Experiment on the functional response of non-indigenous crab Hemigrapsus takanoi across seasons and temperatures in the Baltic Sea

We examined the functional response of the Japanese brush-clawed shore crab ( Hemigrapsus takanoi ) towards blue mussels ( Mytilus sp.) across four seasons for an ambient and +6 °C future warming scenario in the Baltic Sea. The experiment was carried out as a laboratory experiment at the GEOMAR Helmholtz Centre for Ocean Research Kiel. Crabs were sampled in the innermost part of the Kiel Fjord, Germany (54°19′44.8″ N, 10°08′55.5″ E) between Summer 2021 and Spring 2023 during the respective season. The experimental design used a fully factorial approach, examining the functional response across two temperatures, two sexes, and eight prey densities (1, 2, 4, 6, 8, 16, 32, 64) across four seasons. Each crab was subjected to a pre-experiment 48-hour starvation period and then exposed to a fixed number of mussels for a 72-hour feeding trial. The number of mussels consumed was recorded, providing data on the predatory impact of H. takanoi under varying temperature scenarios and across seasons.

本研究针对波罗的海海域，在当前环境温度与+6℃的未来增温情景下，于四个季节维度中探究了日本毛刷爪滨蟹（Hemigrapsus takanoi）对贻贝属（Mytilus sp.）的功能响应（functional response）。本实验于基尔亥姆霍兹海洋研究中心（GEOMAR Helmholtz Centre for Ocean Research Kiel）开展室内受控实验。实验所用滨蟹于2021年夏季至2023年春季期间，在对应季节从德国基尔峡湾最内侧海域（北纬54°19′44.8″，东经10°08′55.5″）采集获取。实验设计采用完全析因设计，设置两个温度水平、两个性别梯度以及八种猎物密度（1、2、4、6、8、16、32、64），覆盖四个季节开展功能响应探究。每只滨蟹均先经过48小时的预实验禁食处理，随后被放置于固定数量的贻贝中开展为期72小时的摄食试验。本研究记录了被摄食的贻贝数量，由此获取日本毛刷爪滨蟹在不同温度情景及季节变化下的捕食影响数据。