1. Parasite Diversity, Ecology and Evolution Hsuan-Wien Chen Laboratory of Parasitism Dept. Biological Resources, National Chiayi University

2. Parasitology Parasitology studies Parasites & Parasitism
Who are parasites?
What are parasitism?

3. Parasite & Parasitism
Parasitism is a relationship in which one of the participants, the parasite, either harms its host or in some sense live at the expense of the host.

5. Who are parasites? Prokaryotes Eukaryotes Virus, bacteria… pathogens
Protist (unicellular organism)
i.e. Malaria (Plasmodium spp. 瘧原蟲)
Metazoan (true multicellular organism)
i.e. Schistosomiasis (Schistosoma spp. 血吸蟲)

6. Extant invertebrate species (crustacean, insect, arachnids…)
Helminth
(round worm, platyhelminth…)
~106,000 spp.
Mollusk
~110,000 spp.
Arthropods
(crustacean, insect, arachnids…)
~1,000,000 spp.
Includes 34 animal phyla , 1,300,000 spp.

7. Parasites consists more than 1/3 of
Lots parasites!
Platyhelminth
(flukes, cestodes…)
>80% parasitic
Arthropods
~40% parasitics
Roundworm
~50% parastic
Parasites consists more than 1/3 of
invertebrates (300,000~400,000 spp.)

8. How many parasites are there?
How to estimate?
Bt time
By host
By fauna
What is the magic number?
1M? 5M? 10M?

9. Mean# metazoan parasite spp. / shark sp. = 10.6 + 7.7 spp.
Caira 2005 in IPFC

10. Poulin & Morand 2000

11. Poulin & Morand 2000

12. Poulin & Morand 2000

13. The more you sampled the more parasites you get?
Freshwater fish
Sampling effect
The more you sampled the more parasites you get?
Marine fish
Poulin 2004

14. The longer you sampled the more parasites you get?
Accumulation effect
The longer you sampled the more parasites you get?
Poulin 2004

15. Photo by Oscar Pung
Parasites rule!

17. Parasites vs. Predation?
Parasites vs. Parasitoid?
Parasites vs. Brood parasitism?
Parasites vs. Pathogen/Disease?

18. Brood parasitism of robin nest - robin feeds a cuckoo chick

19. Parasites Endo- vs. Ecto-parasite Obligate vs. Facultative parasite
Accidental/Incidental parasite
Permanent vs. Temporary/Intermittent parasite
Micro- vs. Macroparasite

20. Vector vs. Parasite
Is mosquito a parasite?

21. Host Definitive/Final host Intermediate host Paratenic/ transport host
Host specificity
Reservoir host
Hyper-parasitism (supra-parasitism)

22. Life cycle of Anisakis simplex (海獸胃線蟲)
Audicana et al. 2002

23. The life cycle of parasites
Simple (direct) vs. Complex (indirect) life cycle

24. Why complex life cycle?
Why complex life cycle?
Advantage
Disadvantage

25. The life-cycle of Strongyloides ratti. 
The sex determination and larval development depends on environmental conditions

28. Sexually mature 2st larvae 1st larvae
What is missing in their work is to put the life cycle on the food web perspective, both topologically and then quantitatively, in ecological pyramid view… and one of subject that I am currently working at
1st larvae

29. Think…. Why become a parasite? Pro and Con…
Parasite as a disease and Parasite as a big chunk of biodiversity  Should we eradicate parasites?
How & Why complex life cycle evolve?

30. Host-Parasite Coevolution

31. Nit-picking is an ancient habit, as seen in (a) apes and in humans (b)

32. Human lice. (a) Head louse (Pediculus humanus)
Human lice. (a) Head louse (Pediculus humanus). (b) Nit (egg) of head louse. (c) Pubic louse or 'crab' (Pthirus pubis). 

34. Host-Parasite Coevolution

35. Host-Parasite Coevolution

36. The Mechanism of Host-Parasite Coevolution

37. Host-parasite co-evolution/phylogenes
Hafner, M.S. & Nadler, S.A. (1988) 

38. wing lice (Columbicola)
pigeon/dove hosts
wing lice (Columbicola)
Clayton et al. (2003).

39. TREEMAP3
Page, Roderic D. M., editor Tangled Trees: Phylogeny, Cospeciation, and Coevolution

40. Think…. Co-evolution vs. Co-speciation, what is the difference?
In the host-parasite system, who will evolve fast? Parasite or Host?
Can we use parasite as a proxy to reconstruct the history of host?