Genetic connectivity of the widespread hydrozoan Aglantha digitale from sub-Arctic to central Arctic regions

• Main Author: Tilvaldyeva, Leili
• Format: Thesis
• Language: unknown
• Published: 2021
• Subjects: Arctic; Arctic Ocean; Chukchi; Chukchi Sea; Greenland; Svalbard
• Online Access: https://epic.awi.de/id/eprint/56627/; https://hdl.handle.net/10013/epic.4b1c132b-016e-44f7-9425-3a94b0b10d3b

Aglantha digitale is a very widespread species found in the northern seas and northern parts of the Atlantic and North Pacific oceans, ranging from about 35N into the Arctic Ocean. A. digitale demography is tightly coupled with the distribution of warm Atlantic water, which could indicate that Atlantification can manifest in pushing the species poleward. The strengthening of the Atlantic water inflow into the Arctic may become very important for the polar pelagic ecosystems. The main objective of this study is to evaluate genetic connectivity of the widespread hydrozoan Aglantha digitale from sub-arctic to central arctic regions, to investigate the genetic structure and connectivity between populations from different geographical locations and to potentially detect different A. digitale lineages in various localities. A. digitale samples were collected at four separate localities: Svalbard, Southwest Greenland, the Chukchi Sea and the Central Arctic Ocean. These localities will help us understand whether genetic connectivity exists throughout the Arctic Ocean. The Qiagen and Chelex methods were used for the DNA extraction. DNA products were amplified using the Polymerase Chain Reaction using universal Folmer Primers and sequenced to obtain a 658 bp COI fragment. After sequence editing, the genetic distances were inferred using the Neighbour-Joining method, using the MEGA X software, with 2000 bootstrap replicates. A haplotype network was created using the PopART software to indicate the relationships between the identified haplotypes. The Neighbor-joining tree provided two clusters of A. digitale, one was influenced by the Atlantic and the other was influenced by the Pacific. Data showed that the Atlantic influence had high diversity and the Pacific influence with low diversity. These patterns of connectivity which impact population size are likely to be explained by glaciation events from the Last Glacial Maximum. The lack of haplotype diversity as presented in the Chukchi sea, could be due to the species ...