sera guide - Healthy pond fish

34 Diagnosis: page 18 Treatment: see above Isopods also belong to the crustaceans. Some species parasitize on fish and suck blood there. The loss of blood and the sting injuries weaken the fish. Parasitic isopods Diagnosis: page 17 Treatment: see above The crustacean Ergasilus has pointed clasping hooks that it uses to cling to the gills of the host fish for its entire life. Only the females live as parasites on the fish where they feed on skin cells. The males swim freely in the water. The females develop two large egg sacs at the back end. Infected fish suffer from constant severe shortness of breath due to the constant gill irritation and the increased formation of mucus. Partially irre- parable damages and dangerous bleedings occur at the gills. There are frequent second- ary infections. Gill infecting cope- pod, Photo: Dr. Sandra Lechleiter Parasitic copepod / Ergasilus 6.8 Treating crustacean infections Diagnosis: page 16 Treatment: see above Fish lice are good swim- mers. They look for a fish as a host in free water and attach to its skin using their two suction cups. They suck blood (sometimes for weeks) and often change the spots they attach to while doing so. Some species additionally inject a toxin or an allergen, which may cause infection or intoxication symptoms up to death. Furthermore, they may transmit pathogens from one fish to another while sucking blood, including spring viremia and Erythrodermatitis in Koi. The affected fish are always weakened due to blood loss. There are frequent secondary infections. Some members of the copepod group are intermediate hosts for dangerous parasitic worm species. Fish can become infected if they eat them. Other copepod species are parasites themselves (e.g. anchor worms and gill infecting copepods such as Ergasilus sp.) and as such threaten the fish. These parasitic copepods attach to fish by means of special structures and suck their blood. As an adaptation to their specific way of life, their body shape can often hardly be recog- nized as a crustacean. Argulus Fish louse / e.g. Argulus Diagnosis: page 17 Treatment: see above The crustacean Lernaea is usually called “anchor worm” by ornamental fish keepers, as it is deeply burrowed in the fish skin with a branched attaching organ on its front end, and has an elongated body shape without any visible limbs. There are two sacs at the back end of females in which the eggs deve- lop. The fish are weakened very much by the constant loss of blood and severe infections at the deep attachment spots. Anchor worm / Lernaea Strict hygienic measures such as repeated water changes and the careful cleaning of rocks, bottom ground and plants reduce the population of the parasitic crustaceans until they finally disappear entirely (please also refer to the information about sera med Professional Argulol in case of severe prob- lems with parasitic crustaceans).