Appendix A (Table A1). Scoring system of crayfish aggression adapted from Karavanich and Atema (1998).
Score |
Behavior |
Definition |
-2 |
Fleeing |
Walking away (rapidly), tail flip |
-1 |
Avoidance |
Walking away (slowly), turning away |
0 |
Separate |
At least one body length apart or not facing each other |
1 |
Initiation (no contact) |
Facing, approaching, turning towards opponent |
2 |
Threat display (no contact) |
High on legs, claws open, meral spread, claws forward, antennae point |
3 |
Physical contact (no claw grasping) |
Antenna touching or whipping, claw touching, tapping or pushing |
4 |
Physical contact (claw grasping) |
Claws used to grasp opponents claws (claw lock) |
5 |
Unrestrained use of claws |
Snapping, ripping, swimming while in claw lock, grasping legs or rostrum |
LITERATURE CITED
Karavanich, C., and J. Atema. 1998. Individual recognition and memory in lobster dominance. Animal Behaviour 56:1553–1560.