FISHERY BULLETIN: VOL 72, NO. 4 



Table 2. — The total number of behavioral interactions between Homarus americanus and PanuUrus interruptus during 10-day 

 experimental periods for the shelter (n = 5 groups) and no shelter (« = 5 groups) conditions, and between P. interruptus and Cancer 

 antennarius during 5-day periods for a no shelter condition (n = 5 groups). Social contact (SC) and no response (NR) for 

 Homarus-initiated interactions include hoth Homarus and PanuUrus actions where only social contact occurred. HA = Homarus 

 approach; HT = Homarus threat; HAT = Homarus attack; PWA = PanuUrus walk away; PAF = PanuUrus abdomen flex; PA = 

 PanuUrus approach; PT = PanuUrus threat; PAT = PanuUrus attack; HWA = Homarus walk away; HAF = Homarus abdomen flex; 

 CA = Cancer approach; CT = Cancer threat; CAT = Cancer attack; CWA = Cancer walk away. 



P.s.t. 



Experimental 

 condition 



SC 



Homarus-initiated interactions 



Actor 



HA 



HT HAT 



NR 



Reactor 



PWA 



PAF 



0800 

 1200 

 1510 

 Totals 



No shelter 

 Shelter 



No shelter 

 Shelter 



No shelter 

 Shelter 



No shelter 

 Percent 



Shelter 

 Percent 



P.s.t. 



Experimental 

 condition 



Panu/(>us-initiated interactions 



PA 



Actor 



PT 



PAT 



NR 



HWA 



Reactor 



HAF 



HT 



HAT 



0800 



1200 



1510 



Totals 



No shelter 

 Shelter 



No shelter 

 Shelter 



No shelter 

 Shelter 



No shelter 

 Percent 



Shelter 

 Percent 



Cancer-Panulirus interactions 



Actor 



Reactor 



NR CWA PWA PAF CT PT CAT 



1= 229 



S = 231 



experiments. Of these, 226 were PanuUrus 

 approach while only 1 was PanuUrus threat 

 (Table 2). There was a total of 277 responses 

 by the reactors (Homarus). Sixteen (6%) of these 

 were classed as no response, 45 (16%) as Homarus 

 walk away, 5 (2%) as Homarus abdomen flex, 

 148 (53%) as Homarus threat, and 63 (23%) as 

 Homarus attack (Table 2). Thus, 76% of H. 



americanus responses to P. interruptus approach 

 were threat and attack. These threats and attacks 

 by H. americanus subsequently resulted in dis- 

 placement of P. interruptus from the immediate 

 area. 



The number of behavioral actions by both the 

 actor (primarily //omarws) and reactor (primarily 

 PanuUrus ) decreased with time, as shown in Table 



1152 



