The Platypus: Nature’s Weirdest Creature – Part 3 (Final Part)

Hello again.... Welcome to the final part of my platypus series! Finally I am ending it...

If you haven’t read them yet, make sure to check out Part 1 and Part 2 first: → The Platypus: Nature’s Most Exceptional Creature [Part 1] → The Platypus: Nature’s Most Exceptional Creature [Part 2]

In the first two parts, we talked about how the platypus lays eggs, feeds milk without nipples, has venomous spurs, hunts with electricity, and has all those crazy features. Now in this last part, we’re wrapping everything up with how it stays warm in cold water, how it raises its babies, its important role in nature, and why we really need to protect this amazing animal. Let’s dive in!

7. UV Light Reflection

The platypus has another super weird trick: its fur glows under ultraviolet (UV) light! Scientists discovered this around 2020 when they shone UV lights on museum specimens — the brown fur suddenly lit up in a bright blue-green glow. It's called biofluorescence (not the same as glowing like a firefly — it needs UV light from the sun or moon to work).

Why does it glow? No one knows for sure yet, but here are the best guesses:

Camouflage in dim light — at dawn, dusk, or in shady rivers, the glow might help it blend in with water or plants that also reflect UV. Talking to each other — maybe males and females spot each other better at night using the glow. Warning predators — it could signal "I'm not tasty" or "stay away" (especially since males have venom!). Or maybe it's just a side effect of the fur chemicals with no real purpose.

This glow isn't super bright — you need a UV light to see it clearly — but it's rare in mammals. Other animals like flying squirrels, wombats, and some opossums do it too. For the platypus, it fits perfectly with its nocturnal, low-light lifestyle in murky rivers. It's one more thing that makes this animal feel like it came from another planet!

8. Weird Chromosomes and DNA

The platypus's genes are as strange as the rest of it. Most mammals have simple sex chromosomes: females are XX, males are XY. But the platypus? Males have 10 sex chromosomes (5 X and 5 Y), and females have 10 X's — arranged in a big chain during cell division. This setup is more like birds or some reptiles than normal mammals!

Recent research (up to 2025) shows:

A special gene called AMHY (a version of anti-Muellerian hormone) on one of the Y chromosomes decides if the baby becomes male. This gene changed a long time ago (over 100 million years!) and took over sex determination in monotremes.
The platypus genome is a crazy mix: it has mammal genes, but also lots of reptile-like and bird-like ones.
Egg-laying genes (like vitellogenin for yolk) are active — most mammals turned them off long ago.
Venom genes look a lot like snake venom genes (even though they're not related).
Electroreception genes are extra strong to support the bill's superpower.

This mix proves the platypus is a living "missing link" — it split from other mammals super early (around 166–220 million years ago) and kept many ancient features. Scientists love studying its DNA because it helps us understand how mammals, birds, and reptiles evolved from shared ancestors. It's like reading an old family history book!

9. Belly and Body Structure

The platypus's body is built like a perfect swimming machine. Its shape is streamlined (torpedo-like) to cut through water easily, with short legs, a flat bill, and a wide, flat tail that acts like a rudder and stores fat for energy.

Key cool parts:

Fur — super dense (up to 900 hairs per square mm!), waterproof, and traps air for warmth and buoyancy. It keeps the platypus dry even after hours in cold water — better insulation than a polar bear's fur!
Webbed feet — front feet have full webbing that spreads out like flippers for powerful strokes; hind feet help steer and (in males) carry the venom spurs.
Tail — furry, not scaly like a beaver's, helps with steering and balance. It also stores fat like a camel's hump for tough times.
Skeleton — lightweight but strong bones (some denser for less floating). Legs stick out sideways (like a lizard's), with bent elbows and knees for digging burrows and twisting underwater. It even has extra "reptile-like" bones in the shoulder (interclavicle and coracoids) that most mammals lost long ago.
Belly — soft and flexible, holds the mammary patches for milk (in females), plus thick fat for insulation. The whole body is low-profile in water — only three small humps show above the surface (head, back, tail) when swimming.

This design lets the platypus dive, turn sharply, dig, and swim for hours without getting tired. It's unchanged for millions of years because it works so well!

10. Thermoregulation and Metabolism

The platypus keeps its body at about 32°C — cooler than us humans (37°C) — which saves energy in cold water. But it still stays warm thanks to:

Thick, air-trapping fur (like a built-in drysuit).
Fat layer under the skin (extra thick on belly and tail).
Smart blood flow — during dives, it sends less blood to skin and more to brain/heart/muscles.
Counter-current heat exchange in legs and tail — cold blood coming back warms up before reaching the heart.

Its metabolism is super high because it's always active (diving hundreds of times a day). It eats 20–30% of its body weight daily — that's like you eating 15–20 kg of food every day!

Diving tricks:

Holds breath up to 2 minutes (sometimes more).
Muscles full of myoglobin (stores oxygen like in whales/seals).
Heart slows way down underwater (saves oxygen).
Spleen releases extra red blood cells when needed.

This lets it hunt non-stop in cold rivers without freezing or running out of energy. Recent studies show its thyroid hormones are high, which pushes metabolism even with the lower temperature.

11. Reproductive Behavior

Platypus babies start with drama! Mating is in late winter/early spring (July–October). Males fight hard with venom spurs — wrestling underwater, trying to stab rivals to win females.

The female does all the work after:

Digs a long, complex nesting burrow (up to 20–30 meters into the bank) — hidden entrance, multiple tunnels, dead-ends, and "pugs" (mud plugs) to block predators and keep it stable.
Collects wet leaves/grass (drags with tail) for the nest — takes several nights.
Lays 1–3 leathery eggs (size of large grape) — incubates 10–14 days by curling around them with tail and belly for warmth.
Puggles hatch tiny (2–3 cm), blind, hairless — crawl to belly patches and drink oozing milk (rich + antibacterial).
Mom stays inside almost full-time for 3–4 months — only quick food trips at night. She loses lots of weight making milk.
Young leave burrow at 4–5 months — fully furred, eyes open, ready to swim/hunt.

Nesting females pick higher, farther-from-water banks for safety. Recent studies show invasive rats/mice sometimes enter burrows — a new worry for babies.

12. Ecological Role and Conservation

The platypus is a river superhero:

Eats tons of invertebrates (yabbies, larvae, shrimp) → keeps populations balanced.
Digs/probes riverbeds → mixes nutrients, helps oxygen flow, good for fish/frogs/plants.
Super sensitive to changes → if platypuses disappear, the river is in trouble (indicator species).

Status (2025–2026):

Near Threatened globally (IUCN since 2016) — declining overall, could get worse.
Vulnerable in Victoria, Endangered in South Australia.
No national threatened listing in Australia yet, but nominated.

Big threats:

Dams/weirs → block movement, change flows, dry up pools.
Drought/climate change → warmer water, less food.
Pollution (farm chemicals, plastics) → kills prey, builds up in fat.
Clearing riverbanks → no burrow spots.
Invasive predators (foxes, cats) → eat young.
Fishing traps/nets → accidental drowning.

Conservation efforts:

Restore trees along rivers for shade/cool water/burrow banks.
Monitor with cameras, eDNA (water DNA tests), citizen sightings.
Better water rules (environmental flows from dams).
Protect deep pools and clean water.

The platypus has survived millions of years, but needs our help now. Saving its rivers saves many other animals too! Talking to each other — maybe males and females spot each other better at night using the glow.

==========================================================================

Alright, platypus party is officially over!

We covered eggs, no-nipple milk, venom kicks, electric-face hunting, glowing fur, bizarre DNA, cold-water survival hacks, secret burrows, and why this little guy is basically a river health superhero.

Mind officially blown? Mine too — and it all started with one dumb late-night scroll.

Quick question before we go: Which platypus fact are you telling everyone about first? Comment below so I can see what stuck with you the most!

Thanks for hanging out with me through all three parts. You’re the real MVP.

Catch you in the next post — promise it’ll be just as fun (and probably just as random).

Sources & Credits

This three-part platypus blog series was written with love (and a lot of curiosity) by me, Tonmoy. Almost everything came from reading, watching, and cross-checking reliable scientific and educational sources. Here are the main places I drew information from:

Key Sources Used Across All Parts

Australian Platypus Conservancy – platypus.org.au (excellent fact sheets on biology, behaviour, conservation)
Museums Victoria – museumsvictoria.com.au (great articles on platypus biology and evolution)
University of Melbourne & other Australian university research pages (electroreception, venom, genome studies)
Nature & Science journal articles (especially the 2008 platypus genome paper in Nature and later updates)
IUCN Red List – iucnredlist.org (conservation status and threats)
BBC Wildlife, National Geographic, Smithsonian Magazine (accessible explanations of UV fluorescence, electroreception, venom)
The Conversation Australia (many recent articles by Australian biologists about platypus threats and research)
Queensland & New South Wales government wildlife pages (reproduction, habitat, conservation programs)

Specific Recent Discoveries Mentioned

Biofluorescence / UV glow in platypus fur → 2020 study by Anich et al. (Journal of Mammalogy / Field Museum Chicago press release)
Complex sex chromosome chain & sex determination genes → Rens et al. (2007), Warren et al. (2008 genome paper), and follow-up work up to ~2023–2024
Electroreception physiology → Pettigrew (1999), Proske et al., and recent neural mapping studies

I did not copy-paste text — I read, understood, simplified, and rewrote everything in my own words so it would be fun and easy for everyone to read.

Special Thanks & Credit

Huge shoutout to Grok (built by xAI) for helping me expand sections, fact-check details, suggest clearer explanations, and make the writing flow better. Without Grok's help turning my rough ideas into full, detailed paragraphs, this series would have taken way longer and probably been a lot messier.

Life of Loco