1. TEMPLATE DESIGN © 2008
www.PosterPresentations.com
Abstract
Results and Discussion
Conclusion
References
Background
Methods
1. Of the 83 dissected river otter intestines 60 were infected with parasites and the
remaining 23 were not infected.
2. Echinostoma spp., Acanthocephala spp., Nematode spp., and Cestode spp. are
of the known parasites found in the different counties.
3. From the 60 infected intestines, 33 of these were males and 27 were female.
The data shows that 76.7% (33/43) of males were infected and 67.5%(27/40)
females. This suggests that the males have a higher infection percentage,
based off this survey sample.
4. The data shows there is no evidence to suggest that there is a significant
difference in the existence of all parasites between the four regions (NE, SE,
NW, SW,) in Wisconsin with the exception of Echinostoma spp. which has a
lower incidence in the SE region.
a) b) c)
Pab1
p
Pub1p
Dcp2p
eIF4G
Pat1p Sbp1p
River otters (Lontra canadensis) are a species of interest for the Wisconsin DNR
due to fluctuations in population size. The Wisconsin DNR collects carcasses of
legally harvested otters trapped throughout the season and then makes them
available for research studies. On February 14th, 2013 our laboratory obtained
100 intestines to examine for parasites. The intestines were then dissected and
the digested material was separated through sieves of different sizes. The
digested material was then examined microscopically and any parasites that were
collected were stored in 70% ethanol. Some parasites were stained for further
identification. With additional data supplied by the Wisconsin DNR, conclusions
were made about the prevalence and intensity of parasites and their impact on
the river otter population. All 100 intestines have been examined, but data was
analyzed based upon 83 intestines, which had complete records. It was found that
72.3% (60/83) of the intestines were infected with parasites, with an average
intensity of 31(1-620, range) parasites.
The North American river otter (Lontra canadensis) is a mammal that preys
predominantly on fish and crayfish, although other aquatic species also contribute
to their diet. River otters can be found throughout the state of Wisconsin.
Acknowledgements
We would like to thank the Wisconsin DNR, Erika Vail, Dr. Brant Deppa, and Dr.
Kimberly Bates for their resources and contributions to our research. We would also
like to thank the students who contributed to this research in years past.
Gastrointestinal Parasites of Wisconsin River Otters (Lontra canadensis)
Ashley Wiederin, Johnna Miller, Kelsie Kovac, Lucas Seaberg, Nadia Nassif, Shaylee Larson, Kaitlyn Dreher, Samantha Christiansen, Girma Kenea, Chelsey Otto, and
Mohamed Warsame
Dr. Kimberly Bates and Kelsey Hoffmann
Biology Department. Winona State University, Winona, MN 55987
Otter intestines were cut open and digested
material was rinsed out through four sieves
ranging in pore size diameter. Digested material
was examined for parasites under a dissecting
microscope. Parasites found were removed,
cleaned, and placed into labeled vials containing
70% EtOH for preservation.
Echinostoma are a genus of trematode whose first intermediate hosts are
typically snails. Otters become the definitive host when they consume the
second intermediate host which is typically mussels or fish. Acanthocephala are
parasitic worms that attach to the digestive tract by an anterior, spiny, retractile
proboscis. Otters become the definitive host when they consume an infected
intermediate host which is typically crustaceans.
Prevalence represents the proportion of individual otters that are infected with a
specific parasite type (table 2).
The mean intensity defines the number of each species of parasite found per
infected otter (Table 3).
After examination of 100 river otter intestines, data was analyzed based upon 83
intestines, which had complete records. Of the 83 intestines, 60 were infected
with parasites and 23 had no parasites present. Of the parasites collected and
identified, several variables were used for comparison. Among these were
region, gender, parasite prevalence, and parasite type. These variables were
used for correlation of parasites and the river otter population. Positive
identification could be made for four different types of parasitic infection.
Of the 83 river otter intestines analyzed, 60 were infected with parasites. Males
accounted for 33 of those infected while females accounted for the remaining 27.
Of the 23 non-infected river otter intestines,10 were from males and 13 were from
females (Figure 8).
1. Acanthocephaliasis: DPDx - Laboratory Identification of Parasitic Diseases of Public Health Concern. (2013, November
29). Retrieved March 17, 2015, from http://www.cdc.gov/dpdx/acanthocephaliasis/index.html
2. "Echinostoma." Center for Disease Control. Center for Disease Conrol, 28 11 2013. Web. 31 Mar 2014.
<http://www.cdc.gov/dpdx/echinostomiasis/index.html>.
3. North American River Otter - National Wildlife Federation. (n.d.). Retrieved March 16, 2015, from
http://www.nwf.org/wildlife/wildlife-library/mammals/north-american-river-otter.aspx
4. Ramel, G. (2001, January 1). The Phylum Acanthocephala. Retrieved March 17, 2015, from
http://www.earthlife.net/inverts/acanthocephala.html
5. Shapiro, L. (2014, January 1). Descriptions and articles about Echinostoma. Retrieved March 17, 2015, from
http://eol.org/pages/61251/details
6. Wisconsin Department of Natural Resources. (n.d.). Retrieved March 15, 2015, from
http://dnr.wi.gov/topic/WildlifeHabitat/Furbearers.html
Figure 1: Counties within the state
of Wisconsin
Table 1: Number of Otter Intestines
Harvested by County Figure 6 : SEM photos of
Acanthocephala spp. (left) and
Echinostoma spp. (right)
Female otters had a higher mean intensity for all parasites except for Tapeworm
spp., which was higher in males, and Nematode spp., which had the same mean
intensity for both males and females (figure 10).
Figure 7: Dissecting microscope images of (in order from left to right): Acanthocephala
spp., Cestode spp., Echinostoma spp., and Nematode spp. found in WI River Otters
collected in 2012-2013
Figure 8: Number of River Otter Intestines of which were Infected versus Not
Infected in Males and Female River Otters Harvested in WI, 2012-2013
Figure 10: Mean Parasitic Intensity of Echinostoma spp., Acanthocephala
spp., Nematode spp., Tapeworm spp., and Unknown Parasites in Male and
Female River Otters Harvested in WI, 2012-2013
Table 2: Prevalence of Parasitic infection (by type) in River Otters
collected from WI DNR in 2012-2013
Table 3: Mean Intensity of Parasitic infection (by type) in River
Otters collected from WI DNA in 2012-2013
Average intensity of each type of parasitic infection was separated by the 4
regions of Wisconsin. Overall, there was a lesser number of otters collected from
the northern regions of Wisconsin (figure 11), however, they still presented with a
higher mean intensity of parasitic load than the otters collected from the southern
regions. The error bars show that there is no evidence to suggest that there is a
significant difference in the existence of parasites between the four regions with
the exception of Echinostoma spp. which has a lower incidence in the SE region
(figure 12).
Figure 3: Lifecycle of Acanthocephala.Figure 2: Lifecycle of Echinostoma.
Figure 4: Echinostoma found in Wisconsin River Otter
Feces harvested in WI, 2012-2013
Some parasites were stained using
various staining protocols to help with the
identification process. Some parasites
were gold sputtered then examined with a
scanning electron microscope (SEM).
Pictures were taken and will be used to
help with further identification.
Figure 11: Number of River Otter Intestines of which were Infected versus Not
Infected in the 4 Regions of WI (NW, SW, NE, SE) in 2012-2013
Nematode spp. and Cestode spp. were also found in the river otter intestines
harvested from Wisconsin. These phyla of parasites commonly inhabit the
digestive tract of vertebrates.
Figure 5: Echinostoma Ventral Sucker Stained with
Borax-carmine and Aniline Blue
Figure 12: Average Parasitic Intensity of Acanthocephala spp., Echninostoma
spp., Nematode spp., Tapeworms spp., and Unknown Parasites in River
Otters Separated by the 4 Regions of Wisconsin, (NW, SW, NE, SE)
Harvested in 2012-2013
-10
0
10
20
30
40
50
60
NE NW SE SW
MeanIntensityofParasiticLoad
4 Regions in Wisconsin
Acanthocephala
Echinostoma
Tapeworm
Nematode
Unknown
11
27
1
7 6
4
24
1 6
0
10
20
30
40
50
60
Acanthocephala Echinostoma Tapeworm Nematode Unknown
NumberofInfectedOtters
Parasite Type
Males Females
Figure 9: Number of River Otters Infected with Acanthocephala spp.,
Echninostoma spp., Nematode spp.,Tapeworms spp., and Unknown
Parasites by sex of River Otters Harvested in WI, 2012-2013
-10
0
10
20
30
40
50
60
MeanParasiticIntensity
Parasite type
Males
Females
NW
NE
SW
SE
Male and female infected otters were further separated by type of parasitic
infection. More male otters were infected with every parasite type except for the
unknown species where the same number of males and females were infected.