Scientific name: Derbesia sp.

Family   Derbésiacées (algae)

  Common name: Filament

English name: Hair algae

Description:

  Green algae to filamentous, the thickness of a human hair, forming dense clumps lining the substrate.     

    Maximum Size:

up to 25 cm long according to the species.

Origin:

  certainly the whole  world

Rarity

  currently arrives with living stones.

Ecological Description:

Each substrate  exposed to light may be colonized.  

Risks:

Invasive, most often caused by a high concentration of nutrients (nitrates, phosphates) and trace elements. Sessile invertebrates are quickly covered and smothered.

Council:

These algae can appear during the startup phase in a tank, and they usually disapperar by themselves or  by the introduction of herbivorous animals thereafter.

In the case of an invasion, before considering any means of struggle, it is preferable to determine (the) cause (s). Proceed to test first the water to detect possible pollution before trying to find its origin. Check the operation on equipment, review all the changes on the tank before the appearance of those algae.

Meanwhile, manual eradication will help a little to contain the invasion. But it is advisable to perform this operation while siphoning or filtering on Perlon through an external filter. Indeed, the algae would quickly colonize new areas where the current carries them to.

Once the source found and corrected, one may help to make it regress, depending on the capacity of the tank, thanks to animals that consume such as Turbo snails, sea urchins and hermit crabs. The blennies are fishes that can be of great help against the filamentous algae species and compatible with our limited volumes.

  Promoting the growth of higher algae such as Caulerpa sp. helps to fight against this alga on the principle of probiotics. Indeed, the Caulerpa will consume dissolved nutrients and thus compete with filamentous monopolizing this trophic link.

Other species may sometimes be designated by the term "filamentous", they are  Cladophora sp. and Bryopsis sp.