Environmental Biology of Fishes

, Volume 54, Issue 4, pp 433–437

Feeding and Growth Response of Roach, Rutilus rutilus, to Alarm Substance

  • Anna Jachner
  • Tomasz Janecki

DOI: 10.1023/A:1007523732293

Cite this article as:
Jachner, A. & Janecki, T. Environmental Biology of Fishes (1999) 54: 433. doi:10.1023/A:1007523732293


Feeding and growth responses of roach from three size classes to alarm substance (Schreckstoff) were quantified in laboratory experiments. Larger fish (60.0–80.0 mm in length) reacted stronger to treatment than two smaller sized groups (35.0–45.0 and 46.0–55.0 mm) lowering feeding rate by 80 and 40 and 50%, respectively. The reduction in feeding rate of larger fish caused decrease in growth rate in length and weight, while the lowered consumption of smaller fish caused only reduction in growth rate in weight. Condition factor of exposed to alarm substance small sized roach was lower than that of the control individuals and roach from other two size classes, both, treated and untreated. The difference in growth response to a danger of predation has its roots probably in different metabolism and growth rates of small and large fish. Small fish have higher metabolic rate and less lipid reserves than larger ones, therefore they are probably forced to feed to be able to grow. Also, small sized roach is more vulnerable to predation than large sized fish, thus growing fast seem to be crucial for survival in a risky environment. Study shows that small roach trade off their safety against food, feeding in risky environment to sustain fast growth. This ability of fast outgrowing of a dangerous, vulnerable to predators, size increases survival of juveniles in dangerous environment.

Shreckstoff food intake growth rate condition factor 

Copyright information

© Kluwer Academic Publishers 1999

Authors and Affiliations

  • Anna Jachner
    • 1
  • Tomasz Janecki
    • 1
  1. 1.Department of Hydrobiology, Institute of ZoologyUniversity of WarsawWarsaw, Banacha 2Poland (e-mail address
  2. 2.Department of Antarctic BiologyPolish Academy of SciencesWarsaw, Ustrzycka 10Poland

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