三门湾及邻近海域百陶箭虫和肥胖箭虫时空共存关系初探

群落内近缘物种如何共存是群落生态学的核心研究内容之一，三门湾及邻近海域百陶箭虫（Sagitta bedoti）和肥胖箭虫（S. enflata）的共存格局仍未知。为阐明三门湾及邻近海域百陶箭虫和肥胖箭虫共存关系，根据三门湾及邻近海域百陶箭虫、肥胖箭虫及环境调查数据，利用广义加性模型（Generalized additive models，GAMs）分析了百陶箭虫、肥胖箭虫与环境因子之间的关系，同时利用零模型检验了百陶箭虫和肥胖箭虫之间的共存格局。结果表明：百陶箭虫分布与温度、桡足类密度和浮游植物密度显著相关，肥胖箭虫与温度、桡足类密度、水深和盐度显著相关。百陶箭虫和肥胖箭虫间四季Pianka实测值与模拟值之间的差异不显著，表明百陶箭虫和肥胖箭虫之间呈随机分布状态，竞争作用和生境过滤作用共同制约二者的分布。此外，百陶箭虫和肥胖箭虫在时间和空间上发生了生态位的分化，而食物组成是否具有差异仍需进一步的研究。

Study on relationships driving the species coexistence of Sagitta bedoti and S. enflata in spatial and temporal in the Sanmen bay and adjacent waters

Study on how related species coexistence in community is a central objective in ecology. However, knowledge of coexistence pattern of Sagitta bedoti and S. enflata in the Sanmen bay and adjacent waters remaining poorly known. Two species of S. bedoti and S. enflata with environmental factors were sampled, aiming to elucidate relationships that drive the coexistence, on August and November of 2019, April and December of 2020, respectively. The Generalized Additive Models(GAMs) was used to analyze the relationships between species and environmental influences. The results indicated that S.bedoti was significantly correlated with temperature, the density of copepods and the density of phytoplankton. And S. enflata was significantly correlated with temperature, the density of copepods, water depth and salinity. The null model was used to test the coexistence pattern between S.bedoti and S. enflata. It showed that the observed Pianka indexes have no significant difference with simulated values between S.bedoti and S. enflata communities. It was suggested that a random distribution between S.bedoti and S. enflata communities, with competition and habitat filtering effects restricted their distribution. In addition, ecological niche differentiation of S.bedoti and S. enflata happened in temporal and spatial. Whether there was difference in food composition still need further study.