Based on the survey data from the bottom-trawl surveys in Shandong coastal waters in autumn (October 2016), winter (January 2017), spring (May 2017) and summer (August 2017), the seasonal variations of population structure and spatial distribution of Cleisthenes herzensteini were studied. The results showed that the average length of C. herzensteini was larger in autumn and winter, while the average mass was larger in summer and autumn. When the length is more than 15 cm, the seasonal variation of mass is larger, and the growth rate of mass is the biggest in summer. The ages of C. herzensteini ranged from 1 to 5 years old, in which individuals of 1 and 2 years old accounted for 45.15% and 40.23% of the population, respectively. The parameters of the von Bertalanffy growth equation, L∞, K and t0, were 37.85 cm, 0.28 and −0.57, respectively. The Pauly empirical formula evaluated the natural mortality to be 0.54. The total mortality, the fishing mortality, the exploitation ratio, the age of first capture and the length of first capture were 1.69, 1.15, 68.05%, 1.48 years old and 12.68 cm, respectively. In each season, only the ratio of male to female in summer was significantly different from that in 1:1 (p<0.05), and the number of females was significantly higher than that of males. 50% of the length of sexual maturity is 22.35 cm. The highest ratio of sexual maturity and the highest average coefficient of sexual maturity occur in summer. C. herzensteini mainly distributes in areas with bottom water temperature of 6.45−19.06℃, bottom salinity of 31.82−33.10 and depth of more than 50 m. Its average catch in autumn is much more than that in other seasons, which declines sharply in winter and then rises slowly. The C. herzensteini in Shandong coastal waters showed some phenomena, such as narrow length distribution, deterioration of food supply, delayed spawning period and over-exploited stock. The resources changed dramatically before and after the forbidden fishing period.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |