2. CHYTRID FUNGUS (AN OVERVIEW)
Fungi in the phylum Chytridiomycota are ubiquitous organisms that live in the water and soil.
They act as primary degraders using substrate such as chitin, plant detritus, and keratin.
Some are obligate parasites of fungi, algae, vascular plants rotifers, nematodes, or insects.

3. CHYTRID FUNGUS (AN OVERVIEW)
Batrachochytrium dendrobatidis -- a chytrid fungus pathogenic to amphibians
New genus and species original description published in March 1999 (Longcore et al., Mycologia 91(2): )
Isolated from captive blue poison dart frogs (Dendrobates azureus) at National Zoological Park
Earlier hypothesized to be cause of declines in Central America and Australia (Berger et al., 1998 Proc. Nat’l. Acad. Sci. 95: )

4. CHYTRID FUNGUS (AN OVERVIEW)
Tadpoles appear uneffected by the fungus which infects only the keratinised mouthparts.
Mechanisms by which cutaneous chytridomyccosis becomes a fatal infection
Cutaneous respiration and osmoregulation impared
Absorption of a toxic product produced by the fungus
Allows pathways for other pathogenic infections

5. CHYTRID FUNGUS (AN OVERVIEW)
In lab cultures sporangia developed fastest in 23º C (73.4 º F); slower growth occurred at 28 º C (82.4 º F); no growth observed at 29 º C (84.2 º F).
Experimentally infected frogs become terminally ill days after exposure.
Infection occurs through waterborne zoospores that invade the superficial layers of the epidermis

6. Species affected in the Southwest
Ambystomatidae
Ambystoma tigrinum stebbinsi
Hylidae
Acris crepitans
Hyla arenicolor
Bufonidae
Bufo boreas, B. canorus, B. microscaphus
Ranidae
Rana berlandieri, R. blairi, R. catesbeiana. R. chiricahuensis, R. subaquavocalis, R. tarahumarae, R. yavapaiensis

7. Rayleigh’s R = z = 17.03
n = 27 P <

8. Infected
Not Infected

9. Not infected

10. 20X

11. Infected
20X

12. Infected
zoosporangia
100X

13. Infected
zoosporangia
100X

18. Chytrid Fungus Management
Assume all aquatic sites to be infected with chytrid fungus
Long-term research sites should have a dedicated set of gear (clothing, nets, seines, etc.) used only at that site
ALL gear used at individual sites should be cleaned of mud and edebris and disinfected between sites using 10% bleach solution or quatra-ammonia solution

19. Chytrid Fungus Management
To reliably detect the presence of chytrid fungus at a site, a series of 3-5 tadpoles should be collected and preserved in 10% formalin.
These tadpoles should be provided to NMDGF or AGFD herpetologists and should be processed and examined histologically for the presence of chytrid fungus.
Federal and State permits are the responsibility of the collector or a representative of the sponsoring agency