Interaction of light and diets containing carotenoids on growth rate and coloration of green swordtail, Xiphophorus helleri Heckel 1848

Tizkar, Babak; Zoughi Shalmani, Afshar; Abedi, Mohsen; Rahanandeh, Mohammad

doi:10.22124/janb.2021.5799

Interaction of light and diets containing carotenoids on growth rate and coloration of green swordtail, Xiphophorus helleri Heckel 1848

Authors

¹ Aquatics and Fisheries Research Department, Guilan Agricultural and Natural Resources Research and Education Center, AREEO, Rasht, Guilan, Iran

² Institute of Agricultural Education and Extension, Agricultural Research Education and Extension Organization (AREEO), Tehran, Iran

10.22124/janb.2021.5799

Abstract

This study was performed to investigate the interaction effects of astaxanthin and beta-carotene pigments in white and red lights on growth performance and coloration of swordtail, Xiphophorus helleri. A total of 180 swordtail with an average weight of 1.4 ± 0.1 g with three diets containing 150 mg/kg astaxanthin, 150 mg/kg beta-carotene and a diet without additive pigment and treatments in contrast to white and red lights with light intensity of 1200 lux was fed in 6 treatments and 3 replications for 8 weeks. Finally, growth indices including body weight gain, specific growth rate, feed conversion ratio and survival rate were determined. In order to determine the number of changes in color intensity and sharpness, Hue and Chroma coefficients were determined after shooting and analyzing the obtained colors using coefficients a and b with Photoshop software in the fourth and eighth weeks. The results revealed that there was no interaction between diets and ambient light, but fish raised in white light were superior in terms of all growth and survival indices (p<0.05). These results also exhibited that the effects of color sharpness (Hue) and red color index (Chroma) were greater in diets containing pigments exposed to white light.

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