1. Ichthyophthirius multifiliis Presentation by: Lauren Hannan and Chloe Jensen

2.  Kingdom: Protista  Phylum: Ciliophora  Class: Oligohymenophorea  Order: Hymenostomatida  Family: Ichthyophthiriidae  Genus: Icthyophthirius  Species: multifillis

3. Morphology  Adults are as large in diameter as 1 mm  Macronucleus is a large, horseshoe-shaped body that encircles the tiny micronucleus  3 life stages:  Feeding stage: trophont/trophozoite  Reproductive stage: tomonts/tomites  Infective stage: trophozoites/tomites/theronts/swarmers

4. Geographic Distribution: It is wide spread in all freshwater fish but appears to be more common in aquarium fish, possibly due to the closer contact and stress involved with aquarium species. Definitive Hosts: All freshwater fish Intermediate Hosts: None

5. Life Cycle  Feeding stage: trophont/trophozoite  Attached to the epithelial cells and absorbs nutrients from the fish  Reproductive stage: tomonts/tomites  Quickly attaches to a substrate and encysts  Spends all of its energy rapidly multiplying  Infective stage: trophozoites/tomites/theronts/swarmers  Tomites have burst from cyst  Sprout cilia and immediate start looking for a host  Typically only have a few days to find a host or they perish

7. Sites of Infection  Skin  Eyes  Gills

8. Pathogenosis  Greyish/white pustules  Round or oval in shape  Roughly the size of a grain of salt  Epidermal cells produce mucous for protection  Death if not treated

9. Behavioral Signs  Wasting  Hiding abnormally  Rubbing against items  On skin:  White pustules  On eyes:  Cloudy/milky  On gills  Breathing at surface  Rapid breathing  White pustules

10. Diagnoses  Observation of fish  Study of pustules/parasite under microscope

11. Treatment  In aquarium fish:  Very dilute concentrations  Formaldehyde  Malachite green  Methylene blue  Commercial preparations

12. Control  Food with malachite green  Purchase healthy fish  Clean tank  Isolate sick fish