Some observations on the division of five species of commensalic ciliates in relation to water propulsion

A study was made to understand whether there is any correlation between the physiological or morphogenetic activities of commensalic ciliates and the cycles of water propulsion of their hosts. Commonly occurring species ciliates. Boveria teredinidi, Trichodina balakrishnia, Nucleocorbula adherens, Thigmozoon fencheli and Nyctotherus marina from the hosts Teredo furcifera and Nausitora hedleyi were used. The total number and the individuals in division for each species of ciliates were noticed. The results obtained indicate that there is no correlation between the activities of these ciliates and cycles of water propulsion. The data were statistically analysed. It was found that shipworms below 8 mm. in size were not infected with these ciliates. This shows that infection takes place, not from the parent's body but from the outside water after a definite period of growth of the host. An increase in number of commensals in relation with the increase in size of the host was observed. There is a decline in numbers in the oldest hosts. The number of dividing individuals also follows the same pattern of occurrence.