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Arizona Game and Fish Department Biological Evaluation: Kanab Ambersnail July 1998 Page 3 C. BIOLOGY The reproductive biology and morphological descriptions of KASs are documented in Pilsbry (1948), Clarke (1991), Spamer and Bogan (1993), Stevens et al. (1997b), and the KAS Recovery Plan (USFWS 1995). KASs are hermaphroditic, possessing both male and female sex organs. Young snails develop from gelatinous egg masses attached to wet plant litter. Fully mature KASs are approximately 14 to 19 mm (0.5 to 0.75 inch) long and 7 to 9 mm (0.25 to 0.33 inch) in diameter. KAS shells are dextral (right-handed whorls), translucent, and amber-colored. Shells are characterized by a large, teardrop-shaped aperture and elongated first whorl, followed by two or three smaller, tapering whorls that form a pointed cone. Their bodies are light to dark brown and typically have an irregular-shaped pale spot within the back half of the first whorl. Their eyes are borne at ends of long peduncles (stalks), while tentacles are reduced to small protuberances at the base of the eye stalks. KASs have an approximately annual life cycle; they live 12-15 months (Clarke 1991). The surviving young and immature KASs enter into winter dormancy in October-November. They hibernate during winter months by attaching to bedrock or dry plant material with a mucous plug. Environmental cues (e. g., increased temperatures, extended photoperiod) in the spring, induce KAS emergence from hibernation and they begin to reproduce in the late spring and summer months. Peak reproduction typically occurs in the late summer, when densities of mature KASs are highest. As autumn approaches, the VP KAS population experiences a seasonal decline with mortality of mature individuals; as evidenced by hundreds of empty shells (Blinn et al. 1992, Stevens et al. 1997b). Taxonomic designation of KAS is currently based on anatomical description of the male genitalia and shell morphology. S.K. Wu (Univ. of Colorado, pers. corom. 1996) indicated that further review of the taxonomic status of KAS is necessary. KAS is a subspecies of Oxyloma haydeni, but it is recognized by the USFWS with full protection under the ESA. At VP and 3L, some mature KASs were found to be parasitized by the trematode flatworm Leucochloridium cyanocittae. Previous population data collected at VP indicates the frequency of Leucochloridium parasitism is low (< 10% of mature KAS observed between 1995-1997, Stevens et al. 1997b). Baer (1971) reported that the genus Leucochloridium may parasitize many species of passerine birds (definitive hosts), but always selects Succinea