INTRODUCTION OF DETRITAL FOOD WEBS INTO AN AQUACULTURE SYSTEM BY SUPPLYING SINGLE CELL ALGAL DETRITUS PRODUCED FROM LAMINARIA JAPONICA AS A HATCHERY DIET FOR ARTEMIA NAUPLII

M. Uchida, K. Nakata, M. Maeda-1997

Aquaculture 154: 125-137

Abstract:

A technique to change Laminaria japonica, a macrophyte, thalli into single cell detrital forms, namely, single cell detritus (SCD), was developed utilizing the prominent degrading ability of a marine bacterium, Alteromonas espejiana AR06 (FERM BP-5024). The SCD particles were about 2-10 micro m in diameter and associated with many bacterial cells. The potential use of the SCD particles as a diet for suspension feeder animals was tested by feeding experiments with Artemia. The Laminaria thalli particles of 105-177 micro m in diameter, which were difficult for Artemia to ingest and contributed little to the growth of Artemia, were transformed into a substantial nutrient source after they were degraded to SCD particles by bacteria. Feeding experiments with Laminaria thalli particles of less than 44 micro m in diameter suggested that the axenically prepared SCD itself had a high potential as a hatchery diet and the colonization of the bacterial cells on the SCD would result in the catabolic loss of its total dietary values. This manuscript suggests a novel fish-feeding regime based on algal detritus food webs by convening the macrophyte biomass into SCD-hatchery diets for suspension feeder animals.

(National Research Institute of Fisheries Science, 2-12-4, Fukuura, Kanazawa-ku, Yokohama 236, Japan)

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