56(2): 171–175 Conservation perspectives for the 9-spine stickleback (Omono type) in spring-fed habitats of Akita and Yamagata Prefectures Pungitius sp. (Omono type) 1987; Takata et al., 1987 2003 2007 IA 2002 2003 IA (2003) 60 mm 9 2002 20 mm 1 33 8 1 Takahashi and Goto, 2001; 2003 2005 (1,832 m2 ) (959 m2 ) (1,827 m2 ) 3 1998 3 1938 2 1986 Series 1 S 3 8 5 6 1 2 30 cm 30 cm 5 cm 1995; 2006 1 9.6