The role of the egg jelly coat in protecting Hyla regilla and Bufo canorus embryos from ultraviolet B radiation during development.
BACKGROUND
Previous studies have suggested that Ultraviolet B (UVB) radiation may play a role in amphibian population declines. Some of these studies also indicate that egg hatching success is unaltered in some species of anurans as a result of UVB exposure. It has been proposed that the egg mass jelly provides photoprotection to the developing embryos.


METHODS
Direct spectrophotometric scans of egg jelly, scans of egg jelly methanol extracts, and experimental manipulation in a solar simulator during development were all used to assess the role of egg mass jelly as a photoprotective agent.


CONCLUSIONS
For Hyla regilla, scans of egg jelly and methanolic extracts (for mycosporine-like amino acid content) both displayed no absorption in the UV range. Experimental manipulation (removal of egg mass jelly) with both Hyla regilla and Bufo canorus egg masses in a solar simulator demonstrated that egg mass jelly played no apparent role in photoprotection of either of these species.


CONCLUSIONS
Based on the results in this study it seems unlikely that the egg jelly coat is playing a crucial role in protecting developing embryos from the impact of UVB radiation.
Hansen
Lara J
LJ
Section of Evolution and Ecology, University of California, Davis, California 95616, USA. lara.hansen@wwfus.org
Fabacher
David L
DL
Calfee
Robin
R
D000042:Absorption / Q000528:radiation effects; D000818:Animals; D001001:Anura / Q000196:embryology* / Q000254:growth & development; D002025:Bufonidae / Q000196:embryology / Q000254:growth & development; D004781:Environmental Exposure; D007814:Larva / Q000254:growth & development / Q000528:radiation effects; D008954:Models, Biological; D010063:Ovum / Q000254:growth & development / Q000528:radiation effects*; D011157:Population Dynamics; D011836:Radiation Tolerance; D013053:Spectrophotometry; D013472:Sunlight / Q000009:adverse effects; D016019:Survival Analysis; D014466:Ultraviolet Rays / Q000009:adverse effects*