Sign in

Dr Craig R McClain

@drcraigmc.bsky.social
11K followers 2.3K following 2K posts

Deep-sea biologist. Two obsessions: the biodiversity of Earth's largest habitat, and why body size varies across all of life. Science communicator, ocean's weirdest animals daily.

PostsRepliesMedia
Dr Craig R McClain @drcraigmc.bsky.social · 29/09/2026
Finally got around to making Raup's mollusk shell model work in R. Also spent too much time trying to give a retro look. #marinelife #molluscmonday
2196
Reposted by Dr Craig R McClain
Blue Collar | White Coat Podcast @bcwcpodcast.bsky.social · 25/09/2026
Some academics are truly "elite" thanks to the real world work experience they cultivate before even applying to a program like Dr. Craig's. Episode 4 is out now! #STEM #STEMjobs
221
Reposted by Dr Craig R McClain
Randall Munroe @xkcd.com · 22/09/2026
Tyrannosaurus xkcd.com/3300/
Comic. [Person with long hair pointing to diagram with Tyrannosaurus Rex standing next to a person.] PERSON: We now believe the primary prey of Tyrannosaurus Rex was these humans who kept standing next to it for scale.
91121062094
Dr Craig R McClain @drcraigmc.bsky.social · 22/09/2026
Expectation versus reality
2161
Dr Craig R McClain @drcraigmc.bsky.social · 17/09/2026
For no particular reason at all, Ed Sheeran is on my mind. Anyway: the gulper eel is almost all mouth, unhinging its jaw to swallow prey larger than itself before deflating to a thin whip. A whole animal built around the shape of you. 🐟 🧪 #marinelife
youtu.be
Watch this eel inflate its head like a balloon
YouTube video by Science Magazine
0327
Dr Craig R McClain @drcraigmc.bsky.social · 17/09/2026
Some glass sponges may be the oldest animals on Earth. Individuals of Monorhaphis chuni are estimated at over 11,000 years old, and they build a single skeletal spike up to 3m long, the largest natural glass structure any animal makes. 🧪 #SpongeThursday #HowToBuildAGiant #marinelife
26821
Dr Craig R McClain @drcraigmc.bsky.social · 17/09/2026
Talking about this paper today in my undergraduate ecology course.
020
Reposted by Dr Craig R McClain
Seth Finnegan @sethf.bsky.social · 13/09/2026
Everyone had their own weird way of coping with the pandemic, and mine was photographing nudibranchs on the California coast. Fun to have been able to parlay that into a PNAS cover, and to have been part of such interesting work led by @isaacpesca.bsky.social & @drcraigmc.bsky.social! #nudibranch
A close-up of an aeolid nudibranch sea slug, Phidiana hiltoni, on a piece of kelp. The slug is translucent white with orange-banded rhinophores and gray cerata with pale orange tips.
49617
Reposted by Dr Craig R McClain
Holly Bik @hollybik.bsky.social · 12/09/2026
Never thought I’d wake up and see @echinoblog.bsky.social @noaa.gov on the front page of the celebrity gossip subreddit. But I guess we have two new #deepsea celebrities! www.reddit.com/r/popculture...
0519
Dr Craig R McClain @drcraigmc.bsky.social · 08/09/2026
When your postdoc @isaacpesca.bsky.social is so awesome they give him the cover of PNAS! Excellent photo by @sethf.bsky.social! And excellent coauthors of @pedromonarrez.bsky.social @tomjwebb.bsky.social among others.
1203
Reposted by Dr Craig R McClain
Dr. Or M. Bialik |📚|🔬|🌊|⚒️ @obialik.bsky.social · 04/09/2026
Climate change affects the physiology of animals in different ways. Many shrink, but some grow, and the change can also depend on where the animal lives. 🧪 Link: doi.org/10.1073/pnas.2606099123​
Change in standardized body size slopes for different invertebrates for low vs high emission scenarios
093
Reposted by Dr Craig R McClain
Proceedings of the National Academy of Sciences @pnas.org · 04/09/2026
As the climate changes, some mollusks will shrink to half their current size, while others will grow up to 15% larger, depending on lineage and location. The ecological and social consequences for marine ecosystems could be profound. In PNAS: ow.ly/iUo450ZJsTl
McDonald's dorid, a California nudibranch representing the molluscan diversity examined in this study.
CREDIT: Seth Finnegan.
0125
Reposted by Dr Craig R McClain
Mongabay @mongabay.com · 03/09/2026
[Commentary] Deep in the Gulf of Mexico, the unique and unstudied Orca Basin is threatened by corporate plans to dump organic waste for carbon storage. In this op-ed, deep-sea biologist @drcraigmc.bsky.social warns that this ancient deep-sea ecosystem is a living system, not a waste repository.
mongabay.cc
Gulf of Mexico’s unique Orca Basin shouldn’t become a carbon dump (commentary)
It’s 3 a.m. and I am standing on the deck of a research vessel, staring into water so dark it looks solid. I feel what I felt standing at the rim of the Grand Canyon, watching the sun set: there are…
13722
Dr Craig R McClain @drcraigmc.bsky.social · 03/09/2026
UL Lafayette-led study finds climate change won’t simply shrink marine life
louisiana.edu
UL Lafayette-led study finds climate change won’t simply shrink marine life
Research led by scientists at the University of Louisiana at Lafayette challenges a long-held assumption about the effects of climate change on marine life: warmer oceans won’t simply make animals
1118
Reposted by Dr Craig R McClain
Jo Wolfe, PhD @jopabinia.bsky.social · 15/05/2024
#InsertAnInvert2024 WHO ARE IN THE FALSE CRABS. The Anomura, on the right side, include: - squat lobsters (contains porcelain crabs) - more squat lobsters (contains Lomis, yeti crabs) - mole crabs - hermit crabs (contains king crabs, coconut crabs) 🦀🦑🧪 onlinelibrary.wiley.com/doi/full/10....
Gross morphology in the convergent evolution of representative true crabs (Brachyura), porcelain crabs (Porcellanidae), hairy
stone crabs (Lomisidae), and king crabs (Lithodoidea). Losses (open circles) observed in frog crabs (Raninoidea). Topology simplified from our previous papers. Body plan features are assumed to be present in the common ancestor of each marked lineage but may vary considerably within each group.
Photo credits: (A, N) Ondřej Radosta; (B, D, H, I) Tin- Yam Chan; (C, E, G, K, M) Arthur Anker; (F) Ling-Kuang Tseng; (J) Michael Marmach; (L) Darryl Felder
212951
Reposted by Dr Craig R McClain
Chris Mah @echinoblog.bsky.social · 03/09/2026
@mbarinews.bsky.social MAGNAPINNA! youtu.be/cEw74DoCv6Q?...
youtu.be
MBARI researchers film chance encounter with a rare deep-sea bigfin squid
YouTube video by MBARI (Monterey Bay Aquarium Research Institute)
02510
Dr Craig R McClain @drcraigmc.bsky.social · 02/09/2026
Your taxonomic post of the day
0479
Dr Craig R McClain @drcraigmc.bsky.social · 01/09/2026
A company got EPA approval to sink 20 tons of sugarcane waste into the Gulf's Orca Basin to "store carbon." Even if they blanketed the entire basin, it would offset less than a week of human emissions, while risking one of the rarest ecosystems on Earth. I wrote for @mongabay on why. 🧪 #marinelife
news.mongabay.com
Gulf of Mexico’s unique Orca Basin shouldn't become a carbon dump (commentary)
It’s 3 a.m. and I am standing on the deck of a research vessel, staring into water so dark it looks solid. I feel what I felt standing at the rim of the Grand Canyon, watching the sun set: there are p...
33022
Reposted by Dr Craig R McClain
tomjwebb @tomjwebb.bsky.social · 01/09/2026
Delighted to see this out now in PNAS - how do we expect marine mollusc body sizes to react to the coming decades of climate change? Check our Craig's thread for details…
083
Dr Craig R McClain @drcraigmc.bsky.social · 31/08/2026
A very on-theme #MolluscMonday: our new PNAS paper projects how 23,000+ mollusc species will change size as the ocean warms. Most shrink, some grow, and which happens comes down to body plan. Clams downsize. Squid may bulk up. 🦑 🧪 #MolluscMonday #HowToBuildAGiant #marinelife
pnas.org
PNAS
Proceedings of the National Academy of Sciences (PNAS), a peer reviewed journal of the National Academy of Sciences (NAS) - an authoritative source of high-impact, original research that broadly spans...
3279
Dr Craig R McClain @drcraigmc.bsky.social · 31/08/2026
New in PNAS today: we projected how climate change will reshape the body size of marine life across the entire ocean. 23,329 mollusc species, every ocean basin. The headline everyone expects is "life shrinks." The real answer is far stranger. 🧪 #marinelife www.pnas.org/doi/10.1073/...
pnas.org
Nonuniform resizing of marine life under climate change | PNAS
Global warming is often predicted to drive universal declines in animal body size, but empirical evidence remains equivocal. This is particularly t...
29647
Dr Craig R McClain @drcraigmc.bsky.social · 29/08/2026
More potential destruction of our national parks
mountainjournal.org
Old rift reopens as Trump administration amends Grand Teton pathway decision - Mountain Journal
Conservation groups decry the federal government’s do-over as both a dubious procedural maneuver and threat to wildlife. But longtime trail advocates are pleased.
071
Dr Craig R McClain @drcraigmc.bsky.social · 28/08/2026
America's national parks are being quietly taken apart: mass layoffs, record budget cuts, monuments shrunk by millions of acres, protected land reopened to drilling. None of this is speculation. Ten sourced examples, one at a time. 🧪
4175121
Dr Craig R McClain @drcraigmc.bsky.social · 28/08/2026
The heaviest living thing on Earth isn't a whale or a tree, it's a fungus in Oregon spread across 2,000+ acres and thousands of years old, most of it underground. We picture giants as tall. Some of the biggest just quietly went wide, out of sight. 🧪 #HowToBuildAGiant #plants
14212
Dr Craig R McClain @drcraigmc.bsky.social · 28/08/2026
Godzilla could never actually stand. Scale a body up and weight climbs faster than bones can bear, so a lizard the size of a building would collapse under itself. The only place to be that big is the ocean, where water carries the weight. Kaiju would all need to be marine. #HowToBuildAGiant #Kaiju
190
Dr Craig R McClain @drcraigmc.bsky.social · 28/08/2026
The largest arthropod ever was a sea scorpion. Jaekelopterus stretched about 2.5 meters, longer than a person is tall, hunting the seas 400 million years ago with claws half a meter long. Nothing with an exoskeleton has come close since. 🦂 🧪 #FossilFriday #HowToBuildAGiant Artwork by Dani Navarro
818845
Reposted by Dr Craig R McClain
Lisa @tuexplorer1.bsky.social · 27/08/2026
Elpidiidae ballast dump before liftoff @nautiluslive.org dive 8.25.25 #MarineLife
0275
Dr Craig R McClain @drcraigmc.bsky.social · 27/08/2026
Kentro-saurus? More like Kentro-glaze-us. Those spikes were once for defense. Now, strictly pastry.
071
Dr Craig R McClain @drcraigmc.bsky.social · 27/08/2026
At 7,200 m in the Java Trench, most scavenging amphipods swarm the bait. But one kind ignored it, clinging to worm tubes and the camera lander for hours and shoving off any neighbor that tried to muscle in. First time this is seen in a hadal scavenger. #marinelife doi.org/10.1093/jcbi...
0130
Dr Craig R McClain @drcraigmc.bsky.social · 27/08/2026
The bigfin squid was first hauled up in 1883 and not formally described until 1998, 115 years later. A new paper compiling every sighting shows it lives across three oceans and down past 6,000 m, yet it's still known only to genus, identified from grainy deep-sea video. 🦑 🧪 #marinelife
link.springer.com
Global distribution and depth of the Bigfin squid Magnapinna spp - Marine Biology
The Bigfin squid Magnapinna spp. is elusive and rarely encountered, yet its charismatic morphology of large fins and extraordinarily long tentacle filaments makes it an instantly recognisable deep-sea...
07822
Dr Craig R McClain @drcraigmc.bsky.social · 27/08/2026
An online exhibit worth your time: artists paired with deep-sea biologists to turn real research into art. Bigfin squid in linocut, carnivorous sponges in wire, vent octopus in watercolor. Run by the Deep-Sea Biology Society, and gloriously full of overlooked invertebrates. 🧪 #SciArt #marinelife
artseamatchmaking.com
ART & SCIENCE - All Artworks
PANDORA'S SUBMERSIBLE Julia & Elyse
1197
Dr Craig R McClain @drcraigmc.bsky.social · 25/08/2026
A giant clam can top 200 kg and live over a century, but it barely feeds. It farms algae in its colorful mantle, living on the sugar they make in sunlight. Its blue-green cells act like lenses, aiming light at the captive gardens inside. Sunlight built this giant. 🧪 #HowToBuildAGiant #marinelife
621658
Reposted by Dr Craig R McClain
Andrew D Thaler @drandrewthaler.bsky.social · 25/08/2026
One of the unexpected delights of writing this book is that, as scientists, we rarely just sit down and talk to each other about how cool the deep sea is and how much fun it is to be at sea riding the edge of human knowledge. It's cool. We're cool. Be cool.
0424
Dr Craig R McClain @drcraigmc.bsky.social · 22/08/2026
The Guardian's Invert of the Year is a solar-powered seaslug the size of a grain of rice. The leaf sheep eats algae, keeps the chloroplasts alive inside its own body, and then runs partly on sunlight. And it is unfairly adorable. 🐑 🧪 #marinelife www.theguardian.com/environment/...
213844
Reposted by Dr Craig R McClain
Eden Robins @edenrobins.bsky.social · 20/08/2026
So incredibly excited for Craig's work: "This project sets out to answer one of the most consequential unresolved questions in ocean science: have we been fundamentally misreading the biodiversity of our own planet?"
0216
Dr Craig R McClain @drcraigmc.bsky.social · 20/08/2026
My university wrote up our new $2M NSF project, and I got to say the thing I believe: the deep sea isn't empty, it's just unread. We're using DNA to read it at a resolution nobody has tried, sampling the abyssal plain to find who really lives there. 🧪 #marinelife louisiana.edu/news/ul-lafa...
louisiana.edu
UL Lafayette biologist receives NSF award to investigate deep-sea biodiversity
How far do deep-sea species range, and how many remain undiscovered?
3707
Dr Craig R McClain @drcraigmc.bsky.social · 18/08/2026
But my big passion project is taking all my time! Can someone create one for me?
130
Dr Craig R McClain @drcraigmc.bsky.social · 18/08/2026
13mya in Colombia, the top predator wasn't a big cat or a bear. Probably Purussaurus, a caiman relative bigger than a bus. Bite marks found on the skulls & bones of massive hoofed mammals. South America was short on large mammal predators, so a crocodile filled the gap. #HowToBuildAGiant
Reconstruction of Purussaurus neivensis attacking Pericotoxodon platignathus. Credit: Miguel Hernandez
1122
Reposted by Dr Craig R McClain
bookswain.bsky.social @bookswain.bsky.social · 03/08/2026
For #MolluscMonday an illustration titled “Ocean Shells” from my 1861, second edition copy of ‘The Sea and Its Living Wonders’ by Dr. Georg Hartwig. 🌊 🦑 #sciart
An illustration of a heap of wheels on a beach from a variety of species.



#oceanlife
0276
Dr Craig R McClain @drcraigmc.bsky.social · 17/08/2026
For #molluscmonday enjoy this video of a Magnapinna (bigfin) squid. That "Elbow" Joint? A sharp, right-angle bend forms where their thick upper arms transition into ultra-thin dangling filaments. We think this bend keeps their long threads from tangling www.youtube.com/watch?v=Z72S...
youtube.com
A Ghostly Find: Bigfin Squid
YouTube video by NOAA Ocean Exploration
0314
Dr Craig R McClain @drcraigmc.bsky.social · 17/08/2026
The female blanket octopus trails meters of iridescent webbing. The male is the size of a walnut, one of the widest size gaps between sexes of any animal. He hangs out in man o' war tentacles sometimes tearing them off and using them as weapons. #MolluscMonday #HowToBuildAGiant #marinelife
15014
Dr Craig R McClain @drcraigmc.bsky.social · 16/08/2026
The 2026 Ocean Photographer of the Year finalists are stunning. Also: of 20 photos, 2 feature invertebrates. Invertebrates are roughly 95% of all animal species in the ocean. Respect to the crab and the snail carrying 34 invert phyla on their backs.🧪 #marinelife www.popsci.com/environment/...
popsci.com
20 magnificent finalists from the 2026 Ocean Photographer of the Year awards
'This year’s finalists have produced work of extraordinary depth and courage.'
0276
Dr Craig R McClain @drcraigmc.bsky.social · 12/08/2026
This may be my new favorite sea cucumber. Look at that frilly beast!
0150
Dr Craig R McClain @drcraigmc.bsky.social · 11/08/2026
There’s a special place in hell reserved for whoever leaves 600 pounds racked on the leg press and walks away. I have to strip it plate by plate just to exist. Indeed, we are not the same “bro”
060
Reposted by Dr Craig R McClain
Meghan Wilson Duff 🦑 @mwduff.bsky.social · 16/04/2026
It's sneaking up. 🦑 bookshop.org/p/books/alex...
Picture book cover. Giant golden squid on one side of the cover looking down at a child. Squid’s arms and tentacles circling the cover. Title Alex & The Squid in the middle. Child is holding a book. Text by Meghan Wilson Duff and Art by Nathalie Dieterlié.
2114
Dr Craig R McClain @drcraigmc.bsky.social · 10/08/2026
Two deep-sea giants, two ways to hold on. The colossal squid grips prey with rotating, swiveling hooks on its arms. The giant squid instead lines its suckers with rings of sharp, saw-like teeth, the ones that scar sperm whales. Same problem, two brutal solutions. 🦑 🧪 #MolluscMonday #HowToBuildAGiant
The suction cups of a giant squid and the hooked ones of a colossal squid.
45822
Dr Craig R McClain @drcraigmc.bsky.social · 07/08/2026
After a day of Megalodon, something calm. The tallest living thing is a redwood, and the heaviest is a fungus in Oregon spread across 2,000+ acres. The biggest organisms on Earth aren't animals at all. #plants #HowToBuildAGiant
0200
Dr Craig R McClain @drcraigmc.bsky.social · 07/08/2026
Spent today explaining why Megalodon is extinct. But here's what art does that my thread can't: make you feel the size. A good scale drawing of Megalodon next to a diver lands harder than any number I can give you. Show me your favorite size-comparison art. 🧪 #SciArt #HowToBuildAGiant
3659
Dr Craig R McClain @drcraigmc.bsky.social · 07/08/2026
1/10 People keep asking if Megalodon is still out there. It isn't, and a clear writeup of how we actually know wasn't really anywhere online. So I wrote one. Here's the short version, then the full piece. 🧪 🦈 #FossilFriday #marinelife
813642
Dr Craig R McClain @drcraigmc.bsky.social · 07/08/2026
New Evidence Suggests Dinosaurs Had Quinceañeras — theonion.com/new-evidence...
theonion.com
New Evidence Suggests Dinosaurs Had Quinceañeras
BOZEMAN, MT—Upending long-held beliefs about how the prehistoric reptiles commemorated a juvenile female’s transition into adulthood, new evidence published Thursday by researchers at Montana State Un...
0191