Laserfiche WebLink
<br /> <br /> <br />50 <br /> <br /> <br />GREAT BASIN NATURALIST MEMOIRS <br /> <br />No.3 <br /> <br /> <br />lake Mead <br /> <br /><l <br />o <br />~ <br />lLI <br />2: <br /> <br />23July <br /> <br />UTAH <br />ARIZONA <br /> <br />Fig. 8. Dates of the first appearance of woundfin fry at various locations along the mainstream Virgin River dur- <br />ing summer 1977. Collections were made at all locations indicated at one- to two-week intervals until fry were <br />taken. <br /> <br />1946). While col!ections of C. baileyi made <br />during 1963 showed an increased incidence <br />of parasitism by Lernea, the fish population <br />remained abundant and the incidence of par- <br />asitism declined (Fig. 10). In addition, there <br />was a 5 percent incidence of parasitism in <br />1959 prior to introduction of mollies. Per- <br />haps the several spring sources in the head- <br /> <br />TABLE 3. Incidence of parasitism by Lemea on Crenichthys baileyi. N = number examined. % = percent with <br />one or more Learnea attached. <br /> 1938 1940 1941 1947 1948 1949 1950 <br />Location N % N % N % N % N % N % N % <br />Headwaters of <br />Moapa River 250 0 7 0 27 0 28 0 158 0 11 0 11 0 <br />Ash Spring 5 0 8 0 106 0 64 0 <br />Crystal Spring 20 0 64 0 83 0 <br />Hiko Spring 1576 0 6 0 54 0 52 0 <br />Mormon Spring <br />Preston Town Spring 58 0 <br />Preston Big Spring 17 0 <br /> <br />shortfin molly (Poecilia mexicana) was in- <br />troduced in the spring of 1963 (local testi- <br />mony). No mollies were taken in collections <br />made in March 1963, but they were present <br />in collections made on 12 October 1963 <br />(Deacon et al. 1964). In addition, the mosqui- <br />tofish (GambuSia affinis) had been present in <br />the area since before 1938 (Miller and Alcorn <br />