Spent females of deep-water squid Gonatopsis octopedatus Sasaki, 1920 (Gonatidae) in the epipelagic layer of the Okhotsk and Japan seas

• Main Author: Nesis, Kir N.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Moscow State University 1993
• Subjects: Okhotsk; okhotsk sea
• Online Access: https://oceanrep.geomar.de/id/eprint/38056/; https://oceanrep.geomar.de/id/eprint/38056/1/2772.pdf

Four spent females of deep-sea pelagic gonatid squid Gonatopsis octopedatus, dorsal mantle length 24-39 cm, were caught in the 0-50 m layer of the Okhotsk Sea over the depths of 92-126 and approximately 3300 m. Two alike but smaller (12-13.5 cm) females were caught at the surface of the Japan Sea over the depths of 3000-3300 m. They were degenerated, combjelly-like in consistence, most of the arm armature was lost, the oviducts were empty or contained not more than 3-5 eggs up to 4.0-4.3 mm in length. On the contrary, mature males were not degenerated, with most arm hooks and suckers present. The gelatinous degeneration in females begins rather early, at 11 or 111 maturity stages, but at very different sizes. In this period the feeding stops, as degenerated females cannot catch prey. It is supposed that females spawn and juveniles hatch in deep layers, all the eggs are spawned in a short time, and then the females come passively to the surface and die. The difference in size · between females from the two seas may be caused by difference in productivity between very productive Okhotsk Sea and less productive Japan Sea.