tailieunhanh - Manual on the Production and Use of Live Food for Aquaculture - Phần 3

Tham khảo tài liệu 'manual on the production and use of live food for aquaculture - phần 3', nông - lâm - ngư, ngư nghiệp phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | nn n Q 3 Q 3. ROTIFERS . Introduction . Morphology . Biology and life history . Strain differences . General culture conditions . Nutritional value of cultured rotifers . Production and use of resting eggs . Literature of interest Worksheets Philippe Dhert Laboratory of Aquaculture Artemia Reference Center University of Gent Belgium EBB Q 3 Q . Introduction Although Brachionusplicatilis was first identified as a pest in the pond culture of eels in the fifties and sixties Japanese researchers soon realized that this rotifer could be used as a suitable live food organism for the early larval stages of marine fish. The successful use of rotifers in the commercial hatchery operations of the red sea bream Pagrus major encouraged investigations in the development of mass culture techniques of rotifers. Twenty five years after the first use of rotifers in larviculture feeding several culture techniques for the intensive production of rotifers are being applied worldwide. The availability of large quantities of this live food source has contributed to the successful hatchery production of more than 60 marine finfish species and 18 species of crustaceans. To our knowledge wild populations of rotifers are only harvested in one region in the . China . the Bohai Bay saltworks where Brachionusplicatilis is used as food in local shrimp and crab hatcheries. The success of rotifers as a culture organism are manifold including their. planctonic nature tolerance to a wide range of environmental conditions high reproduction rate . Moreoever their small size and slow swimming velocity make them a suitable prey for fish larvae that have just resorbed their yolk sac but cannot yet ingest the larger Artemia nauplii. However the greatest potential for rotifer culture resides however is the possibility of rearing these animals at very high densities . densities of 2000 have been reported by Hirata 1979 .