Parasites and salinity: costly tradeoffs in a threatened species |
| |
Authors: | David L Rogowski Craig A Stockwell |
| |
Institution: | (1) Department of Biological Sciences, North Dakota State University, Fargo, ND 58105-5517, USA;(2) Present address: Center for Aquatic Ecology and Conservation, Illinois Natural History Survey, 607 E. Peabody Dr., Champaign, IL 61820, USA |
| |
Abstract: | Parasites and environmental conditions can have direct and indirect effects on individuals. We explore the relationship between
salinity and parasites in an endemic New Mexico State threatened fish, the White Sands pupfish (Cyprinodon tularosa). Spatial variation in salinity limits the distribution of the endemic springsnail (Juturnia tularosae) within Salt Creek, a small desert stream. The springsnail is the presumed intermediate host for trematodes that infect the
White Sands pupfish, and trematode prevalence and intensity in pupfish are positively associated with the springsnail. Salinity
and parasites both have negative impacts on pupfish, but in areas of high salinity, pupfish can effectively escape parasites.
Pupfish trematodes were absent from sites lacking snails. At the upstream site, the absence of parasites and lower variance
in salinity were correlated with larger pupfish that were in better condition than pupfish at either the middle or lower sites.
Springsnails were present in the middle section, an area with moderate salinity, and all pupfish had trematodes (median abundance
847 trematodes/fish). Lipid levels and condition were lowest in fish from the middle site. Additionally, fewer older fish
indicated an increased mortality rate. At the lower site, springsnails were absent due to high salinity; pupfish trematode
abundance was much lower (six trematodes/fish), and fish condition was intermediate. An additional experiment revealed that
snail activity and survival were significantly reduced at high salinities commonly present at the lower site. Although both
high salinity and parasites significantly affect pupfish, parasites might be more detrimental. |
| |
Keywords: | Salinity Trematodes Cyprinodon tularosa Juturnia tularosae Lipids |
本文献已被 PubMed SpringerLink 等数据库收录! |
|