direct development

{{Short description|Growth to adulthood without metamorphosis}}

Direct development is a concept in biology. It refers to forms of growth to adulthood that do not involve metamorphosis. An animal undergoes direct development if the immature organism resembles a small adult rather than having a distinct larval form.{{cite journal|url=https://www.tandfonline.com/doi/abs/10.1080/00222933.2021.1895349|accessdate=March 7, 2023|title=Direct development of the bush frog Raorchestes longchuanensis (Yang and Li 1978) under laborary conditions in Southern China|journal=Journal of Natural History|pages=123–132|author1=Fang Yan|author2=Xiaolong Liu|author3=Yinpeng Zhang|author4= Zhiyong Yuan|date=May 28, 2021|volume=55 |issue=1–2 |doi=10.1080/00222933.2021.1895349|s2cid=236202923 |url-access=subscription}} A frog that hatches out of its egg as a small frog undergoes direct development. A frog that hatches out of its egg as a tadpole does not.

Direct development is the opposite of complete metamorphosis. An animal undergoes complete metamorphosis if it becomes a non-moving thing, for example a pupa in a cocoon, between its larval and adult stages.{{cite journal|title=Complete metamorphosis of insects|author1=Jens Rolff|author2= Paul R. Johnston|author3= Stuart Reynolds|doi=10.1098/rstb.2019.0063|date=August 26, 2019|pmid= 31438816|volume=374|issue=1783|journal=Philos Trans R Soc Lond B Biol Sci|pmc=6711294 }}