Qin, J., Fast, A.W.-1997
Journal of Applied Ichthyology, 13 (1) : 21-25
Abstract:
Food selection and growth of young snakehead Channa striatus were studied in the laboratory and in a field trial. In the laboratory, first feeding snakehead larvae of 6-7 mm total length (TL) with a mouth opening of 0.55 mm selected for Artemia nauplii, and against formulated feed. Fish began feeding on formulated feed at 12 mm TL when their mouth width reached 1.0 mm. In both laboratory and field trials, snakehead diets changed as fish size increased. For fish 15-20 mm TL, cladocerans and copepods were 96.5% of their diet. With fish 30-40 mm TL, zooplankton consumption was greatly reduced while benthic organism consumption increased. Fish 45-50 mm TL fed exclusively on benthic invertebrates. Diet shift from zooplankton to benthic invertebrates was not due to reduced zooplankton availability, but was instead related to changes in gill raker structure. Low density of benthic invertebrates in the field trial caused reduced fish growth rates when fish switched diets from zooplankton to benthos. Our results indicate that snakehead can take Artemia nauplii as a larval starter food, then accept formulated feed at greater than or equal to 12 mm TL. Zooplankton can serve as food for snakehead < 40 mm, but formulated feed should be provided for larger fish which are unable to catch zooplankton.
(Univ Hawaii Manoa, Hawaii Inst Marine Biol, POB 1346, Kaneohe, HI 96744 USA)
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