Ecology and Phylogeny of Amphibian
Coccidia: A Review
Matthew G. Bolek, and Chris Whipps
Department of Zoology, Oklahoma State University,
and Environmental and Forest Biology
SUNY College of Environmental Science & Forestry
6,433 Extent Species of Amphibia
(Frost, 2009)
Anura
Caudata
Gymnophiona
Amphibian Coccidia
• Coccidia of frogs and toads, salamanders
and newts, and caecilians are the least
known of all the tetrapod vertebrate
classes.
Generalized Life Cycle of a Coccidian
2
3
1
Generalized Life Cycle of a Coccidian
1
Generalized Life Cycle of a Coccidian
2
Generalized Life Cycle of a Coccidian
3
The Frogs and Toads
(Anurans)
Anurans
• 5,679 extant species of frogs and toads in
395 genera and 47 families.
Anurans
• Of the 5,679 anuran species, only 1.2%
(67/5,679) of species in 7.6% (30/395) of
the genera and 30% (14/47) of the
families have ever been examined for
coccidia.
Anurans
• 19 species of Eimeria, 3 species of
Goussia, 1 species of Hyaloklossia and 9
species of Isospora have been described.
4X2
4X2
2X4
2X4
Anuran Coccidia World Distribution
8
8
7
4
3
*
Eimeria spp. of Anurans
Ovoidal
Irregular
Spherical
Variation in Oocyst Morphology
Stieda body
Oocyst Residium
Micropile Cap
Micropile
Variation in Endogenous Development
Extranuclear
Intranuclear
Bolek unpublished; Jirků and Modrý 2005
Variation in Sporulation
Exogenous
Endogenous
Bolek unpublished; Duszynski et al., 2007
Caudatans
• 580 extant species of salamanders and
newts in 64 genera and 9 families.
Caudatans
• Of the 580 caudatan species, only 7.7%
(45/580) of species in 28% (18/64) of the
genera and 67% (6/9) of the families have
ever been examined for coccidia.
Caudatans
• 20 Eimeria and 2 Isospora species have
been described from the 560 described
caudatan species.
Caudatan Coccidia World Distribution
13
6
3
20 Eimeria spp. of Caudata
Elliptical
Spherical
Micropile Cap
Gymnophionans
• 121 extant species of caecilians in 14
genera and 3 families.
Gymnophionans
• Only 1 Eimeria species has been described
from caecilians.
Eimeria dermophis Asmundsson, Campbell
and Duszynski, 2000
Ecology of Amphibian Coccidia
Ecology of Amphibian Coccidia
• Very little work has been done on the
ecology of amphibian coccidia (Duszynski,
Bolek and Upton 2007).
Ecology of Amphibian Coccidia
• Very little work has been done on the
ecology of amphibian coccidia (Duszynski,
Bolek and Upton 2007).
• Upton and McAllister, 1988; Upton et al.,
1993, suggested that amphibian coccidia are
rare, with low prevalence and few species of
hosts infected.
Recent Ecology Studies of Amphibian
Coccidia
• Bolek, et al., 2003; Jirků et al., 2009a, b
on Eimeria spp., Isospora spp., and
Goussia spp. in anurans and caudatans
from Europe and North America.
Ecology of Anuran Coccidia
• How do amphibians become infected with these
coccidia species?
• Examination of field collected tadpoles of western chorus frogs
indicated that they shed oocysts of Eimeria streckeri, Isospora
cogginsi and Isospora delicatus.
Prevalence of Isospora cogginsi, Eimeria streckeri
and Isospora delicatus in Adults, Tadpoles, and
Metamorphosed Western Chorus Frogs
N = 102
N = 44
N = 47
N = 45
80
Prevalence (%)
70
Isospora cogginsi
60
Eimeria strecheri
50
Isospora delicatus
40
30
20
10
0
March
April
June
Date
July
We collected western chorus frog eggs, brought
them into the laboratory, and reared tadpoles.
Experimental Infections
We exposed these tadpoles to coccidia
oocysts.
90% (18/20) of experimentally exposed tadpoles of western chorus
frogs shed oocysts of Isospora delicatus.
Tadpoles shed oocysts 9-10 days post exposure, and
continued shedding oocysts for 7 days, and did not
retain the infection before metamorphosis.
Sporulation: Exogenous.
Tadpole and metamorphosed frog digestive system.
European Eimeria ranae Jirků et
al, 2009
499 Frogs and Toads of 7 Species from 7 locations in the
Czech Republic.
3,703 Tadpoles of 7 Species from 7 locations in the Czech
Republic.
Only adults and tadpoles of the Common Frog and Agile
Frog were infected with Eimeria ranae.
Prevalence of Eimeria ranae in adults and
tadpoles of the Common and Agile Frog
from the Czech Republic
80
80
70
70
60
50
Prevalence
Prevalence
60
40
30
20
50
40
30
20
10
10
0
Adult
Tadpole
Life Stage
0
Adult
Tadpole
Life Stage
Exposed 6 species of Frogs and Toads to Eimeria
ranae.
Only adult and tadpoles of the Common and Agile
Frogs became infected with Eimeria ranae.
Cross infected adults and tadpoles of the Common
Frog and the Agile Frog with Eimeria ranae.
Other Anuran Coccidia
• Hyaloklossia liberkuehni infects tadpole and
metamorphosed anuran kidneys and survives
metamorphosis (Modrý et al., 2001).
Other Anuran Coccidia
• Goussia spp. only infect tadpoles and are lost
during metamorphosis, but sporulated oocysts
are found in the liver sinuses of
metamorphosed anurans (Jirků et al, 2009).
Ecology of Caudatan Coccidia
Salamander larvae feed on live prey in the open
water column and therefore few should be infected
with coccidia
N = 20
N = 19
N = 20
N = 14
100% (9/9) of metamorphosed tiger salamanders shed
oocysts of Eimeria ambystomae.
How Persistent are Amphibian
Coccidia Populations in Anuran and
Caudatan Hosts?
Eimeria fitchi
Prevalence (%)
Prevalence of Eimeria fitchi in Adult
Wood frogs from Wisconsin
100
90
80
70
60
50
40
30
20
10
0
N = 15
2003
1
N = 15
N = 17
2005
2
Year
2006
3
Prevalence of Eimeria ambystomae, and E.
urodela in larval Tiger Salamanders from
Nebraska
90
80
N = 39
N = 25
N = 20
Prevalence (%)
70
Eimeria ambystomae
60
Eimeria urodela
50
40
30
20
10
0
1
2004
2
2006
Year
3
2009
Phylogeny
• What is the relationship of amphibian
coccidia to coccidians of other animal
groups?
Amphibian Coccidia Phylogeny
• Jirků et al, 2009 recently sequenced the
partial SSU rDNA of Eimeria ranae,
Goussia noelleri, Goussia neglecta, and
Goussia sp. from European tadpoles and
frogs.
Jirků et al, 2009
Bayesian
Phylogenetic tree
as inferred from
partial SSU
rDNA sequences
North American Anuran Coccidia
Eimeria strecheri
Isospora cogginsi
Isospora delicatus
Conclusion
• Most species of amphibians have not been
examined for their coccidia species; their
ecology is poorly known.
Conclusion
• Most species of amphibians have not been examined for
their coccidia species; their ecology is poorly known.
• Goussia spp. exhibit stadial host specificity in
tadpoles, whereas Eimeria, Hyaloklossia and
Isospora species can infect larval and adult
amphibians.
Conclusion
• Most species of amphibians have not been examined for
their coccidia species; their ecology is poorly known.
• Goussia spp. exhibit stadial host specificity in tadpoles,
whereas Eimeria, Hyaloklossia and Isospora species can
infect larval and adult amphibians.
• Amphibian Goussia spp. and Eimeria spp. with
a stiedia body are basal among the Eimeridae;
whereas amphibian non stiedia body Isospora
spp. are more closely related to Hyaloklossia,
than stiedia body Isospora spp.
Acknowledgments
• R. S. Seville UW
• Miloslav Jirků (University of Vet &
Pharm Scie, Czech Republic)
• Dr. Armando Irizarry-Rovira (Eli Lilly
and Co.)
• Cedar Point Biological Station
• UNL, UNK, NIH BRIN, and Department
of Zoology OSU
Questions