Abstract:Oratosquilla oratoria is the main catch of drift net fishery in the nearshore area of Haiyang. To achieve sustainable use of resources, it is necessary to study the population status and life history characteristics of this species. During the period from March 2018 to September 2019, O. oratoria samples caught by a drifter in the Haiyang inshore current were analyzed monthly, excluding the months of the summer fishing moratorium. The body length and body weight of the samples were measured, the feeding intensity and ovarian development degree of the females were identified, and the ratio of males to females in the catch was calculated. The results showed that the ratio of males to females was 1: 1.03 over the whole year of catching. There was no significant difference in average body length between male and female samples in April and December (P>0.05), but there were significant differences in other months (P<0.05). The dominant body length of female O. oratoria ranged from 100 to 140 mm, with dominant body weight ranging from 10 to 40 g. The dominant body length of male O. oratoria was 110~150 mm, with a dominant body weight of 20~50 g. Except for December, there were significant differences in body length distribution between male and female samples in all months (P<0.05). The gonad maturity of female O. oratoria samples ranged from stages Ⅰto Ⅳ over the whole year, with individuals in stages Ⅲ and Ⅳ primarily appearing from April to May, and October to January of the following year. May and January represent the 2 peak periods of sexual maturity for females. In October, the empty stomach rate of male and female O. oratoria was the lowest in the whole year, with the highest relative growth rate of body length. The relationship between body length and weight of female O. oratoria was W=5.39×10–5L2.709 8 (R2=0.825 4, P<0.05), while the relationship between body length and weight of male O. oratoria was W=2.62×10–5L2.874 4 (R2=0.798 6, P<0.05). In addition, there were some differences between the male and female group structures.
