Ultraviolet radiation has far-reaching effects in marine ecosystems, but many marine organisms have UV-absorbing compounds that protect them from sun-induced damage. The mucus of coral reef fish has been found to contain mycosporine-like amino acids that absorb UV light from 309-360 nm. Using UV spectrophotometry, we examined whether fish are able to allocate these MAA sunscreen compounds to areas of the body that receive the most UV radiation. We compared absorbance spectra of mucus from the body surface of dorsal, ventral, caudal and head areas in two species of Scaridae (Scarus schlegeli and Chlorurus sordidus) from Coral Bay, Western Australia. All fish analyzed showed signs of MAAs, and results suggested that fish can increase UV absorbance in mucus over the dorsal area, which receives the brunt of UV radiation. Less radiation was found in mucus from the ventral area, which receives the least radiation. We also analyzed integrated absorbance and standard length and found a relationship in C. sordidus. Significance was not found between standard length and integrated absorbance, indicating the need for further study. Overall, results suggest that fish are highly responsive to UV levels in relation to mucus secretion and that MAAs may be ecologically expensive to acquire and utilize.
Environmental Sciences | Oceanography
Cerny-Chipman, Elizabeth, "Distribution of Ultraviolet-Absorbing Sunscreen Compounds Across the Body Surface of Two Species of Scaridae" (2007). Independent Study Project (ISP) Collection. 147.