Extreme Sensitivity of Hurter's Spadefoot Toad (Scaphiopus hurterii) Tadpoles to Suspended Particulates of Finely Ground and Powdered Rations

Abstract

Herein we report the high mortality of larval Hurter's spadefoot toad (Scaphiopus hurterii) tadpoles when fed dry powdered feeds. The evidence implies that dry powders remain suspended in the water column where they enter and clog the filtering apparatus of the tadpoles. When the same foods were wetted to a paste and dropped into the aquaria as a moist pellet, the ration fell directly to the substrate and did not become suspended in the water column. Mortalities of tadpoles fed dry powdered rations were severe, whereas mortalities when fed wetted feed were inconsequential. We recommend that that rations made of ground or powdered components not be fed unless first wetted. Further, we speculate that sediment and siltation of natural waters may contribute to amphibian losses via the same mechanism.