| Abstract: | Water in the Little Colorado River within Grand Canyon is naturally high in salt (NaCl), which is known to prohibit development of external fish parasites such as Ich (Ichthyophthirius multifiliis). The naturally high salinity (>0.3%) of the Little Colorado River at baseflow may be one factor allowing survival and persistence of larval and juvenile humpback chub (Gila cypha) and other native fishes in Grand Canyon. We compared salinity readings from the Little Colorado River to those reported in the literature as being effective at removing protozoan parasites from fish. In laboratory tests, 10 juvenile roundtail chub (Gila robusta; 61–90 mm TL) were randomly placed into each of 12, 37-L aquaria filled with freshwater, water obtained from the Little Colorado River (0.3% salinity), or freshwater with table salt added until the salinity reached 0.3%. Roundtail chub was used as a surrogate for humpback chub in this study because the species is not listed as endangered but is morphologically and ecologically similar to humpback chub. All roundtail chub infected with Ich recovered and survived when placed in water from the Little Colorado River or water with 0.3% salinity, but all experimental fish placed in freshwater died because of Ich infection. The naturally high salinity of the Little Colorado River at baseflow (0.22%–0.36%), appears sufficiently high to interrupt the life cycle of Ich and may allow increased survival of larval and juvenile humpback chub relative to other areas within Grand Canyon. |
| Genre: | Article |
| ProdID: | 70040717 |
| Citation Author: | Ward, David L. |
| Citation Contributing Office: | Southwest Biological Science Center |
| Citation Datum: | |
| Citation Day: | |
| Citation Edition: | |
| Citation Editor: | |
| Citation End Page: | 338 |
| Citation Issue: | 3 |
| Citation Keywords: | |
| Citation Language: | English |
| Citation Larger Work Title: | Western North American Naturalist |
| Citation LatN: | 36.5318 |
| Citation LatS: | 35.6882 |
| Citation LonE: | -111.828 |
| Citation LonW: | -114.0572 |
| Citation Month: | |
| Citation No Pagination: | |
| Citation Number Of Pages: | |
| Citation Online Only Flag: | |
| Citation Phsyical Description: | 5 p. |
| Citation Projection: | |
| Citation Public Comments: | |
| Citation Publisher: | Brigham Young University |
| Citation Series: | |
| Citation Series Code: | |
| Citation Series Number: | |
| Citation Search Results Text: | Salinity of the Little Colorado River in Grand Canyon confers anti-parasitic properties on a native fish; 2012; Article; Journal; Western North American Naturalist; Ward, David L. |
| Citation Start Page: | 334 |
| Citation Volume: | 72 |
| Citation Year: | 2012 |
| Type: | citation/reference |
| Text: | Salinity of the Little Colorado River in Grand Canyon confers anti-parasitic properties on a native fish; 2012; Article; Journal; Western North American Naturalist; Ward, David L. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| URL (INDEX PAGE): | https://ojs.lib.byu.edu/wnan/index.php/wnan/article/viewArticle/3886 |
| Date Other: | Wed, 14 Nov 2012 00:00 -0600 |
| Publisher: | Brigham Young University |
