Ecology and Phylogeny of Amphibian Coccidia: A Review

Matthew G. Bolek, and Chris WhippsDepartment 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

1

2

3

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.

• 19 species of Eimeria, 3 species of Goussia, 1 species of Hyaloklossia and 9 species of Isospora have been described.

Anurans

4 X 2 4 X 2 2 X 4 2 X 4

Anuran Coccidia World Distribution

8 8

4

7

3*

Eimeria spp. of Anurans

Ovoidal Irregular Spherical

Variation in Oocyst Morphology

Stieda body Oocyst Residium Micropile Cap Micropile

Variation in Endogenous Development

Bolek unpublished; Jirků and Modrý 2005

Extranuclear Intranuclear

Variation in Sporulation

Bolek unpublished; Duszynski et al., 2007

Exogenous Endogenous

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.

• Only 1 Eimeria species has been described from caecilians.

Gymnophionans

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

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

0

10

20

30

40

50

60

70

80

Adult Tadpole

Life StageP

rev

ale

nce

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 of Eimeria fitchi in Adult Wood frogs from Wisconsin

2003 2005 2006Year

N = 15 N = 15 N = 17

Prevalence of Eimeria ambystomae, and E. urodela in larval Tiger Salamanders from

Nebraska

2004 2006 2009Year

N = 39 N = 25 N = 20

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

Sarcocy

stidae

Eimeri

dae

Sarcocy

stidae

Eimeri

dae

Sarcocy

stidae

Eimeri

dae

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