Fright reaction in Gymnocharacinus bergi (Pisces, Characidae), a relic fish from Patagonia

• Published in: Environmental biology of fishes Vol. 58; no. 2; pp. 227 - 232
• Main Authors: LOZADA, M, ORTUBAY, S, CUSSAC, V
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer 01.06.2000; Springer Nature B.V
• Subjects: Agnatha and pisces; Animal behavior; Animal ethology; Aquariums; Biological and medical sciences; Characidae; Environmental conditions; Fish; Freshwater; Fundamental and applied biological sciences. Psychology; Gymnocharacinus bergi; Marine biology; Pheromones; Predation; Psychology. Psychoanalysis. Psychiatry; Swimming; Vertebrata; South America; Argentina; America; Freshwater environment; Vertebrata; Pisces; Environmental factor; Stream; Alarm pheromone; Antipredator behavior; Aves; Defense; Relict species; Dose activity relation
• ISSN: 0378-1909; 1573-5133
• DOI: 10.1023/A:1007630728551

Fright reaction, mediated by pheromones, is an antipredatory mechanism in the scale-less 'mojarra' Gymnocharacinus bergi (Pisces, Characidae). The aim of this study was to characterise and quantify the fright reaction of this species and to analyse the alarm response to different doses of alarm substance. The alarm response consisted in a general decrease in the swimming speed and a tendency to remain at the bottom of the test aquarium. A threshold effect was induced by a very low dose of alarm substance, and the intensity of the fright reaction was positively correlated to the dose concentration. The main characteristics of the alarm response appear to be consistent with G. bergi's environmental conditions such as: a higher predation risk in the upper stratum, the abundant pond-weeds of the stream and the great flow and fast speed of the clear waters.