Nobody in This Pond Is Late
a frog changes, an axolotl never does, and both of them are grown-ups — read-aloud science for four to eight, with every source kept on the page where the grown-up can find it
A lily pad is a leaf that floats
Underneath the leaf, the water is full of animals.
Some of them are little now. All of them are busy growing up.
They are not all doing it the same way.
That is not a problem. That is the pond.
This zine follows one measured thing and does not wander from it: how long it takes to grow up in a pond, and what the measurements say about the idea of being behind.
Everything in the large type is true and sourced. Everything in these boxes is where it came from — species names, figures, the papers, and the places the evidence runs out. You should not have to leave the page to answer “is that really true?”
This frog used to be a tadpole
She had a tail. She had no legs at all.
She breathed under the water, the way a fish does.
Then her back legs came. Then her front legs came. Then her tail got smaller and smaller until it was gone.
Now she has lungs. Now she sits on the leaf.
She changed her whole body. That took a long time, and it was hard work.
This is metamorphosis, and it is a genuine rebuilding rather than a growth spurt: gills to lungs, a herbivorous gut to a carnivorous one, a swimming tail resorbed for limbs.
It is worth saying to a child that it is hard, because the next spread is about an animal who does not do it — and if the frog's route sounds effortless here, the axolotl will read as the one who failed at something easy.
This axolotl is a grown-up
He has feathery pink gills that stick out around his head, like a crown.
He has a tail for swimming. He never walked out onto the land. He never will.
He is not a baby. He is not waiting. He is not late.
He is a whole grown-up axolotl. He is a grown-up who stayed in the water.
That is his way. It always was.
The axolotl (Ambystoma mexicanum) is paedomorphic: it keeps larval features — external gills, tail fin, an aquatic life — and breeds in that body. Crowner, Khatri, Blichmann and Voss put it exactly: axolotls “express ancestral juvenile traits in the adult stage of life.”
The IUCN's own Red List assessment says the same in passing, which is the sentence we would point a doubting adult at: “It is a paedomorphic species, living permanently in water, and does not undergo complete metamorphosis.” That is a description of an adult, not of a delay.
One honest complication, kept out of the large type. Axolotls retain the capacity to metamorphose and can be pushed through it with thyroid hormone in a laboratory. They do not do it on their own. We have left this out of the read-aloud deliberately, because “he could if you made him” is the exact idea this spread is written against.
They are all one family
The axolotl has cousins.
Some of his cousins do change. They lose their gills and walk out onto the land.
Some of his cousins never change, the way he never changes.
And some of them do both.
They live right next to each other. They are still one family.
Nobody has to change the same way to belong to the same family.
Everson et al., PNAS 2021
This is the strongest thing in the zine, and it is a result rather than a sentiment. Everson and colleagues sampled the North American tiger salamander complex — the axolotl's own group — across its range in PNAS (2021). The complex holds populations that undergo metamorphosis, populations that forgo it and stay aquatic, “and those that do both.”
They then looked at whether that difference splits the family. It does not. The genetic clusters they found “often contain a mixture of paedomorphic and metamorphic taxa,” and their analyses show gene flow between adjacent metamorphic and paedomorphic populations — animals with different developmental routes living side by side and interbreeding.
Their conclusion is that geography has done more to divide these salamanders than developmental strategy has. The route through childhood is not what sorts them.
Some tadpoles are quick. Some take twice as long.
In a hot desert, there is a pond that comes when it rains and dries up again.
The tadpoles there have to hurry.
Some of them grew all the way up in eight days.
Some of them, in the very same desert, took sixteen. That is twice as long.
Both of them grew up. Both of them are frogs.
Nobody counted the slow ones as late.
Newman, Ecology 1989
Newman, in Ecology (1989), measured Couch's spadefoot (Scaphiopus couchii) in desert ponds of varying duration. With sufficient food, larvae developed in eight to sixteen days — a range, in one species, in one place.
A correction we made on the way. The figure that circulates is a flat “eight days — the shortest of any North American amphibian.” Eight is the floor of a range, not the fact. We went to Newman because a single number is exactly the shape of thing that loses its range in retelling, and the range is the whole point of this spread.
How fast is not only up to the tadpole
Some scientists wanted to know what makes a tadpole hurry.
So they took a tank of water with tadpoles in it, and they let the water get lower. A little bit each day.
The tadpoles could feel the water going down.
And they hurried.
The faster the water went down, the faster they hurried. It was not like a switch that clicks on. It was more like a dial, turning.
Denver, Mirhadi and Phillips, Ecology (1998), reduced water in aquaria at a controlled rate. Tadpoles “showed significant acceleration of metamorphosis,” and — the part worth keeping — “the developmental acceleration depended on the rate of reduction of the water level; i.e., tadpoles exhibited a continuum of response.”
A different spadefoot from the last spread. This is the western spadefoot, Scaphiopus hammondii; the eight-to-sixteen-day figures were Couch's spadefoot, S. couchii. Two related species, two studies, and we are not merging them into one animal.
The cue was not what the authors expected either. It was not chemical, and not other tadpoles. It “appears to be related to the reduced swimming volume” — and when the water is low, tadpoles eat less.
Then they put the water back
Here is the part we like best.
The scientists filled the tanks back up.
And the tadpoles slowed back down. They started growing again. They stopped hurrying.
So how fast a tadpole grows up was never only about the tadpole.
It was about the tadpole and the pond. Together.
And of those two, the pond is the one a grown-up can change.
Same paper. Refilling the aquaria at various points after the drawdown began “resulted in restoration of body mass and a tendency to decelerate metamorphosis.” The hurrying was not a fixed trait switched on for good. It tracked the conditions, in both directions.
This is the spread the whole zine is built to arrive at, and it is the reason we would rather hand a caregiver a tadpole than a milestone chart. A rate of development was read here as information about an environment — and the environment is the half that can be altered.
Said plainly, and held there: this is a measurement about spadefoot toads. It is not a finding about children, and we are not going to dress it as one. What it is good for is loosening the assumption that a pace is a property of the small creature going at it.
Where the argument about people actually lives — not here. Stimpunks makes it on human evidence, at Developmental Pace: a why sheet, a glossary entry, and a printable broadside made for the meeting where a child is about to be told they are behind. Its sentence is sharper than any of ours: “Behind” is information about the ruler, not about the learner.
The ones who hurried came out smaller
Hurrying worked. The quick ones got out before the pond dried up. That is a good thing, and it saved them.
But hurrying was not free.
The tadpoles who hurried came out smaller than the ones who took their time.
Two different sets of scientists found this. One watched real ponds outside. One used tanks indoors. They both found the same thing.
So going fast is not better. It just costs something different.
Denver, Mirhadi and Phillips (lab, 1998): “Accelerated development resulted in smaller size at metamorphosis.” Newman (field, 1989): rapid development maximised the chance of finishing before the pond dried, “but resulting in small size at metamorphosis.”
Two study designs, two species, one cost — which is a good deal more than either paper establishes alone. Newman also found the accelerated metamorphs emerged with relatively smaller hindlimbs.
Why this spread exists at all. A zine that stopped at spread eight would have argued that slow is fine, which is true and only half of it. The other half is that speed has a price nobody bills the fast child for either. Both halves belong to the same measurement, and leaving out the second one would have been the more comfortable edit.
Nobody in this pond is late
The frog changed everything about herself.
The axolotl never changed at all, and he is a grown-up too.
Some tadpoles took eight days. Some took sixteen. Some of their cousins take a whole winter, and then another one.
The pond does not have one right way to grow up. It never did.
Fast is not better. Slow is not late.
You are growing up in your own pond, at your own speed, and you are not behind.
We love you down to your star stuff.
“A whole winter, and then another one” is the loosest sentence in this zine and it is deliberately vague. American bullfrog tadpoles are widely reported overwintering for one to three years, with the figures scattering badly across sources — some populations metamorphose in under four months. We could not resolve it to a primary we were willing to print, so it stays a soft comparison in the read-aloud and gets no number anywhere.
Everything else in the large type on this page is carried by the four papers in the colophon.
Not:
How fast a tadpole grows up was never only a fact about the tadpole. It was a fact about the tadpole and the pond, together — and the pond is the half a grown-up can change.
What is the water level in the room this child is growing up in, and who has a hand on the tap?
When you call a pace slow, what are you measuring it against, and who chose that?
Where have you paid the cost of hurrying and had nobody count it?
Which grown-ups in this child's life are the ones who left the water, and which ones stayed?
For Lilypad Library
This zine exists because of Kiersten Case and Lilypad Library, the low-stimulation puppet series she created for neurodivergent kids, which the Stimpunks Foundation is proud to fiscally sponsor. The frog-and-axolotl pairing is theirs, not ours — the show put those two animals side by side, and this zine is what happened when we went to look up whether the biology underneath that pairing was as good as it looked. It was better.
The show's characters have names. We have not used them here, because they are Kiersten Case's to lend and this page was not the place to assume. Nothing in this zine should be read as coming from the show, or as speaking for it.
Sources
The eight-to-sixteen days. Robert A. Newman, “Developmental Plasticity of Scaphiopus couchii Tadpoles in an Unpredictable Environment,” Ecology 70(6), 1775–1787 (1989). Source of the larval-period range on spread six and of the field half of the size cost on spread nine.
The drying pond, the continuum, and the refill. Robert J. Denver, Nooshan Mirhadi & Marnie Phillips, “Adaptive Plasticity in Amphibian Metamorphosis: Response of Scaphiopus hammondii Tadpoles to Habitat Desiccation,” Ecology 79(6), 1859–1872 (1998). Source of spreads seven and eight and of the laboratory half of spread nine, including the quoted continuum of response, the restoration-of-body-mass result, the reduced-swimming-volume cue, and “Accelerated development resulted in smaller size at metamorphosis.” Read at full text.
The axolotl. Aaron Crowner, Shivam Khatri, Doris Blichmann & S. Randal Voss, “Rediscovering the Axolotl as a Model for Thyroid Hormone Dependent Development,” Frontiers in Endocrinology 10, 237 (2019) — the ancestral juvenile traits in the adult stage of life wording, and the induced-metamorphosis complication kept in the spread-four grown-up box.
The family. Kathryn M. Everson, Levi N. Gray, Angela G. Jones and colleagues, “Geography is more important than life history in the recent diversification of the tiger salamander complex,” PNAS 118 (2021), doi:10.1073/pnas.2014719118. Source of spread five and Figure 1. Read at the abstract only — the publisher returned 403 to us and we reached the record through Europe PMC. Every phrase quoted on that spread is from the authors' own abstract; we have not read their methods, and a reader who wants the sampling design will have to go further than we did.
The conservation status. IUCN SSC Amphibian Specialist Group. 2020. Ambystoma mexicanum. The IUCN Red List of Threatened Species 2020: e.T1095A53947343. Assessed 23 October 2019; Critically Endangered A2abce, on an observed decline estimated at more than 80% over three generations (16.5 years). Source of the paedomorphic species, living permanently in water sentence quoted on spread four. Read at full text.
And the hopeful one. Alejandra G. Ramos, Horacio Mena, Diana Schneider & Luis Zambrano, “Movement ecology of captive-bred axolotls in restored and artificial wetlands: Conservation insights for amphibian reintroductions and translocations,” PLOS ONE (2025) — released captive-bred axolotls that were recaptured having gained weight, suggesting successful adaptation, in the same breath as two axolotls were lost to avian predation. Both halves, as the authors wrote them.
What we cut, and why
A number that is repeated everywhere and is not in the assessment. Secondary accounts of the axolotl's decline commonly run a density series ending “35 individuals per square kilometre in 2017.” The Red List assessment carries the earlier figures — 6,000 in 1998, 1,000 in 2004, and 100 in 2008, that last one explicitly unpublished data — and it says nothing about 35. What it says about 2017 is starker and differently shaped: monthly sampling at Xochimilco through that year did not record the species at all. We are printing the assessment's own sentence and not the tidier number, and we would not have caught the difference without going to the document.
The bullfrog's two winters is discussed in the spread-ten grown-up box: reported, unresolved, and therefore given no figure.
The axolotl a child meets in this zine is nearly gone from its lake, and we have kept that out of the large type on purpose. A four-year-old being read to at bedtime is owed the animal before the obituary. The grown-up holding the book is owed the fact, which is why it is here: the only site with records in recent years is Chapultepec Lake — artificial, cement-lined, in a city park — where released individuals seem to be breeding. The animal that never leaves the water is now breeding in the pond we poured for it.
What this deliberately does not re-argue
Stimpunks already owns the argument about people, and this zine does not restate it. Developmental Pace exists as a why sheet, a glossary entry and a printable broadside, built on human evidence and written for the meeting where a child is about to be told they are behind. Its definition — the rate at which a person arrives … and it varies enormously between people, and within one person across different domains — and its “behind” is information about the ruler are the sentences this zine is standing next to rather than reaching for. The glossary’s own refusals overlap with spread eleven deliberately: it says pace is not simply slower is better, that pace is neither virtuous nor flawed, and that survivability depends on context — which is precisely why spread nine prints the cost of hurrying instead of stopping at spread eight.
No. 34 owns “slow” in this collection. Two Hundred Years Before You’re Grown follows the Greenland shark to sexual maturity at about 156 years and then turns the finding over: slow is viable in an environment that permits it and lethal in one that does not. This zine is its other half, and its opposite in shape — not one animal that is slow, but a pond with no shared schedule at all, where the pace moved when the water did and moved back when it returned. It is also the first piece here written for the child rather than about them.
No. 61 owns neoteny here — Jorn Bettin's inversion, retained neoteny as distributed adaptive capacity rather than developmental lag. That is an argument about people and about groups. This zine does not restate it and does not lean on it: it stays with four salamanders and two spadefoot toads, and lets the reader carry whatever they carry. No. 87 owns the same-trait-two-rooms argument, and The Difference-First Frame owns the reasoning behind reading variation before deficit.
A rhyme, not a proof. We are not claiming a tadpole is like a child. We are pointing at a set of measurements in which a rate of development turned out to be a fact about conditions as much as about the animal — reversible when the conditions reversed, and costly when it was rushed.