The cross breeding and genetic analysis of hybrids of Larimichthys crocea(♀)and Nibea miichthioides(♂)

To understand the feasibility of cross breeding between Larimichthys crocea ♀ and Nibea miichthioides ♂,two hybrid families were built(LN1 and LN2).Ploidy of F1 hybrids was identified.Moreover,ten microsatellite loci were used for genetic relationship analysis between F1 hybrids and their parents.The result showed that L.crocea(♀)and N.miichthioides(♂)can be successfully crossed and hybrid offspring of normal survival were produced.Survival rate of hybrid offspring at the age of 45 days post hatch reached about 30%.However,fertilization rate(29.0%,32.6%)and hatching rate(75.0%,76.7%)of two hybrid families were significantly lower than those in large yellow croaker families(P0.05).Appearance of juvenile hybrid fish is visibly different from those of large yellow croaker,which has characteristics of both parents:slender body,sharp blunt head and their body sides are covered with black-brown spots.The results of DNA relative content investigation and genetic relationship analysis demonstrated that more than 90% of the hybrid offspring were hybrid diploid,in addition,a small number of those were hybrid triploid and gynogenesis diploid.Till the age of 45 days,growth rate of both hybrid diploid and hybrid triploid was slower than that of large yellow croaker.These findings will provide reference for exploitation and management of F1 hybrids of L.crocea(♀)and N.miichthioides(♂).