Journal of the Marine Biological Association of India

Volume 63 Issue 2

Rare occurrence and culture of heterotrichous ciliate, Folliculinopsis producta

P. Karthikeyan, M. Kunguma Kannika, S. R. Marigoudar and K. V. Sharma
10.6024/jmbai.2021.63.2.2192-10
Abstract

The occurrence of the marine heterotrichous ciliate in Indian waters was reported after a gap of four decades. These ciliates were recorded during a routine survey from the Chennai coast, and an attempt was also made further to rear them in captive conditions. The specimens were identified as Folliculinopsis producta after silver impregnation staining and in vivo observations. These organisms have solitary dark green colored contractile cells, which are housed into green colored semi-translucent sessile tube-like lorica of 300- 419 µm length. The total length of the cells ranged from 520 to 950 µm at a fully extended active state and 180 to 361 µm in retracted resting state. Two peristomal lobes in different sizes (104-152 µm and 172-205 µm) with intense ciliary activity in the anterior part of the cell were observed. The water quality parameters such as salinity of 30±1 psu, temperature of 28±2 °C, pH of 8.1±0.2, and dissolved oxygen of 6.0±1.5 mg/L were identified as optimum for the growth of F. producta in captive conditions. They were fed with live feed consisting of bacteria, microalgae Isochrysis galbana and diatom Thalassiosira subtilis. The swarming of planktonic juveniles was observed in 3 days after the addition of the combined diet. The free swimming juveniles were settled in the substratum after six h to 48 h. Subsequently, offspring populations ranging from 2000 to 5000 individuals/ml in a school were observed for ten days. The swarm of juveniles was appeared on the water surface and are  characterized by their phototactic movement. The offspring’s length ranged from 98-170 µm during free-swimming stage, 244-290 µm during the settlement stage. Later they developed lorica. Thus the present study provides baseline scientific insights as this will go a long way in furthering research on their biology and its role in the marine environment.

Keywords

Marine ciliate, bottle animalcule, culture, optimization, feeding

Date : 20-10-2021