sera guide - Healthy aquarium fish

6.7 Treating fish leech infections Diagnosis: page 17 The larvae of this worm penetrate the skin of a fish where they live under its scales until they are mature. (The adult animals are about 3 – 5 mm long and creep around on the skin. They are transparent and hardly visible.) The infection leads to inflammations and – in case of severe infestations – even to large area de- struction of the fish skin and consequently death of the fish. Transversotrema require snails as intermediate hosts. Multiplication and spreading of the parasites therefore can be re- duced by removing snails (you can, for in- stance, use the sera snail collect trap for this purpose). The worms themselves are removed Transversotrema sp. with sera omnipur or sera mycopur. The dead larvae (underneath the scales) are reject- ed by the tissue after a while. Larvae of other flukes (so-called Metacerca- riae) wandering through the body of the host fish may cause damages that lead to some characteristic disease symptoms, such as worm cataract (the eye becomes cloudy) and black spot disease. Diagnosis: page 18 Fish leeches belong to the jointed worms (Annelida) phylum which also in- cludes many well known non-parasitic species such as earthworms or Tubifex. Fish leeches use their oral suction cup to at- tach to fishes and suck their blood. While do- ing so they inject hirudine into the wound, a substance that inhibits blood coagulation. The full worm lets go of the fish at the latest after 2 days. While sucking blood it injures the skin of the fish (less frequently gills or fins). The loss of blood itself – including secondary bleedings – always causes weakening, in case of smaller fish sometimes even immediate death. Danger- ous secondary infections often occur at the spot where the leech sucked blood. Further- more, the leeches my transmit parasite stages while sucking blood that they took up the pre- vious time they sucked blood from another fish. Fish leeches or cocoons with their offspring can be introduced with newly purchased fish, live food or aquatic plants. Frequent water Fish leech Fish leech / Piscicola sp. changes, collecting the worms and carefully cleaning the decoration and the plants re- duces and finally entirely removes the leech population. Larger cichlids like to eat leeches and should be used for combating them, pro- vided the remaining fish stock allows this. In case it is necessary to remove leeches from the fish itself, e.g. in case of a mass infesta- tion, you should remove the worms very care- fully with an edgeless pair of tweezers close to the front suction cup. Avoid squeezing the stomach of the worm (in the middle), as the leech in this case regurgitates its stomach contents into the wound, thus increasing the risk of transmitting a disease. The same ap- plies for other measures that might irritate the worm (e.g. by sprinkling salt directly on the worm). It is safer to remove the worm from the tank only after it left the fish by itself. Applying sera ectopur supports wound healing of the suction spots and prevents infections. sera baktopur provides help in case of already ex- isting infections. 6.6 Treating flatworm infections 35