load (so in a certain way it serves as an indicator), but no one sells them and few are those who ask for them.

Fortunately are common invertebrates in the rock we import, small animals that call for little and offer much. I have always valued them highly and have taken care of them. Whenever I clean a piece of rock or do a disinfecting dip to a coral, I try to pick them up from the bottom of the container and return them to the aquarium before they die. I even throw some fish food granules at night to encourage their breeding.

Mini brittle stars, if you see one in the night there will be probably dozens of them and you can rest assured. No organic rest will rot before being processed by these innocent creatures.