We developed a sensitive method for the detection of Nymphonella tapetis (sea spider) larvae in Manila clam Ruditapes philippinarum. The gills were removed from infected clams and lysed in 2N NaOH at 60°C. The lysate was centrifuged and the pellet was stained in 0.2% Uvitex 2B solution and observed under a fluorescent microscope. Using this method, we were easily able to enumerate the larvae. The majority of larvae were found in the gills, which were indicated as the primary site of infection for N. tepetis larvae.
2011 The Japanese Society of Fish Pathology