THE IMPACT OF WATER TEMPERATURE ON THE GROWTH AND SURVIVAL OF JUVENILE NORTHERN PIKE (ESOX LUCIUS L.) REARED ON FORMULATED FEED
Mirosław Szczepkowski
Department of Lake Fisheries, The Stanisław Sakowicz Inland Fisheries Institute in Olsztyn, Poland
ABSTRACT. The aim of the experiment was to determine the impact water temperature has on the growth and survival of juvenile northern pike, Esox lucius L., reared on formulated feed. The initial experimental material weighed 5.7 g and measured 8.8 cm in body length and was stocked into three recirculating systems (water temperature 20, 24, 28°C) and reared for 21 days. The highest final body weight was obtained by the fish reared at 28°C. Statistically significant differences were confirmed between these fish and those reared at a temperature of 20°C (P < 0.01), but no such differences were recorded with regard to the group of fish reared at 24°C (P > 0.05). At a temperature of 28°C, the survival of the fish was significantly higher at 98.7% (P < 0.05). A statistically significant difference (P < 0.05) was also confirmed in the feed conversion ratio (FCR) between the groups reared at water temperatures of 20 and 28°C at 0.61 ± 0.05 and 0.71 ± 0.04, respectively.
Key words: NORTHERN PIKE (ESOX LUCIUS), TEMPERATURE, FORMULATED FEED, GROWTH, RECIRCULATION SYSTEMS
CORRESPONDING AUTHOR:
Dr Mirosław Szczepkowski, Instytut Rybactwa Śródlądowego, Doświadczalny Ośrodek Zarybieniowy „Dgał“, 11-610 Pozezdrze, Pieczarki 50, Tel./Fax: +48 (87) 4283666;
e-mail: szczepkowski@infish.com.pl