The Evaluation On The Releasing Of Penaeus Japonicus In Laoshan Bay And Primary Research On Paralichthys Olivaceus In Guzhenkou Bay

The researchers released about 63.28 million Penaeus japonicas in Laoshan Bay which the body-length was about from 8.1cm to 11.0cm. The released Penaeus japonicas were sampled periodically. This paper makes researches on the migration, growth characteristics and recapture rate of the Penaeus japonicas in Laoshan Bay .The results showed that the releasing Penaeus japonicus mainly distributed around the alongshore of Aoshantou and Xiaoguan Island where the water depth is less than 5m, and with the decline of the water temperature in September they migrate from shallow water to the deep water. The fishermen began to recapture Penaeus japonicus from August to October and the recapture rate was just about 0.48%. The data of body-length and body-weight was analyzed by the software STATISTIC A 6.0, and the relationship between them showed as follows,Female,Male,According to the equation we can get the age equation of turning point (t_r= 87.7d), the maximum daily growth (dw_tr/dt_r= 0.39g) for female and the age equation of turning point (t_r = 78.2d), the maximum daily growth (dw_tr/dt_r = 0.35g) for male. The largest growth rate will be at September 2 for female and August 24 for male, so the better time for capture may be after mid-September.In order to recover the yield and evaluate the releasing effect of Paralichthys olivaceus Qingdao Marine Fisheries Service released 10000 healthy individuals to Guzhenkou Bay at September 25 in 2008. All the body-length of the offspring were over than 9cm and tags were put on them for tracking. The results showed that the growth status of Paralichthys olivaceus was good according to the recaptured individuals at March 11 and April 11 in 2009. The further study may be conducted in autumn of 2009 due to the growth cycle of Paralichthys olivaceus.