1. Parasitism in Freshwater Fish Jonathan King

2. Numerous types of parasites Protozoans Trematodes Nematodes Cestodes Crustaceans Leeches

3. Protozoa Ciliates –Large protozoa up to 2mm in length that have cilia (hair like organelles) covering their body at some point, if not all, of their life cycle Flagellates –Protozoa equipped with one or more whip-like flagella used for propulsion

4. Ciliates Largest group of protozoa Direct life cycle Common in pond-reared fish Easy to eliminate in aquarium due to controlled conditions Easily transmitted…nets, hoses or hands

5. Ciliates cont. Symptoms include –Skin or gill irritation Rubbing and abnormal breathing Species –Ichthyophthirius multifiliis –Tetrahymena –Apiosoma –Epistylis

6. Ichthyophthirius multifiliis Disease –Ich or white spot disease –Responsible for majority of fish fatalities Symptoms –Small lesions on body or fins –If gills only…no lesions but a thick mucus Size –1000um diameter

7. Ichthyophthirius multifiliis cont. Identification –Horseshoe shaped macronucleus Possible mis-ID –Immature forms may resemble Tetrahymena

8. Ichthyophthirius multifiliis

9. Ichthyophthirius multifiliis cont. Life cycle –Theronts infect fish t=0 Dig under scales or gills –Mature trophozoites leave fish t=~7days Settle and secrete cyst –Cysts rapidly divides to produce hundreds of tomites –At maturity they leave cysts looking for host –Whole cycle =10 days to 4 weeks (temp)

10. Ich Treatment Life cycle is temp dependent –So raising the temp increases life cycle to days instead of weeks Formalin Chelated copper Copper sulfate Treat for >3days after last spot gone

11. Any last thoughts on Ich Well you can vaccum the floor of tank to get the cysts?...not extremely effective but buys time If diagnosed early –Treatments may be effective If infestation in advanced stages –Fish may be immune –Toilet

12. Tetrahymena Donde esta tetrahymena? –Living in organic debris –Body surface of your favorite fish Treatment –Same as Ich –If internal …like the eyes toilet

13. Tetrahymena

14. Apiosoma Location –Gills, skin, or fins What does he look like? –Vase like –Oral cilia Treatment –Very treatable…formaline, copper sulfate..etc

15. Apiosoma

16. Epistylis Stalked ciliate very similar to apiosoma Danger –Greater concern than most due to proteolytic enzymes secreted by the organism –The enzyme breaks down proteins in the skin of the fish making the fish susceptible to bacterial infection

17. Epistylis Treatment –Salt.02% salt solution for extended period 3% salt dip –More than one treatment required

18. Flagellates External and internal High magnification –200-400x species –Spironucleus –Ichthyobodo –Myxozoa –Microsporidia

19. Spironucleus Location –Intestinal tract Symptoms –Extreme weight loss –Distended abdomen –Yellow mucoid build up in intestines

20. Spironucleus Diagnosis –Intestinal prep @ 200-400x –High counts…too many to miss Treatment –Metronidazole bath 5mg/L Every other day…one week

21. Ichthyobodo External Flagellate Large amounts of mucus –Blue slime disease in catfish Location –Gills, skin and fins Diagnosis –Microscopic examination…. Treatment…formalin, copper sulfate..etc

22. Myxozoa Widespread in native or pond reared fish How bad is it? –Most infections not bad –But some may be serious…young fish

23. Myxozoa Extremely abundant and diverse Speciation –Based on spore shape and size Examination technique –Preps of infected area –Histologic sections of tissue

24. Myxozoa cont Symptoms –Vary depending on the organ affected Excess mucus productions White or yellowish noduleson target organs Diseases –Whirling disease- salmon –Wasting disease

25. Myxozoa Treatment –Toilet –No remedies known –Spores can survive >1year Disinfection necessary after removal of infected fish

26. Microsporidia Intracellular parasites –Require host tissue for reproduction Mode of transmission –Ingesting spores from infected fish or food Symptoms –Small “tumors” in various tissues –Enlargement of hosts cells cause tumor like masses

27. Microsporidia Clinical signs –Dependent on tissue infected –{from no lesions to dead} –Serious cases…cysts enlarge to a point that organs no longer function correctly

28. Microsporidia Infections caused –Pleistophora Infects skeletal muscle Cysts  Treatments –None available –Spores tough Can survive long periods Most environmental conditions it can handle

29. Microsporidia So what am I supposed to do? –Flushing of infected fish –Disinfect the environment

30. Conclusion Poor water quality, crowding, stress and diet issues are main issues with fish susceptibility to parasitism So if you have concerns on water quality issues…prevent it.

31. References "Ichthyophthirius multifiliis." Wikipedia, The Free Encyclopedia. 15 Nov 2007, 04:17 UTC. Wikimedia Foundation, Inc. 15 Nov 2007.http://en.wikipedia.org/w/index.php?title=Ichthyophthiriu s_multifiliis&oldid=171595742 edis.ifas.ufl.edu www.microscope-microscope.org www.aquaticparadise.com www.uoguelph.ca. www.koisite.be www.ars.usda.gov http://edis.ifas.ufl.edu/pdffiles/FA/FA04100.pdf