The developed hybrid eggs of Larimichthys crocea(♀) and Nibea albiflora (♂)were shocked with cold treatment to block the extrusion of the second polar,according to the protocol of inducing meio-gynogenesis in large yellow croaker.Two allotriploid families(PPN1 and PPN2)and the control families were produced.The embryos developed normally,and the morphologic normal fry were hatched out.The development rate,hatching rate and normality rate of the allotriploids were slightly lower than those of the diploid control of large yellow croaker.The results of ploidy analysis showed that the DNA content of the newly hatched fry in PPN1 family was 1.46 time that of diploid large yellow croaker,and the 100% tested fry in PPN1 were triploid.Each offspring in allotriploid families inherited one of alleles from its male parent.Since the gene segregation in Meiosis II was blocked,both homozygotes and heterozytos were found in allotriploid families at four maternal heterozygotic microsatellite loci.The results of the ploid analysis and microsatellite analysis proved the putative triploids contained two genomes from large yellow croaker and a genome from yellow drum.However,the allotriploid fry died one by one from 15 th day post hatching and none survived over one month old,showing that the diploidization of the maternal genome did not improve the survival of the hybrids.Nevertheless,the allotriploid fry can still serve as good materials in genetic mapping and to reveal gene expression and regulation in some important biological processes.