Transcript Slide 1

HELMINTH COMMUNITY STRUCTURE IN SEVEN SPECIES OF TADPOLES FROM
NEBRASKA
Heather Tracy and Matthew Bolek, Department of Zoology, Oklahoma State University
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Figure 2. A) Rana catesbeiana, N = 28, B) Rana blairi, N = 47, C) Rana pipiens,
N = 40, D) Hyla chrysoscelis, N = 32, E) Pseudacris maculata, N = 15, F) Bufo
woodhousii, N = 85, G) Spea bombifrons, N = 10.
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Results
A total of 3,344 helminths of 6 species were recovered (Fig. 3).
The helminth compound community of tadpoles was dominated by
trematode metacercarial stages (N = 3,043), followed by adult nematodes
(N = 250), and juvenile nematodes and adult non-gravid trematodes (N =
44; Fig. 4).
Overall prevalence and mean species richness varied among the different
species of tadpoles, being highest for Rana catesbeiana and lowest for
Spea bombifrons (Fig. 4).
Ave. Species Richness +
1SD
Larval anurans, specifically tadpoles, are a group of hosts that have been
ignored in helminth community studies. Tadpoles differ from their adult anuran
counterparts in many ways, both ecologically and physiologically and therefore,
should differ in their helminth community structure from adult anurans. We
examined 257 tadpoles of 7 species during May-August 2008, form Nebraska for
helminth parasites. The helminth compound community of this larval
amphibian assemblage consisted of 6 species and was dominated with larval
trematodes. There was a high degree of helminth species overlap among
sympatric tadpole species, with only a single larval trematode, Glypthelmins
pennsylvaniensis, being restricted to a single tadpole species. Overall helminth
prevalence and mean species richness was highest in bullfrog tadpoles (Rana
catesbeiana) and lowest in the plains spadefoot toads (Spea bombifrons) and
this was related to time spent in the pond through metamorphosis being 104156 wks for bullfrog tadpoles and 2-3 wks for spadefoot tadpoles.
Overall Prevalence (%)
Abstract
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Figure 4. A) Overall prevalence of helminths recovered in 7
species of tadpoles. B) Average species richness in 7 species of
tadpoles.
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Conclusion
Figure 1: Frog life cycle. All temperate tadpoles are aquatic during
development, and contained into a single body of water. During this time
intestine length, mouth shape and body form changes. After
metamorphosis, adults are able to move about freely.
Materials and Methods
Seven species of tadpoles (Fig. 2) were collected from 5 different
locations in Eastern and Western Nebraska and examined for helminth
parasites.
Tadpoles were collected by dip-net brought back to the laboratory,
euthanized, and all organs including the musculature were examined,
and all parasites were identified as specifically as possible.
Standard measures of community structure were calculated.
Tadpole helminth communities are depauparate, and dominated
by generalist larval trematodes acquired through skin penetration.
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Figure 3. A) Gorgoderina attenuata, unencysted worm in kidney. B)
Gorgoderina attenuata removed from kidney. C) Echinostome metacercaria
in kidneys. D) Glypthelmins pennsylvaniensis unencysted metacercaria in
tissue and body cavity. E) Plagiorchiid metacercaria in tissue. F) Spyroxis
sp. encysted in stomach. G) Gyrinicola batrachiensis, large intestine. H)
Eggs of Gyrinicola batrachiensis.
Only 1 species was considered host specific, Glypthelmins
pennsylvaniensis.
Only 1 species was considered to have stadial specificity in
tadpoles, Gyrinicola batraciensis.
Acknowledgements
Thanks to Research Services Council and BRIN at the University of NebraskaKearney for funding this project, and also Morgan Tracy for helping with
tadpole collections.