Hydrobiologia

, Volume 371, Issue 0, pp 143–153

Basic movement pattern and chemo-oriented search towards baited pots in edible crab (Cancer pagurus L.)

  • Katrine Skajaa
  • Anders Fernö
  • Svein Løkkeborg
  • Eli K. Haugland
Article

DOI: 10.1023/A:1017047806464

Cite this article as:
Skajaa, K., Fernö, A., Løkkeborg, S. et al. Hydrobiologia (1998) 371: 143. doi:10.1023/A:1017047806464

Abstract

The basic (natural) movement pattern and gear-induced behaviour of female edible crab Cancer pagurus L. were studied by means of a stationary positioning system. Nine crabs were tagged with ultrasonic transmitters and their positions were monitored approximately every third minute for 9–24 days. Because the crabs sometimes hid, the signals were often received improperly, resulting in inaccurate position fixes, and a computer program to distinguish between movement and inactivity was developed.

Edible crabs showed a nocturnal activity cycle. During the day crabs were in hiding as indicated by less accurate position fixes. There were variations in activity levels both between and within individuals. Three crabs hardly moved at all during the study, while the others were active during some, or all nights. The crabs did not return to the same place after movement, but stayed close to the hydrophone triangle (290 × 350 × 175 m) throughout the study. The activity and movement patterns are discussed in relation to optimal foraging behaviour and predator avoidance.

Six baited pots were set in the area on seven nights. Four of the crabs located baited pots during the study. Three crabs located pots more than once, resulting in a total of nine localisations. Three of the tagged crabs were caught. The localisations of baited pots were divided into four categories on the basis of the current direction at the start of the localisation and whether the crab was caught or not, in order to suggest the probability of the localisation being chemically stimulated. At least six of the localisations seemed to be induced by chemical attraction to the bait. Pots were always located during night at the time of high activity. The searching distances ranged from 12 to 48 m. Speed of movement during searching was higher than speed during basic movement.

edible crabCancer pagurusultrasonic telemetrymovement patternchemoreception

Copyright information

© Kluwer Academic Publishers 1998

Authors and Affiliations

  • Katrine Skajaa
  • Anders Fernö
  • Svein Løkkeborg
  • Eli K. Haugland

There are no affiliations available