Tactile stimulation lowers stress in fish

  • Nature Communications 2, Article number: 534 (2011)
  • doi:10.1038/ncomms1547
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In humans, physical stimulation, such as massage therapy, reduces stress and has demonstrable health benefits. Grooming in primates may have similar effects but it remains unclear whether the positive effects are due to physical contact or to its social value. Here we show that physical stimulation reduces stress in a coral reef fish, the surgeonfish Ctenochaetus striatus. These fish regularly visit cleaner wrasses Labroides dimidiatus to have ectoparasites removed. The cleanerfish influences client decisions by physically touching the surgeonfish with its pectoral and pelvic fins, a behaviour known as tactile stimulation. We simulated this behaviour by exposing surgeonfish to mechanically moving cleanerfish models. Surgeonfish had significantly lower levels of cortisol when stimulated by moving models compared with controls with access to stationary models. Our results show that physical contact alone, without a social aspect, is enough to produce fitness-enhancing benefits, a situation so far only demonstrated in humans.

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  1. 1.

    Social status and health in humans and other animals. Annu. Rev. Anthropol. 33, 393–418 (2004).

  2. 2.

    , & Social modulation of stress responses. Physiol. Behav. 79, 399–407 (2003).

  3. 3.

    , & In search of relationships between the acute adrenocortical response and fitness. Gen. Comp. Endocrinol. 157, 288–295 (2008).

  4. 4.

    Stress in fishes: a diversity of responses with particular reference to changes in circulating corticosteroids. Integ. Comp. Biol. 42, 517–525 (2002).

  5. 5.

    Touch therapies for pain management and stress reduction: in Health Psychology Through the Life Span: Practice and Research Opportunities (eds. Resnick, R.J. & Ronald, H.R.) 313–321 (American Psychological Association, 1996).

  6. 6.

    , & Cortisol decreases and serotonin and dopamine increase following massage therapy. Intern. J. Neuroscience 115, 1397–1413 (2005).

  7. 7.

    , , , & Effects of a full-body massage on pain intensity, anxiety, and physiological relaxation in Taiwanese patients with metastatic bone pain: a pilot study. J. Pain Symp. Manag. 37, 754–763 (2009).

  8. 8.

    et al. Effects of different kinds of couple interaction on cortisol and heart rate responses to stress in women. Psychoneuroendocrinology 32, 565–574 (2007).

  9. 9.

    The social role of touch in humans and primates: behavioural function and neurobiological mechanisms. Neurosci. Biobehav. Rev. 34, 260–268 (2010).

  10. 10.

    , & On the physiology of grooming in a pigtail macaque. Physiol. Behav. 45, 667–670 (1989).

  11. 11.

    , , & Relationship between social factors and pituitary: adrenocortical activity in female rhesus monkeys (Macaca mulatta). Horm. Behav. 27, 318–331 (1993).

  12. 12.

    , & Heart rate responses to social interactions in free-moving rhesus macaques (Macaca mulatta): a pilot study. J. Comp. Psychol. 113, 59–65 (1999).

  13. 13.

    , , & Grooming in Barbary macaques: better to give than to receive. Biol. Lett. 3, 231–233 (2007).

  14. 14.

    Sociometrics of Macaca mulatta—linkages and cliques in grooming matrices. Folia Primatol. 18, 196–223 (1972).

  15. 15.

    , & Beta-endorphin concentrations in cerebrospinal-fluid of monkeys are influenced by grooming relationships. Psychoneuroendocrinology 14, 155–161 (1989).

  16. 16.

    , , , , & Focused grooming networks and stress alleviation in wild female baboons. Horm. Behav. 54, 170–177 (2008).

  17. 17.

    Oxytocin may mediate the benefits of positive social interaction and emotions. Psychoneuroendocrinology 23, 819–835 (1998).

  18. 18.

    Reduced anxiety in postpartum rats requires recent physical interactions with pups, but is independent of suckling and peripheral sources of hormones. Horm. Behav. 47, 241–255 (2005).

  19. 19.

    Relationship between cleaning rates and ectoparasite loads in coral reef fishes. Mar. Ecol. Prog. Ser. 118, 8–51 (1995).

  20. 20.

    Evolution and ecology of cleaning symbioses in the sea. Oceanogr. Mar. Biol. 38, 311–355 (2000).

  21. 21.

    Spatio-temporal variation and feeding selectivity in the diet of the cleaner fish Labroides dimidiatus. Copeia 1997, 346–355 (1997).

  22. 22.

    & Cleaner fish prefer client mucus: support for partner control mechanisms in cleaning interactions. (Biol. Lett.) Proc. R. Soc. Lond. B 270 (Supp.), 242–244 (2003).

  23. 23.

    & Asymmetric cheating opportunities and partner control in a cleaner fish mutualism. Anim. Behav. 63, 547–555 (2002).

  24. 24.

    & Cleaner fish Labroides dimidiatus manipulate client reef fish by providing tactile stimulation. Proc. R. Soc. Lond. Ser. B 268, 1495–1501 (2001).

  25. 25.

    Cleaner fish use tactile dancing behaviour as a preconflict management strategy. Curr. Biol. 14, 1080–1083 (2004).

  26. 26.

    Cleaning symbioses. Symbiosis 4, 58–229 (1987).

  27. 27.

    , , & Do cleaning organisms reduce the stress response of client reef fish? Front. Zool. 4, 21 (2007).

  28. 28.

    et al. Does access to the bluestreak cleaner wrasse Labroides dimidiatus affect indicators of stress and health in resident reef fishes in the Red Sea? Horm. Behav. 59, 151–158 (2011).

  29. 29.

    & Evolution of sensory pathways in vertebrates. Brain Behav. Evol. 50, 189–197 (1997).

  30. 30.

    Comparison of methods for sampling ectoparasites from coral reef fishes. Mar. Freshw. Res. 46, 897–903 (1995).

  31. 31.

    Ethics and welfare: pain perception in fish. Bull. Eur. Assoc. Fish Path. 26, 6–10 (2006).

  32. 32.

    , & Do fishes have nociceptors? Evidence for the evolution of a vertebrate sensory system. Proc. R. Soc. Lond. B 270, 1115–1121 (2003).

  33. 33.

    , & Does cleaner fish service quality depend on client value or choice options? Anim. Behav. 76, 123–130 (2008).

  34. 34.

    , & Behavioral indicators of stress-coping style in rainbow trout: do males and females react differently to novelty? Physiol. Behav. 87, 506–12 (2006).

  35. 35.

    & Serum cortisol response to handling stress and the effect of cortisol implantation on testosterone level in the tilapia, Oreochromis mossambicus. Aquaculture 115, 145–158 (1993).

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We thank the directors and staff of Lizard Island Research Station for their support and friendship. We also thank Isabelle Côté for helpful comments on an earlier version of the manuscript. Ethical permits were provided by The University of Queensland. M.C.S. is supported by the Portuguese Foundation for Science and Technology-FCT (grant PTDC/MAR/105276/2008), R.B. and A.F.H.R. are financed by the Swiss Science Foundation (SNF) and R.F.O. by the the Pluriannual Programme of FCT (R&D Unit 331/2001). We are grateful to Pedro Gonçalves for making the mechanical apparatus and all cleaner models. We also thank Ana Sofia Felix for running the hormone assays. The use of animals and data collection complied with the laws of Australia, Portugal and Switzerland.

Author information


  1. Unidade de Investigação em Eco-Etologia, ISPA - Instituto Universitário, Rua Jardim do Tabaco 34, 1149-041 Lisboa, Portugal.

    • Marta C. Soares
    •  & Rui F. Oliveira
  2. Université de Neuchâtel, Institut de Zoologie, Rue Emile-Argand, 11, 2009 Neuchâtel, Switzerland.

    • Marta C. Soares
    • , Albert F.H. Ros
    •  & Redouan Bshary
  3. Champalimaud Neuroscience Programme, Instituto Gulbenkian de Ciência, Oeiras, Portugal.

    • Rui F. Oliveira
  4. The University of Queensland, School of Biological Sciences, St Lucia, Queensland 4072, Australia.

    • Alexandra S. Grutter


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M.C.S. and R.B. planned the research; M.C.S. collected and analysed data; M.C.S., R.F.O., A.F.H.R., A.S.G. and R.B. wrote the paper.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to Marta C. Soares.

Supplementary information


  1. 1.

    Supplementary Movie 1

    An interaction event where a surgeonfish allocated to treatment approaches a moving cleaner model.


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