water Article The Horizontal Distribution of Siliceous Planktonic Radiolarian Community in the Eastern Indian Ocean Sonia Munir 1 , John Rogers 2 , Xiaodong Zhang 1,3, Changling Ding 1,4 and Jun Sun 1,5,* 1 Research Centre for Indian Ocean Ecosystem, Tianjin University of Science and Technology, Tianjin 300457, China;
[email protected] (S.M.);
[email protected] (X.Z.);
[email protected] (C.D.) 2 Research School of Earth Sciences, Australian National University, Acton 2601, Australia;
[email protected] 3 Department of Ocean Science, Hong Kong University of Science and Technology, Kowloon, Hong Kong 4 College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China 5 College of Marine Science and Technology, China University of Geosciences, Wuhan 430074, China * Correspondence:
[email protected]; Tel.: +86-606-011-16 Received: 9 October 2020; Accepted: 3 December 2020; Published: 13 December 2020 Abstract: The plankton radiolarian community was investigated in the spring season during the two-month cruise ‘Shiyan1’ (10 April–13 May 2014) in the Eastern Indian Ocean. This is the first comprehensive plankton tow study to be carried out from 44 sampling stations across the entire area (80.00◦–96.10◦ E, 10.08◦ N–6.00◦ S) of the Eastern Indian Ocean. The plankton tow samples were collected from a vertical haul from a depth 200 m to the surface. During the cruise, conductivity–temperature–depth (CTD) measurements were taken of temperature, salinity and chlorophyll a from the surface to 200 m depth. Shannon–Wiener’s diversity index (H’) and the dominance index (Y) were used to analyze community structure.