01-05 December 2025
INCOIS, Hyderabad, India.
| Abstract Submission No. | ABS-06-0142 |
| Title of Abstract | Exploring the Distribution and Community Structure of Microzooplankton in the Indian Ocean during spring inter-monsoon: Insights from Surface and Chlorophyll Maxima Samples |
| Authors | SARUN T P*, JAGADISH S PATIL, PRANOY PAUL |
| Organisation | CSIR - National Institute of Oceanography Goa |
| Address | SAD 18 , NIO Colony , Donapaula Panaji, GOA, India Pincode: 403004 E-mail: saruntpsarusme143@gmail.com |
| Country | India |
| Presentation | Oral |
| Abstract | Microzooplankton (MZP) represent the most diverse group within the marine ecosystem, serving as the vital link between traditional and microbial food webs while playing a pivotal role in the energy flow and nutrient cycling. The present study addresses the distribution and community structure of MZP across 22 stations in different regions of the Indian Ocean (IO) ⿿ northeastern Indian Ocean (NEIO), equatorial Indian Ocean (EIO), southeast (SETIO), and southwest (SWTIO) Tropical Indian Ocean. Samples were collected from both surface waters and the chlorophyll maxima (Cmax), which demonstrated significant regional depth variations ranging from 45 to 135 meters. Cmax was found to be shallower in the NEIO (43-75 m) compared to the SETIO (115-135 m). In this study, MZP were classified into Copepod nauplii, Heterotrophic dinoflagellates (HTD), Tintinnid (Loricate ciliates), Aloricates, Foraminifera, Pheodaria, and Radiolarians. Altogether, 271 MZP species were recorded, among them 135 were radiolarians, 107 were tintinnids, and 29 were HTD. Radiolaria and tintinnids were highly diverse, evidenced by the Shannon-Wiener diversity indices of 2.57 ± 0.20 and 2.54±0.36, respectively. MZP abundance varied between 7.2 and 107.8 ind/L. The MZP abundance was greater in the Cmax (Avg: 59.78 ±23.32 ind/L) than in surface water (45.1 ± 23.23 ind/L). Surface water across all regions was dominated by HTD (28-69%), followed by copepod nauplii (13-22%), tintinnid (9-23%), and radiolaria (5-28%). In contrast, the community structure in the Cmax showed regional variation. In NEIO and SWTIO copepod nauplii (32% and 27% respectively) form the dominant group, meanwhile, the EIO is dominated by HTD (40%), whereas tintinnid (33.5%) in the SETIO. This study enhances our understanding of MZP community distribution in IO and contributes to ongoing research in the diversity and biogeography of microzooplankton. |
| Are you part of IIOE-2 endorsed project | no |
| Keywords | Microzooplankton, Chlorophyll maxima, Surface water, Diversity, Distribution, Indian Ocean |
| For Awards | yes |
| Date Of Birth | 01-02-1999 |
| ECSN Registration Number | IIOE2-ECSN-0123 |