1. Distribution of the swimbladder parasite Anguillicola crassus in American eels in the Northeastern Atlantic University of Massachusetts Dartmouth Department of Biology Amy Aieta & Kenneth Oliveira

2. Life History of Anguilla rostrata Silver phase Egg Leptocephalus larvae Glass eel/Elver Yellow phase

3. L2 Released Intermediate Host L2 molts to L3 Intermediate/ Paratenic Host Ingested by Eel L3-L4 swimbladder wall L4-L5 swimbladder lumen The life cycle of Anguillicola crassus

4. Biogeography of Anguillicola crassus Identified in Southeast Asia 1974 (Anguilla japonica) Early 1980s introduced to Europe (Anguilla anguilla) 1995 found in North America (Anguilla rostrata)

5. Occurrence of A. crassus in North America 1995 Texas ( TPWD; Moravec) South Carolina ( Fries et al. 1996) Chesapeake Bay ( Barse and Secor 1999; Barse et al. 2001) Hudson River ( Barse and Secor 1999) 2003 N. Dartmouth, MA

6. Objectives 1)Determine northern extent of parasite range in USA 2) Examine prevalence & intensity within NE 3) Examine effects of parasite/eel interactions

7. Methods Northeastern Distribution Yellow eels * Summer 2005 Southern Sampling Survey CT, RI, S.-MA Northern Sampling N.-Ma, NH, ME n=13 n=10 n=3

8. Collection of Yellow Eels in Freshwater

9. Collection of Silver Eels

10. Eels euthanized w/Clove oil Weighed/length measured Parasites counted Parasite length measured Preliminary Analysis

11. Analysis Prevalence Example 30% infected Mean Intensity 1.67 parasites

12. Results

13. 69% 35% 28% Prevalence of Infection: Rhode Island N. KINGSTON

14. 7% 33% 62% 76% 16% 52% 21% 58% 64% 33% Prevalence of Infection: Massachusetts NEW BEDFORD PLYMOUTH BOSTON

15. 0% 31% 0% Prevalence of Infection: Maine BANGOR PORTLAND 0% 26% 35%60% 58% 65% 53% Kennebec River Estuarine eels

16. n = 315

18. Silver Eel Data: Paskamansett River Year PrevalenceMean Intensity 200328%2.9 2004*52%5.8 2005?? Significance Prevalence: Fischer's Exact Test p =.008 Intensity: T-test p =.007

19. Conclusions Current Northern Limit Sedgeunkedunk Stream, ME 44°45.306N, tributary of the Penobscot River No latitudinal trend Possible ballast water introduction Temperature: not an apparent limiting factor Influences of Parasite All size classes infected No apparent detrimental effects on eel weight/length Suspected negative impact on migrating silver eels

20. Questions/Discussion