Journal of the Marine Biological Association of India

Diversity, distribution and polymorphism of loricate ciliate tintinnids along Hooghly estuary, India

 

Volume 58 Issue 2

Dibyendu Rakshit and Santosh Kumar Sarkar

10.6024/jmbai.2016.58.2.1926-10

Abstract

The choreotrich ciliate tintinnid (Ciliophora: Tintinnida) community was assessed from nine sampling sites (n=108) along the Hooghly estuary, east coast of India during June 2012 to May 2013. A total of 32 tintinnid species (3 core, 12 seasonal and 17 perennial species) were recorded from agglomerated form, dominated by Tintinnopsis sp., contributing ~62 % of total tintinnid population. The community was predominated by Tintinnopsis beroidea followed by Tintinnidium primitivum , Leprotintinnus simplex , Tintinnopsis tubulosa and T. minuta. The maximum abundance of tintinnids (1287 ind. L-1) and species diversity (H´= 2.87) was recorded during post monsoon season (January) coinciding with high concentration of diatoms (6720 cells L-1). In contrast, both numerical density (55 ind. L-1) and species diversity (H´= 1.21) values were minimum during monsoon in association with low phytoplankton density (2200 cells L-1). The large size tintinnids mainly composed of Codonellidae (55%) and Tinntinnidiidae (30%) were the most dominating in this estuarine ecosystem. The result of ANOVA showed significant variation between species abundance and months (F= 2.21; P≤ 0.041). K-dominance curves were plotted against log rank k , showed species dominance over the investigated sites. The CCA map revealed a clustering of core species with chl a and dissolved oxygen which were found to be the most important factor controlling the distribution and seasonal patterns of tintinnids. The changes in lorica morphology for three dominant tintinnids are directly related to their unique adaptive strategies to the variations of temperature and salinity. The study provided exhaustive information of microzooplankton which enhances our understanding of their interactions in a tropical estuarine system and of immense importance in the context of maintaining its ecological and economic stability.

 

Keywords

Tintinnid, polymorphism,seasonal variations, loricate ciliate, Hooghly estuary

 

Date : 30-12-2016