The influence of photoperiod on growth and survivorship of fry of the armoured catfish, Hoplosternum littorale (Hancock). (102)

Abstract

Small groups of larval armoured catfish, Hoplosternum littorale, were reared for a period of five weeks at three photoperiod cycles: 24L:0D; 12L:12D; and 0L:24D, and were fed live Artemia salina, ad libitum, three times daily. The fish reared in complete darkness showed the greatest increase in weight (14 433%) while those reared in continuous light had the smallest increase in weight (4 762%).These results were highly significantly different (P < 0.001; Tukey’s HSD test). A similar effect was seen with increase in length. Survivorship varied with photoperiod cycles with 80.67% at 24L:0D; 79% at 12L:12D; and 58.24% at 0L:24D, but these results were not significantly different. This study indicates that there is merit to raising larval armoured catfish in darkness due to their photophobic nature during the larval stages.