Abstract
Light is a major environmental factors that synchronize all life-stages of fish, from body growth to sexual maturation. The objective of this research is to enhance the growth and reproductive performance in the test fish, red eyed orange molly (Poecilia sphenops) exposed to standardized manipulated photoperiod. In present study, growth and gonadal development of the test fish with an average initial weight (0.52g) and an average total length (3.2cm) exposed to two photoperiods (18L:6D and 10L:14D) at constant light intensity (1500 lx) for a period of 60 days was investigated. The fish were fed with formulated feed twice a day as per 10% of body weight. During a long day photoperiod (18L:6D) significant increase in growth parameters such as, weight gain (2.2 ± 0.04), feed conversion ratio (8.9 ± 0.004) and specific growth rate (1.2 ± 0% day-1) was observed. Mean gonadosomatic index (GSI) in female (30.4± 0.11) and male fish (2.0 ± 0.17) was also significantly higher in long-day photoperiod followed by short day photoperiod (10L:14D). The results confirm that manipulated long-day photoperiod induced somatic growth and enhanced gonadal development in P. sphenops without causing any stress.
Summary This work is novel to research field since photoperiodic effect on Poecilia sphenops, a live-bearer fish under artificial environmental conditions resulted in enhanced growth and reproductive performance with fry production.