Argulus or Fish lice is a type of crustacean parasites that will attach onto the skin and fin surface and draw blood from its host. It actually looks like a flattened disc (about 0.3-0.5cm) and the parasite can move from one host to another. Fish lice is usually introduced to an aquarium when the owner did not realize that the new fish already has the parasite attached onto it. Note that fish lice is actually native to tropical countries and because fish are exported elsewhere to every continent, the fish lice will actually unintentionally brought along.Infected fish will often swim in an erratic manner trying to scratch itself on the aquarium surface in order to get rid of the parasite. The open wound and lesions caused by the needle piecing (inflicted by the parasite) is often exposed to secondary infection and thus it is very important that the fish lice must be killed as soon as it is detected. Fortunately, there are anti-parasite formularies available in aquarium fish shop, which can help to get rid of the parasite.
Lernea Elegans or Anchor Worm is as dangerous as fish lice and it is a common problem affecting tropical fish. The parasite is highly contagious and the worms will actually release eggs that will infect the whole aquarium community. It appears as an elongated Y-shape straw and it lodges itself under the scale of the fish causing sores and lesions. However, unlike fish lice, it doesn’t move around once it attached itself but it will release offspring and multiplies in large numbers.The only way to deal with the problem is to actually scoop up the infected fish and place it on a damp cloth. Using tweezers, carefully remove the worm attached to the fish. Removal will cause bleeding and be prepared to reintroduce the fish back to an aquarium with fresh and clean water in order to prevent infection on the open wound. Add in and maintain aquarium salt concentration of 0.5% to help out with the situation.
