Planktonic larvae are the necessary stages during the growth and development of many fishery species, such as shellfish, benthic fish, polychaete in the Huanghe River Estuary adjacent waters. Seasonal studies on the planktonic larvae community were carried out for biodiversity and bio-resource protection researches in the region. The larvae samples were collected from the vertical hauling of a mesh size 0.160 mm plankton net onboarding of six cruises during April 2019, June 2019, and August 2019, November 2019, January and April 2020 in the sea. Of the 16 planktonic larvae identified, 87% groups were meroplankton. The community diversity index (H') showed higher in June and August than in November and January. For the study region, the dominant organisms of planktonic larvae were bivalve larvae, nauplii, gastropoda larvae, polychaeta larvae, copepodite larvae, auricularia larvae. But the composition of dominant species varied with seasons, with the highest seasonal turnover rate (67%) from April to June, only bivalve larvae and nauplii dominated the planktonic larvae community for all seasons. Total planktonic larvae abundance reached the highest in November, the lowest in January. The planktonic larvae had their high abundance mostly near the estuaries of the Huanghe River and the Xiaoqinghe River, and in the middle part of Laizhou Bay. By cluster analysis, three assemblages of communities were differentiated based on the family compositions and their abundance at each station of six surveyed months. The representative species for monthly cluster groups were nauplii for spring (April) and winter (January) groups, bivalve larvae for summer-autumn (June to November) group. The station cluster groups overlapped geographically with the same representative species (bivalve larvae and nauplii). From statistical analysis of MANOVA and ANOSIM, biodiversity index, abundance, similarity among cluster groups presented significantly different among measured months, but stations, suggesting a seasonal variation for planktonic larvae community. Bio-environment multiple regression analysis showed that the combination of water temperature and zooplankton abundance had the most effects on the planktonic larvae community.
| 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 |