GLOCHIDIAL METAMORPHOSIS OF THE FRESH-WATER MUSSEL LAMPSILIS-CARDIUM (BIVALVIA, UNIONIDAE) ON LARVAL TIGER SALAMANDERS, AMBYSTOMA-TIGRINUM SSP (AMPHIBIA, AMBYSTOMIDAE)

Larval tiger salamanders (Ambystoma tigrinum ssp.) were infected with glochidia of the freshwater mussel Lampsilis cardium in laboratory exp eriments. At 20-21 degrees C, metamorphosis occurred from 9 to 39 days , primarily between 9 and 17 days. The percentage of attached glochidi a that metamorphosed varied from 0.27 to 15.7%. Metamorphosis on the s alamanders occurred more quickly than on a known piscine host, largemo uth bass (Micropterus salmoides), but a smaller percentage of the tota l attached glochidia metamorphosed. The role of amphibians as hosts of freshwater mussels in North America has not been addressed. Recognizi ng such a relationship could have important consequences for our under standing of mussel zoogeography.