# What animal grows the most from birth to maturity? **URL:** \ **Category:** Factual Questions\ **Created:** [May 31, 2018, 6:20am UTC](https://boards.straightdope.com/t/what-animal-grows-the-most-from-birth-to-maturity/815176 "2018-05-31T06:20:30Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![Enola\_Gay](https://avatars.discourse-cdn.com/v4/letter/e/3ab097/32.png) [@Enola\_Gay](https://boards.straightdope.com/u/Enola_Gay)\ **Post date:** [May 31, 2018, 6:20am UTC](https://boards.straightdope.com/t/what-animal-grows-the-most-from-birth-to-maturity/815176/1 "2018-05-31T06:20:30Z")
The obvious answer IMO would be the red kangaroo, which starts out life the size of a bean, then at maturity weights 60+ lbs. HOWEVER, the joeys spend 9 months in the pouch, which IMO is another type of womb. SO which animal grows the most from living outside of the mother (but can still have assistance from the mother) to maturity? ETA I am talking percentage-wise. So even though the blue whale can gain 250,000 lbs from birth to maturity, another animal, even an insect, might grow more proportionally/exponentially than that. What creature is that? ---
**Author:** ![lingyi](https://avatars.discourse-cdn.com/v4/letter/l/d2c977/32.png) [@lingyi](https://boards.straightdope.com/u/lingyi)\ **Post date:** [May 31, 2018, 7:07am UTC](https://boards.straightdope.com/t/what-animal-grows-the-most-from-birth-to-maturity/815176/2 "2018-05-31T07:07:29Z")
Off the top of my head, maybe a panda? Plus they’re soooooo cute! 😃 ---
**Author:** ![MrDibble](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mrdibble/32/114_2.png) [@MrDibble](https://boards.straightdope.com/u/MrDibble)\ **Post date:** [May 31, 2018, 7:09am UTC](https://boards.straightdope.com/t/what-animal-grows-the-most-from-birth-to-maturity/815176/3 "2018-05-31T07:09:24Z")
[Ocean Sunfish](https://en.wikipedia.org/wiki/Ocean_sunfish#Lifecycle) are often considered contenders here - from 2.5mm as fry to 3.3m+ as adults - or “60 million times their birth size” (by which I guess they mean weight) Other contenders include big jellyfish, big crabs and tapeworms, all of which have microscopic larvae but meter+ adults. I’d also like to nominate the anti-example: [_Pseudis paradoxa_](https://en.wikipedia.org/wiki/Pseudis_paradoxa), a frog that’s around a quarter the size of its tadpole. ---
**Author:** ![obbn](https://avatars.discourse-cdn.com/v4/letter/o/d6d6ee/32.png) [@obbn](https://boards.straightdope.com/u/obbn)\ **Post date:** [May 31, 2018, 8:20am UTC](https://boards.straightdope.com/t/what-animal-grows-the-most-from-birth-to-maturity/815176/4 "2018-05-31T08:20:03Z")
The answer most definitely would be my ex wife. ---
**Author:** ![kanicbird](https://avatars.discourse-cdn.com/v4/letter/k/5f8ce5/32.png) [@kanicbird](https://boards.straightdope.com/u/kanicbird)\ **Post date:** [May 31, 2018, 11:40am UTC](https://boards.straightdope.com/t/what-animal-grows-the-most-from-birth-to-maturity/815176/5 "2018-05-31T11:40:02Z")
Only mammals are ‘born’, most others are hatched. Do you want to exclude them? Or how would you could those who are hatched, the moment they are passed outside of the mother, or the breaking open of the shell? And you have weird stuff like the seahorse happening where the father had a roll the development stage. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [May 31, 2018, 12:28pm UTC](https://boards.straightdope.com/t/what-animal-grows-the-most-from-birth-to-maturity/815176/6 "2018-05-31T12:28:40Z")
We did this before. For mammals the Red Kangaroo might be the winner. But for all animals, IIRC it would be the Giant Clam. [And a quick search reveals the previous thread](https://boards.straightdope.com/sdmb/showthread.php?t=579499&highlight=Giant+Clam). ---
**Author:** ![MrDibble](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mrdibble/32/114_2.png) [@MrDibble](https://boards.straightdope.com/u/MrDibble)\ **Post date:** [May 31, 2018, 12:42pm UTC](https://boards.straightdope.com/t/what-animal-grows-the-most-from-birth-to-maturity/815176/7 "2018-05-31T12:42:13Z")
> [@kanicbird](#): > > Only mammals are ‘born’ This is highly inaccurate - _lots_ of other genera have species which practice [viviparity](https://en.wikipedia.org/wiki/Viviparity) : scorpions, cockroaches, velvet worms, sharks, frogs, snakes, and lizards, at least. ---
**Author:** ![Enola\_Gay](https://avatars.discourse-cdn.com/v4/letter/e/3ab097/32.png) [@Enola\_Gay](https://boards.straightdope.com/u/Enola_Gay)\ **Post date:** [May 31, 2018, 6:07pm UTC](https://boards.straightdope.com/t/what-animal-grows-the-most-from-birth-to-maturity/815176/8 "2018-05-31T18:07:06Z")
> [@kanicbird](#): > > Only mammals are ‘born’, most others are hatched. Do you want to exclude them? Or how would you could those who are hatched, the moment they are passed outside of the mother, or the breaking open of the shell? And you have weird stuff like the seahorse happening where the father had a roll the development stage. I’d say once the organism is independent of a pouch, egg, uterus, etc. From that size to full grown.