Journal of the Marine Biological Association of the United Kingdom (New Series)

Research Article

Tunny Investigations made in the North Sea on Col. E. T. Peel's Yacht, “St. George,” Summer, 1933. Part I. Biometric Data

F. S. Russella1

a1 Naturalist at the Plymouth Laboratory.

1. Details are given of the types of hooks lost in tunny in the North Sea in the summer of 1933.

2. Data are given on the measurements made on thirty-two large migrating fish caught in the North Sea in August and September, 1933.

3. In certain body proportions the tunny measured differ from those in the G4 Group (200 to 260 cm. in length) given by Heldt for fish from Tunis and by Frade for fish from Algarve on the south coast of Portugal, while in some characters they resemble the Tunis fish and in others the Algarve fish, but all the North Sea fish were between 232 and 271 cm. in length.

4. It was found that there was a tendency for fish with short second dorsal fins to have short first dorsal, anal, and caudal fins, and for those with long second dorsals to have these other three fins long.

5. Measurements were made to supply data on the condition of the fish.