(1)the immature free-living form of most invertebrates and amphibians and fish which at hatching from the egg is fundamentally unlike its parent and must metamorphose
(2)卵からかえり、基本的に親と似ていないで変身しなくてはならないほとんどの無脊椎動物、両生類と魚の未成熟の自生形体