Scutariella are flatworms that are specialized shrimp ectosymbionts or parasites. Scutariella have been proven to live on shrimp from East Asia, India, Sri Lanka, but also from Central Europe and the Balkans.
This whitish worm belongs to the Scutariellidae family. It grows to approximately 2 mm in length and has two lobular tentacles on the end of its head and a sucker at the bottom end. It is often found in the gill cavity of shrimps, but also on the basis of their antennae and the rostrum.
Treat as per Hydra and Planaria: betel nut extract ("Planaria Zero") and Fenbendazole, purported to be "shrimp safe".
It does not particularly harm the shrimp and "Planaria One" has been reported to get rid of them promptly and safety. Others report it is not entirely shrimp safe. Made from betel nut it is advertise to be safe for invertebrates however anecdotal reports of it killing snails and shrimp exist. Others report using it half strength and not losing even tiny young shrimp.
It looks like there are three ways to kill these, hydra and planaria. This is of interest to people other than shrimp keepers as planaria and hydra are problems that affect people that breed fish as well.
Betel nut extract ("planaria zero") and Fenbendazole are both used, some have had success others have killed shrimp and snails with them.
"Some people may find the shrimp are fine with Fenbendazole but others may not, it depends how sensitive the shrimp are. But in any case if you use Fenbendazole, you will need to perform water changes immediately after the treatment, or else the result may potentially catastrophic.
If a tank is infested with hydra, H2O2 is a safer alternative to treat the tank. Dosing 1ml per 4 litre of water for 2 to 3 days is lethal enough to kill most hydra and algae. But it will not affect higher form of creatures. Given said that, some shrimp may not like it too. (I personally have not had any luck with H202 like this. - RJS)
"some of the so call "Aquarium Safe" planaria, hydra and algaecide uses salicylic acid (a.k.a Asprin/ASA) as active ingredient. These sort of products will claim that it uses natural ingredient derives from plant. BUT... Don't go and start dumping aspirin into the tank like fenbendazole. Aspirin is not water soluble and it has to be dissolved in solvent first and is still not 100% shrimp safe.
It is better to treat and quarantine the plant before use. Usually, I will treat the plant with diluted H2O2 for 10 to 20 minutes. After that, I will treat them with diluted HCL or undiluted Revive Vita for 2 to 10 mins (depending on the plant type). Then I will soak them for a week or two." - shrimpydaddy
Ref:
http://www.shrimpspot.com/topic/3174-hydra-post/?page=2
