EN
The river lamprey caught in Lake Dabie in the autumn seasons of 1997 (35 individuals) and 1998 (53 individuals) had mean individual weights of 145.1 and 139.3 g, respectively, their respective mean body lengths being 443.9 and 400.8 mm. The largest and the smallest individuals weighed 226.9 and 70.4 g, respectively. The post-dorsal lengths was the only plastic character, out of the 16 characters determined separately in females and males (sex ration of 2.1:1), which showed a substantial between-sexes difference.