Motor vessel "N. B. Scofield" cruise one of 1953. Cruise Report 53-S-1

(PDF contains 7 pages.)

On the diel rhythm of motor activity in perch [Translation from: Informatsionnyi Byulleten Biologiya Vnutrennikh Vod No.30, 12-14, 1976]

The river perch (Perca fluviatilis L.) is most active in the daytime hours, and displays seasonal changes of diel rhythm with a break of the rhythm in spring and autumn. In the present work data were obtained on the motor activity of 3 perch measuring l8-20 cm, caught by net in the littoral of a reservoir and spawned under laboratory conditions. The degree of intensity of movement of perch was judged by special experiments. The results are summarised in this short paper.

Motor boat "Constance"

A man on a white motor boat called "Constance" in North West England, UK. This photo is part of a Photo Album that includes pictures from 1935 to 1954.