Abstract:
Four different photoperiod (included the control tank or ambient condition tank) were
tested on gestation period in female swordtails and sex fixing on the larvae, tank A were
the ambient conditioned tank, which also acted as controlled tank; tank B were
conditioned with 12 hour of light and 12 hour of darkness (12L: 12D); tank C were
conditioned with 24 hour of light (24L: OD) while tank D were conditioned with 24 hour
of darkness (OL: 24D).
Result of the effect of photoperiod on gestation indicates that the ambient conditioned
fishes shown the shortest gestation period compare to others, its average gestation period
was 30 days. For the 1·2L: 12D conditioned fishes, its average gestation period was 32
days, follow by the 24L:OD conditioned fishes where its average gestation period was 33
days. The longest average gestation period was the OL: 24D conditioned fishes, which
was 35 days. From the One-Way ANOVA statistical analysis, there were differences
between the effects of photoperiods on gestation period in swordtail.