sera guide - Healthy pond fish

32 6.6 Treating flatworm infections Diagnosis: page 15 Gill flukes (Dactylogyri- dea) live as parasites mainly on the gills of fish. The gill filament irrita- tions and injuries caused by their clasping appara- tus induce increased mucus formation that inhibits gas exchange more and more, finally making it possible that the fish suffocate. Dactylogyrus can be distinguished from Gyrodactylus, among others, by the pres- ence of pigment eyes at the front end. The differences to the livebearing skin flukes is relevant for the treatment: As the gill flukes lay eggs whose shell is impermeable for the active agent, a second treatment must be carried out as to kill the larvae that have hatched in the meantime as well. In case of unclear diagnosis better surmise a gill fluke infestation and treat twice with sera pond omnipur for safety reasons. Development of the worm larvae depends on the temper- ature. The development time in the pond should usually be between 5 and 14 days, depending on the water temperature. The second treatment should be carried out somewhat sooner or later (usually scheduled after 7 days), according to the current water temperature. Gill filaments with Dactylogyrus infestation Gill flukes / Dactylogyridea Metacercaria cysts on the gill filaments Diagnosis: page 15 Flukes of the order Gyrodactylidea are more likely to be found on the skin than on the gills of the fish. They can also be distinguished from gill flukes (Dactylogyrus) by their lack of pigment eyes at the front end. The worms attach to the skin of the fish with the clasping appa- ratus at their back end. Their mucous mem- brane becomes thicker as a defensive reac- Gyrodactylus sp. with three larvae, one inside the other Skin flukes / Gyrodactylidea Unlike the Monogenea, Digenetic tremato- des require one or several intermediate hosts for completing their development cycle. Snails serve as fist intermediate hosts. Later larvae stages may infect fish and cause damage while wandering through the body of their host (e.g. in the eyes as a so-called worm cataract). Black spot disease is another common symptom of an infestation by the larvae. Fish may also be the final hosts, i.e. the host of the adult, mature worms. Fish can be severely weakened or even killed in case of strong infestation by the larvae or adult trematodes. Most fish tolerate a slight infestation by flukes (Monogenea) well. The injuries caused by the hooks of the clasping apparatus of the worms only be- come a problem if mass multiplication occurs due to other weakening influences. In that case, more and more secondary infections appear on the affected skin or gill regions. tion. The occurring skin injuries often lead to secondary infections. While an infestation with only a few flukes often runs symptom free, a mass infestation may quickly cause the death of many fish. Therefore treat with sera pond omnipur according to the information for use in time.