Cardiac and behavioural responses of mussels to risk of predation by dogwhelks

Citation
F. Rovero et al., Cardiac and behavioural responses of mussels to risk of predation by dogwhelks, ANIM BEHAV, 58, 1999, pp. 707-714
Citations number
38
Categorie Soggetti
Animal Sciences","Neurosciences & Behavoir
Journal title
ANIMAL BEHAVIOUR
ISSN journal
00033472 → ACNP
Volume
58
Year of publication
1999
Part
4
Pages
707 - 714
Database
ISI
SICI code
0003-3472(199910)58:<707:CABROM>2.0.ZU;2-C
Abstract
We used noninvasive, infrared phototransducers to record continuously the h eartbeat of common mussels, Mytilus edulis, experiencing successive phases of interaction with the predatory gastropod Nucella lapillus, from initial threat to attack and consumption. Coupling physiological monitoring with be havioural analysis allowed us to investigate in detail the responses of mus sels to predation threat. Compared to values of normal feeding activity, he art rate increased significantly when mussels were in the presence of efflu ent from dogwhelks. When attacked by dogwhelks, mussels increased their hea rt rate further, together with the rate of valve gaping. Considering the he art rate as a reliable estimator of respiratory function, these cardiac res ponses might be a mechanism to compensate for increased energy demand in or der to cope with predation hazard. If so, the theoretical importance of tra ding off energy balance against risk of predation is supported by our resul ts. Cardiac and behavioural responses varied throughout the attack accordin g to the penetration method adopted by dogwhelks. When mussels were attacke d through a drilled hole, heart rate tended to increase and periods of card iac pausing appeared close to the point of death. In contrast, mussels atta cked by penetration between the valves showed decreasing heart rate through out the attack, together with relatively earlier cessation of valve gaping and appearance of cardiac pausing. These differences clearly support the hy pothesis that dogwhelks penetrating between the valves are able to induce m uscular paralysis of prey by injecting toxins. (C) 1999 The Association for the Study of Animal Behaviour.