| Abstract: | Lahontan cutthroat trout Oncorhynchus clarki henshawi were sensitive to simulated solar ultraviolet-B radiation (UVB) and exhibited grossly visible signs of sunburn upon exposure. Razorback suckers Xyrauchen texanus, however, were tolerant to simulated solar UVB and showed no grossly visible signs of exposure. Cutthroat trout also had considerably less of an unidentified, possibly photoprotective, substance in the skin than did razorback suckers. In all attempt to characterize the cellular response to simulated solar UVB exposure in the skin of these two species, we examined sections from UVB-exposed fish by light and electron microscopy. Cutthroat trout showed grossly visible signs of sunburn by 48 h. Histologic observations included a sloughing of the mucous cells, necrosis and edema in the epidermis and dermis, and, in some cases, secondary fungal infections. Razorback suckers did not show any visible signs of sunburn during 72 h of experimental exposure. Histologic analyses revealed that cell necrosis had occurred, but the severe necrosis and sloughing noted in cutthroat trout was not observed. An increase in epidermal thickness, apparently due to hypertrophy and hyperplasia of large PAS-negative cells, occurred in the razorback suckers. These cells contained a large central region of low electron density and appeared to be club cells. In some, extensive interdigitation of the electron-lucent cytoplasm with adjacent epithelial cell margins occurred. Near the surface of the epidermis these cells were larger and the interface with epithelial cells lacked complex interdigitation. These cells may contain the substance that appears to protect razorback suckers against UV-B radiation. |
| Genre: | Article |
| ProdID: | 70019848 |
| Citation Author: | Blazer, V. S.; Fabacher, D. L.; Little, E. E.; Ewing, M. S.; Kocan, K. M. |
| Citation Contributing Office: | |
| Citation Datum: | |
| Citation Day: | |
| Citation Edition: | |
| Citation Editor: | |
| Citation End Page: | 143 |
| Citation Issue: | 2 |
| Citation Keywords: | |
| Citation Language: | English |
| Citation Larger Work Title: | Journal of Aquatic Animal Health |
| Citation LatN: | |
| Citation LatS: | |
| Citation LonE: | |
| Citation LonW: | |
| Citation Month: | |
| Citation No Pagination: | |
| Citation Number Of Pages: | 12 |
| Citation Online Only Flag: | |
| Citation Phsyical Description: | |
| Citation Projection: | |
| Citation Public Comments: | |
| Citation Publisher: | |
| Citation Series: | |
| Citation Series Code: | |
| Citation Series Number: | |
| Citation Search Results Text: | Effects of ultraviolet-B radiation on fish: Histologic comparison of a UVB-sensitive and a UVB-tolerant species; 1997; Article; Journal; Journal of Aquatic Animal Health; Blazer, V. S.; Fabacher, D. L.; Little, E. E.; Ewing, M. S.; Kocan, K. M. |
| Citation Start Page: | 132 |
| Citation Volume: | 9 |
| Citation Year: | 1997 |
| Type: | citation/reference |
| Text: | Effects of ultraviolet-B radiation on fish: Histologic comparison of a UVB-sensitive and a UVB-tolerant species; 1997; Article; Journal; Journal of Aquatic Animal Health; Blazer, V. S.; Fabacher, D. L.; Little, E. E.; Ewing, M. S.; Kocan, K. M. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| Date Other: | Wed, 1 Jan 1997 00:00 -0600 |
| Publisher: | |
