Growth Responses and Survival of the Goldfish, Carassius auratus (Cyprinidae) Fry Reared on Moina (Cladocera) and Cyclops (Copepoda)
AbstractFive sets of 20-day old goldfish fry, Carassius auratus with average weights of 0.167 ± 0.003 g were reared for eight weeks in plastic bowls for growth and survival studies. One set (labelled MN) was fed Moina and Cyclops. A second set (labelled FM) was fed fishmeal, and a third set (labelled AF) was fed a 45% protein artificial feed. The fourth and fifth sets were fed mixtures of Moina/Cyclops with the fishmeal (MFM) and the artificial feed (MAF). Survival was 60% in the fry fed fishmeal (FM) alone but 100% in all the other groups. Specific growth rate (SGR) and mean weight gain was not significantly different (P > 0.05) in fry fed Moina/Cyclops alone (MN) or in combination with fishmeal (MFM) and artificial feed (MAF). They were, however, significantly different (P < 0.05) from those of fry fed fishmeal (FM) and artificial feed (AF) The best mean weight gain of 2.796 ± 0.006 g (over 1600%) was recorded in the fry fed Moina/Cyclops alone. Weekly percentage weight gain also followed a similar trend. Moina/Cyclops are recommended to aquaculturists for goldfish fry rearing instead of artificial feeds, fishmeal or the expensive Artemia franciscana. It is also recommended that this zooplankton be augmented in later stages with fishmeal to enhance fry growth and survival.
Key words: Moina, Cyclops, Goldfish, Carassius auratus, Larval fish nutrition.
Journal of Aquatic Sciences Vol.18(1) 2003: 43-46