Spiny dogfish, Squalus acanthias, caught as bycatch in salmon driftnet fishery in the Pacific off the Kuril Islands and Kamchatka

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Data on spiny dogfish caught by salmon driftnets in the Pacific off the Kuril Islands and Kamchatka are summarized. The highest occurrence of this shark was observed off the southeastern Kamchatkan coast and opposite the First Kuril Strait where it occurred in July–November but most frequently in October–November during northward feeding migrations. Largest specimens (over 90 cm) occurred within the upper 100-m layer only. Catches were represented by individuals of 54–121 cm total length with mean 81.79 cm. Sharks 76–90 cm long were most numerous (62.3%). Latitudinal changes of spiny dogfish length were detected. In southernmost area (44°–45°N), total length varied from 75 to 112 cm (mean 83.8 cm) while in the northernmost one (52°–53°N) it was 91–63 cm with mean 71.7 cm. Catches were represented mostly by immature individuals (97.6% of females and 83.7% of males). Maximum total length of immature females was 109 cm, whereas minimum mature female length was 91 cm. Respective values for males were 82 and 80 cm. There were almost no significant differences in male and female average sizes: mean total length and body weight were 82.7 and 82.2 cm and 1758 and 1820 g, respectively. No relationships between total length and maximum egg diameter and between total length and number of eggs were found. Relationships between total, fork, and standard lengths, body and eviscerated weights are presented. Data on gonado-somatic and hepato-somatic indices, indices of heart and spleen, and condition factor are presented. Diet composition is described.