Fork length, body mass, gonadosomatic index and spermiation or ovulation ratio (ratio of fish that had spermiated or ovulated) of homing adults in 2002
| Sex . | Point . | Date of sampling . | N . | FL (cm) . | BM (kg) . | GSI (%) . | Spermiation or ovulation (%) . |
|---|---|---|---|---|---|---|---|
| Male | A | 19 Sep. | 10 | 67.3±1.8 | 3.84±0.24a,b | 5.01±0.18* | 0.0 |
| B | 30 Sep. | 10 | 69.0±1.3* | 3.83±0.22a,b | 5.91±0.24* | 0.0 | |
| C | 1 Oct. | 10 | 72.3±1.1* | 4.50±0.22a* | 5.07±0.11* | 0.0 | |
| D | 2 Oct. | 5 | 67.9±1.2 | 3.66±0.25a,b | 5.24±0.16* | 0.0 | |
| E | 3 Oct. | 8 | 65.1±2.2 | 3.12±0.29b | 5.25±0.59* | 0.0 | |
| F | 3 Oct. | 8 | 71.9±1.3* | 4.14±0.28a,b,* | 4.64±0.48* | 75.0 | |
| G | 2 Oct. | 10 | 68.5±1.4* | 3.61±0.25a,b | 4.97±0.38* | 100.0 | |
| Female | A | – | 11 | 67.4±1.3* | 3.86±0.20* | 12.91±0.42a,* | 0.0 |
| B | – | 10 | 67.8±1.1* | 3.68±0.21* | 14.86±0.32a,b,* | 0.0 | |
| C | – | 10 | 69.4±1.0* | 3.96±0.19* | 16.90±0.85b,c,* | 0.0 | |
| D | – | 8 | 65.8±0.8 | 3.40±0.16 | 15.76±0.42a,b,* | 0.0 | |
| E | – | 8 | 68.8±0.9* | 3.84±0.22* | 16.37±0.54b,* | 0.0 | |
| F | – | 9 | 68.4±1.3* | 3.60±0.25 | 20.64±1.29c,d,* | 33.3 | |
| G | – | 10 | 66.7±1.4 | 3.21±0.23 | 21.46±1.14d,* | 100.0 |
| Sex . | Point . | Date of sampling . | N . | FL (cm) . | BM (kg) . | GSI (%) . | Spermiation or ovulation (%) . |
|---|---|---|---|---|---|---|---|
| Male | A | 19 Sep. | 10 | 67.3±1.8 | 3.84±0.24a,b | 5.01±0.18* | 0.0 |
| B | 30 Sep. | 10 | 69.0±1.3* | 3.83±0.22a,b | 5.91±0.24* | 0.0 | |
| C | 1 Oct. | 10 | 72.3±1.1* | 4.50±0.22a* | 5.07±0.11* | 0.0 | |
| D | 2 Oct. | 5 | 67.9±1.2 | 3.66±0.25a,b | 5.24±0.16* | 0.0 | |
| E | 3 Oct. | 8 | 65.1±2.2 | 3.12±0.29b | 5.25±0.59* | 0.0 | |
| F | 3 Oct. | 8 | 71.9±1.3* | 4.14±0.28a,b,* | 4.64±0.48* | 75.0 | |
| G | 2 Oct. | 10 | 68.5±1.4* | 3.61±0.25a,b | 4.97±0.38* | 100.0 | |
| Female | A | – | 11 | 67.4±1.3* | 3.86±0.20* | 12.91±0.42a,* | 0.0 |
| B | – | 10 | 67.8±1.1* | 3.68±0.21* | 14.86±0.32a,b,* | 0.0 | |
| C | – | 10 | 69.4±1.0* | 3.96±0.19* | 16.90±0.85b,c,* | 0.0 | |
| D | – | 8 | 65.8±0.8 | 3.40±0.16 | 15.76±0.42a,b,* | 0.0 | |
| E | – | 8 | 68.8±0.9* | 3.84±0.22* | 16.37±0.54b,* | 0.0 | |
| F | – | 9 | 68.4±1.3* | 3.60±0.25 | 20.64±1.29c,d,* | 33.3 | |
| G | – | 10 | 66.7±1.4 | 3.21±0.23 | 21.46±1.14d,* | 100.0 |
FL, fork length; BM, body mass; GSI, gonadosomatic index
A–G, correspond to the sampling points in Fig. 1B; A, Northeast coast of Hokkaido; B,C, coastal areas in Ishikari Bay; D, Ishikari River estuary; E,midway point of the upriver migration; F, fish wheel located 4 km downstream of the hatchery; and G, the Chitose salmon hatchery
Values are means ± s.e.m. Superscripts letters indicate significant difference (P<0.05) within the same sex and year. *P<0.05 compared to maturing adult I in the central Bering Sea
Data in 2001 and 2003 are shown in Table S2 in supplementary material