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<br />Arizona Game and Fish Department <br />NGTR 125: Kanab Ambersnail Report <br /> <br />April 1998 <br />Page 6 <br /> <br />Preliminary papulation estimates, derived from bootstrap statistics, show an increased number of <br />KASs since the March 1996 flood. The estimated number of KASs below the 45,000 cfs stage <br />dropped from 2126 in March 1996 to 420 in April 1996 (Stevens oet al. 1997a). Preliminary <br />estimates ofKAS in the low zone for 1997: 245 in March, 4070 in May, and 2571 in August (1... <br />Stevens, pen. comm.). October estimates are still being analyzed (V. Meretsky, pers. comm.). <br /> <br />Deer mice (Peromyscus monicukJtus and P. crinitus), suspected KAS predators at VP, were live- <br />trappetlto estimate densities and distribution of rodents. Trapping success for each survey month <br />in 1997 is summarized: March (two trap-nights combined = 11.5%, 9 mice); May (13.6%, 3 <br />mice); August (8.3c){', 2 mice); and October (4.1 C){" 2 mice). All mice trapped in 1997 were P. <br />crinirus, although one immature P. maniculatus was observed in October (1... Stevens, pen. <br />comm.). <br /> <br />In August, four KASs were found to be parasitized by the trematode LeucochJoridium cyarwcittae; <br />these were the only reported occurances during the 1997 season. First discovered in August 1995, <br />this ~te had infested eight mature (> 13 nun size) KASs that year (Stevens et aI. 1997b). Only <br />one KAS was found parasitized in 1996, during the May monitoring survey (Stevens et aI. 1997a). <br /> <br />New observations on parasitized KASs indicate that sporocysts withdraw into the snail's body <br />cavity and shell during noctumal periods, and actively pulsate up into the eye stalks when exposed <br />to natural or artificial light. Macrophotos and closeup video of two parasitized KASs with <br />pulsating sporocysts were made by AGFD audio-visual technicians. Parasitized KASs are capable <br />of producing egg masses. One egg mass of 10 eggs was found on wet litter within the first 48 <br />hours of captivity, and the second egg mass, containing 5 eggs, appeared in the next 24 hours. <br />Both parasitized KASs and egg masses were preserved as voucher specimens. Anatomical <br />dissection of one specimen (IS mm size) with two sporocysts revealed no changes to its <br />reproductive tract other than it had been pushed aside by the sporocysts (J. Hoffman, pen. <br />comm.). Both sporocysts were 12 nun long and 2 mm wide, and occupied 80C){, of the snail's <br />head. One sporocyst was dissected and found to contain 97 cercaria (J. Hoffman, pen. comm.). <br /> <br />HABITAT SUll.vEYS <br />Between July and October 1997, we visited 19 sites in the Grand Canyon region and northern <br />Arizona-17 new surveys and 2 seasonal revisits from previous surveys. Indian Gardens and Santa <br />Maria Springs were revisited to determine seasonal changes in environmental conditions, flora, <br />fauna, and recreation use. Site summaries for the 17 new survey sites are provided in Appendix <br />A. Habitat suitability for 74 evaIuated sites are listed in Tables 3 and 4. Optimum and more <br />desirable KAS establishment sites in Gzand Canyon are mapped in Figure 1. Three new sites were <br />evaluated as "more desirable" KAS habitat; one located within Grand Canyon National Park <br />(Dripping Spring) and two on the Hualapai Reservation (Travertine Falls and Bridge Canyon <br />Creek). No additional KAS populations were found, but new occurrences of other mollusk species <br />were recorded. <br />