American toad American toad The American toad ("Anaxyrus americanus") is a common species of toad found throughout the eastern United States and Canada. It is divided into three subspecies—the eastern American toad ("A. a. americanus"), the dwarf American toad ("A. a. charlesmithi"), and the rare Hudson Bay toad ("A. a. copei"). Recent taxonomic treatments place this species in the genus "Anaxyrus" instead of "Bufo". The eggs of the American toad are laid in two strings and can hatch in 2–14 days. When hatched the tadpoles are recognizable by their skinny tails in relation to the size of their black bodies. They may
Crustacean larva (lecithotrophy). In species with normal development, eggs are roughly 1% of the size of the adult; in species with abbreviated development, and therefore more yolk in the eggs, the eggs may reach 1/9 of the adult's size. The post-larva of shrimp is called "parva", after the species "Acanthephyra parva" described by Henri Coutière, but which was later recognised as the larva of "Acanthephyra purpurea". In the marine lobsters, there are three larval stages, all similar in appearance. Freshwater crayfish embryos differ from those of other crustaceans in having 40 ectoteloblast cells, rather than around 19. The larvae show abbreviated development,