THE PHENOMENA OF COLOURATION, CROWDING EFFECT AND SITE SELECTION BE HAVIOUR OF ECHINORHYNCHUS VEL (ACANTHOCEPHALA) INFECTING THE FLAT FISH, SYNAPTURA ORIENTALIS

The phenomena of colouration, crowding effect and site selection behaviour were observed in the acanthocephalid worm, Echinorhynchus veli infecting the brackish water flat fish Synaptura orientalis. The coloration was due to carotenoid pigment. Crowding effect indicated the relationship between the mass of the Worms and the density of infection; the size/weight of the Worms being inversely proportional to the number of worms per host. In E veli infection, the Worms preferred the middle region of the intestine, the mature worms occupying the anterior and the immature Worms, the posterior infection sites of the intestine.