LAGENIDIUM CALLINECTES (COUCH, 1942) INFECTION AND ITS CONTROL IN CULTURED LARVAL INDIAN TIGER PRAWN, PENAEUS-MONODON FABRICIUS

A mycosis in larval tiger prawn, Penaeus monodon Fabricius, is describ ed for the first time from India. The hyphae of Lagenidium callinectes are contorted, irregularly branched, sparingly septate, and contain a cell wall and membrane, vacuoles, mito chondria, ribosomes, small and large vesicles, and Woronin bodies. The spores occur singly or in pai rs. The fungal mycelium may either invade and embed itself in the tiss ues, or alternatively, replace all the muscle tissues of the infected larval P. monodon. Fungus infected, untreated populations of nauplii, zoea and mysis exhibited mortalities of 5 . 33 +/- 0 . 55%, 24 . 68 +/ - 4 . 58% and 47 . 89 +/- 0 . 27%, respectively. A 0.5 ppm treatment w ith trifluralin significantly reduced the mortality of infected larval populations (i.e. 1 . 1% nauplii, 3 . 28% zoea and 5 . 21% mysis mort ality). Lagenidium sp. exhibited growth in potato dextrose agar medium and in Sabouraud's agar at 28 degrees C.