Publication Date:
2021-05-19
Description:
Survey is conducted to evaluate the effects of different intensities and durations of red light spectrums on growth performance and survival of Caspian trout (Salmo trutta caspius) in Coldwater Fishes Research Center (CFRC). According to the standard methods and manuals, selected 1.1±0.2 g (1755 individuals) larvae transferred from a registered and well-known hatchery and introduced to the fish tanks in CFRC after quarantine and adaptation procedures. The trial designed for 9 treatments with 3 repeats and fish tanks (California troughs) stocked by 65 larvae. All tanks were separated by dark plastic sheets individually to more controlling actions on special lighting regimes, except controls. Lighting actions were conducted as long as survey stage for 36 days by economic lamps (P: 40/50 W, =550/880 lum) on lighting durations of 12/12, 10/14, 14/10 h (on/off) and 24 (on) by 40/50 W lamps respectively for treatment 1 to 8. Controls are considered in treatment No. 9 by natural and environmental lighting regime. The biometry operations were carried out in a 6 days interval. Results were analyzed with SPSS (Version 12) software and by ANOVA one way analysis method and multiple levels of Duncan Test; graphs were illustrated by Excel software. According to the results, most of the measured factors as growth indicators (FW, WG, FCR and SGR) in treatments (1-8) had showed significant differences in compare of control. In this case, oily drips in retina layer of eye s larvae absorb the short light spectrums and let the long spectrums to be transferred. Thus because of more vision, feeding behavior could develop with lower stress condition. Moreover, some growth factor (SGR, WG and FCR) rates in larvae showed better values significantly in treatment (1) (12/12 h lighting with 550 lum) in compare of other treatments and controls (P≤ 0.05). In addition, there are not any harmonized and expected growth parameters with synchronized red lighting intensities and durations in the Caspian trout larvae. It seems that recent demonstrations were influenced by physiological effects of some endocrinal glands and brain neurotransmitters.
Description:
Iranian Fisheries Science Research Institute
Description:
Published
Keywords:
Physiological
;
Environmental
;
Caspian trout
;
Salmo trutta caspius
;
Larvae
;
Red light
;
Light strengthen
;
Light duration
;
Growth
;
Survey
;
Survival
;
Coldwater
;
Feeding
Repository Name:
AquaDocs
Type:
Report
,
Refereed
Format:
54pp.
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