EFFECTS OF HEAT EXTRACT FROM FIREFLY SQUID, Watasenia scintillans, ON THE NONSPECIFIC DEFENCE MECHANISMS AND PROTECTION AGAINST FURUNCULOSIS IN RAINBOW TROUT (Oncorhynchus mykiss)

Andrzej K. Siwicki; Tougo Miyazaki; Isao Komatsu; Toshihito Matsusato; Krzysztof Goryczko; Elżbieta Terech-Majewska

Andrzej K. Siwicki
Tougo Miyazaki
Isao Komatsu
Toshihito Matsusato
Krzysztof Goryczko
Elżbieta Terech-Majewska

Keywords: FIREFLY SQUID, DEFENCE MECHANISMS, PHAGOCYTES, LYSOZYME, RAINBOW TROUT

Abstract

Influence of heat extract from firefly squid (FSE-1) on the nonspecific cellular and humoral defence mechanisms in rainbow trout experimentally infected with Aeromonas salmonicida was examined. After application of FSE-1 by intraperitoneal injection or immersion, phagocytic ability of neutrophils, respiratory burst activity and potential killing activity of blood phagocytes, lysozyme activity and total Ig level in plasma were measured. One week after these fishes were inoculated with live and virulent Aeromonas salmonicida by intraperitoneal injection, the same kinds of parameters were measured and compared with the control. The results showed that FSE-1 applicated by immersion or injection significantly (p<0.05) increased the phagocytic ability of neutrophils, respiratory burst activity and potential killing activity of phagocytes, lysozyme activity and total Ig level in serum, compared to the control. After artificial infection, all of the immunological parameters of both injected or immersed fishes with FSE-1 significantly increased compared with the control. These results indicate that FSE-1 administration accelerates nonspecific cellular and humoral defence mechanisms and protection against furunculosis in rainbow trout.