sera guide - Healthy pond fish

33 6.7 Treating fish leech infections Diagnosis: page 16 Fish leeches belong to the jointed worms (An- nelida) phylum which also includes many well known non-parasitic species such as earth- worms or Tubifex. Fish leeches use their oral suction cup to attach to fishes and suck their blood. While doing 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. Dangerous secondary infections often occur at the spot where the leech sucked blood. Furthermore, the leeches may transmit para- site stages while sucking blood that they took up the previous time they sucked blood from another fish. Fish leeches or cocoons with their offspring can be introduced with newly purchased fish, live food, aquatic plants or water birds landing on the pond. Frequent water changes, collecting the worms and carefully cleaning the rocks, the bottom ground and the plants reduces and finally entirely removes the leech population. (Unfortu- nately this is a rather laborious but necessa- ry procedure.) In case it is necessary to remove leeches from the fish itself, e.g. in case of a mass infestation, you should remove the worms very carefully with an edgeless pair of twee- zers close to the front suction cup. Avoid squeezing the stomach of the worm (in the middle), as the leech in this case regurgi- tates its stomach contents into the wound, thus increasing the risk of transmitting a disease. The same applies for other mea- sures 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. sera pond cyprinopur helps combating the leeches and the diseases caused by them. Applying sera ectopur supports wound healing of the suction spots and prevents infections. Fish leech Fish leech / Piscicola sp. 6.8 Treating crustacean infections The large group of crustaceans (Crustacea) also includes some species that live parasiti- cally on pond fish. In spite of their some- times misleading names (e.g. fish louse and anchor worm) and their often unusual appearance, all parasites mentioned in the following are crustaceans. Bloodsucking crustaceans are a threat for fish not only because of the loss of blood and the possible infection of the wounds, but also transmit different pathogens from one fish to the next one. There is an addi- tional group of crustaceans that do not live parasitically themselves but serve as inter- mediate hosts for other parasites. Fish can therefore become infected with parasite stages if they eat these crustaceans (e.g. Copepods may be intermediate hosts for tapeworm larvae). You can prevent introduction of these crus- taceans by not using potentially dangerous frozen and live food (all sera foods are guar- anteed to be parasite free) and being careful when purchasing new animals and plants (e.g. by quarantine measures). Also be aware of water birds that may introduce these crustaceans into the pond. sera pond cyprinopur is used in case para- sitic crustaceans occur in spite of preventive measures. Applying sera ectopur supports wound healing and prevents infections.