Soumabrota Poddar
Visva-Bharati, India
Title: Mutualistic association of fish ectoparasite Argulus bengalensis Ramakrishna (1951) with bdelloid rotifer Philodina roseola Ehrenberg (1832) - A strategy for its existence
Biography
Biography: Soumabrota Poddar
Abstract
Argulosis is known to cause large scale mortality of fish in various parts of the world. Although different control measures have been adopted against this disease, but none of those are found to be full proof and parasitaemic recurrence is an obvious because of non incorporation of the parameters of life cycle and development into the management protocol. While investigating embryonic development of the parasite of Argulus bengalensis an interesting phenomenon came to our notice that the egg stage of the parasite is intimately associated with an another organism. Under both laboratory & field conditions it has been observed that a day after egg laying, the rotifer Philodina roseola colonize and exhibit active feeding on the egg jelly. Mechanical removal of the rotifers from the egg strips resulted in complete (100%) failure in hatching inspite of full term embryonic development, while the eggs in rotifer infested condition hatched successfully. The present study thus approves a service-resource mutualistic relationship between A. bengalensis and P. roseola. In this relationship the rotifer renders service to the parasite through removing solidified jellly coat and getting nutritional benefit from it. It is proved that this mutualism is obligatory to Argulus but facultative to the rotifer. In corroboration with the relationship of Philodina spp. with other species the evolution of mutualism between these two organism is apprehended as a transformation of a parasitic relationship into mutualism. An intervention in this relationship may offer a definite clue for management of this parasitic infestation