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dantheclamman.scicomm.xyz.ap.brid.gy
Dr. Dan Killam
@dantheclamman.scicomm.xyz.ap.brid.gy
19 followers 1 following 170 posts
Environmental scientist and eclamgelist

Provider of #ClamFacts

[bridged from https://scicomm.xyz/@dantheclamman on the fediverse by https://fed.brid.gy/ ]
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dantheclamman.scicomm.xyz.ap.brid.gy
On Wednesday @ 12 Pacific time I'll be joining my fave mag Bay Nature for a talk about salinity in SF Bay! 🧂🌊 Register at this link: free for members or $5 for nonmembers ! https://baynature.app.neoncrm.com/nx/portal/neonevents/events?path=%2Fportal%2Fevents%2F27375
Painting of SF Bay and event info for my talk: Join Bay Nature and environmental scientist Dan Killam for a talk on the seasonality of salt in our San Francisco Bay waters and how animals have adjusted their lifestyles to survive in response. As Susan Kuramoto Moffat writes, "nearly a quarter of the Bay sloshes in and out of the Golden Gate twice each day with the tide, mixing salt and fresh water on a staggering scale." Within the Bay, these levels of salinity vary greatly over the year (and even over the course of a single day) with early autumn being the saltiest time of year. This fluctuation poses a challenge for the animals living in the Bay, so tune in to learn how mollusks and others make do. This talk is free for Bay Nature Members and $5 for Nonmembers.
November 10, 2025 at 10:00 PM
dantheclamman.scicomm.xyz.ap.brid.gy
[Spot the made up conchological jargon in this list: umbo, tooth, auricle, resilifer, ligament, beak, chondrophore, commissure, lunule, escutcheon, pallial sinus. #clamFacts]

Psych, they're all real, lol. See a glossary here and impress your friends! […]
Original post on scicomm.xyz
scicomm.xyz
November 6, 2025 at 5:52 PM
dantheclamman.scicomm.xyz.ap.brid.gy
New research finds that despite lacking a centralized brain, sea urchins show a surprising degree of nervous system organization, with a diversity of cell types, each with a different specialization, and a complex system of light-detecting cells as well. I often assert to people that as we've […]
Original post on scicomm.xyz
scicomm.xyz
November 5, 2025 at 11:31 PM
Reposted by Dr. Dan Killam
soaproot.sfba.social.ap.brid.gy
@dantheclamman Even in historic times oyster reefs in places like the Chesapeake Bay were much larger than currently. There are some efforts to bring them back underway but on a pretty small scale to date. In researching this post I learned that Maryland once had an Oyster Navy (per […]
Original post on sfba.social
sfba.social
October 30, 2025 at 6:55 PM
dantheclamman.scicomm.xyz.ap.brid.gy
A reef is a sedimentary structure supported by the skeletons of living organisms. Corals are the most famous reef builders, but oysters build them too! Cretaceous rudists, Jurassic lithiotids and bivalves from other time intervals of the past actually rivaled […]

[Original post on scicomm.xyz]
Figure from Kiessling 2009 showing the number of reefs through time. Corals are dominant but often decline following extinctions, and there are points like Cretaceous, early Jurassic and early Triassic when bivalves made up a significant proportion of reefs
October 30, 2025 at 3:27 PM
dantheclamman.scicomm.xyz.ap.brid.gy
Bivalve shells are often colored, either by optically active pigments in the crystal structure of the shell itself, or by the protein layer on top (periostracum) being colored. Yellow and brown are most common, with green and blue being most unusual. As with […]

[Original post on scicomm.xyz]
Beautiful figure from Grant and Williams 2018 showing a spectrum of different shell colors of different bivalves, basically covering all of ROYGBIV. Interiors and exteriors of shells can be colored. Some are only pigmented where the adductor mussel attaches to the interior
October 28, 2025 at 1:50 AM
dantheclamman.scicomm.xyz.ap.brid.gy
Concurring with The Onion: There Absolutely Nothing We Can Learn from Clams

I wrote an article concurring with the recent Onion article: "Biologists Announce There Absolutely Nothing We Can Learn From Clams" […]
Original post on scicomm.xyz
scicomm.xyz
October 23, 2025 at 7:57 PM
dantheclamman.scicomm.xyz.ap.brid.gy
Lewis Carroll's The Walrus and the Carpenter accurately portays how much walruses love to eat bivalves. But walruses mostly hunt in deeper waters than where oysters live, pulling their tongue into their mouth like a piston to suck clams out of the shell. One […]

[Original post on scicomm.xyz]
A blunt gaper clam, showing its pale white aragonitic shell, covered with patchy periostracum with a bald spot at the jumbo. A large obscene looking brown siphon emerges from the left of the shell Illustration from Lewis Carroll's Walrus and the Carpenter showing a walrus talking to oysters on the beach
October 20, 2025 at 8:19 PM
dantheclamman.scicomm.xyz.ap.brid.gy
Unlike their gastropod and cephalopod relatives, there are no known pelagic bivalves that remain in the water column throughout their lives! Many bivalves start as planktonic when they are veligers (larvae), but they all eventually settle down. There are fossil […]

[Original post on scicomm.xyz]
Fig. from Gofas 2000 showing P. henseni from Louisiana. The adult is barely 2 mm long, semi-transparent and nondescript. Growth lines are visible on the shell surface, and a prodissoconch (the larval shell) at the umbo Map from Allen and Scheltema 1972 showing observations of Planktomya larvae. Dark dots basically cover the entire N. Atlantic from Africa to Brazil to Gulf of Mexico to Canada!
October 14, 2025 at 8:34 PM
dantheclamman.scicomm.xyz.ap.brid.gy
It is common for aquaculture to triploid oysters as their stock! They have three sets of chromosomes, rather than the usual two, rendering them sterile. This means their body growth is faster, because they don't put energy into reproduction! A triploid oyster is […]

[Original post on scicomm.xyz]
From Wikipedia, a comparison of representative diploid and triploid oysters. The triploid is twice the body length, with probably three times the soft tissue in terms of area
October 6, 2025 at 7:38 PM
dantheclamman.scicomm.xyz.ap.brid.gy
In October 2024: golden mussels were first detected at the Port of Stockton. They likely came in the ballast water of a ship, coming from one of the places they've previously invaded. In the year since detection they have rode the CA aqueduct all the way down to […]

[Original post on scicomm.xyz]
October 4, 2025 at 8:43 PM
dantheclamman.scicomm.xyz.ap.brid.gy
Can bivalves be domesticated? It turns out that yes, farmed oysters have systematic differences in their genomes compared to their wild counterparts! Farmed oyster larvae have been found to be less hardy in the face of starvation (we've selected for rapid growth instead of flexibility in their […]
Original post on scicomm.xyz
scicomm.xyz
September 29, 2025 at 6:50 PM
Reposted by Dr. Dan Killam
joncounts.mastodon.nz.ap.brid.gy
NEWS FLASH: We have CLAMS living on campus!

As part of last week's Sustainability Weed at #LincolnUniversityNZ, our freshwater ecology tutor Elysia Harcombe did some kick sampling along a farm ditch. Yes, she found clams!

It's the first record on #inaturalist of clams on campus, or anywhere in […]
Original post on mastodon.nz
mastodon.nz
September 29, 2025 at 4:21 AM
dantheclamman.scicomm.xyz.ap.brid.gy
Zachsia zenkewitschi is an extremely cool and strange shipworm that bores into the rhizomes of seagrass on the coasts of Japan and Russia. The females are ~1 cm long and do the burrowing. The males stay larval sized and the female keeps a "harem" of them tucked […]

[Original post on scicomm.xyz]
Diagram from Shipway et al. 2016 showing a Zachsia tucked into a seagrass rhizome like a corndog. She has two siphons poking out the end of the rhizome. Behind those is a kind of cuff or pouch where males spend their lives. The progression of larval to adult males is shown, with the adult looking barely any different from the larvae. Further back is a brood pouch where the mother clam broods her fertilized eggs
September 26, 2025 at 11:19 PM
Reposted by Dr. Dan Killam
soaproot.sfba.social.ap.brid.gy
@dantheclamman Whodunnit? It was the mussel, on the dinner plate, with the dinoflagellate.
September 25, 2025 at 2:14 PM
dantheclamman.scicomm.xyz.ap.brid.gy
In July 1927, over 100 people in San Francisco were sickened from eating mussels. Six died. All experienced loss of feeling and tingling starting as little as a few minutes after their meal, which progressed in some patients into paralysis. There was mass terror […]

[Original post on scicomm.xyz]
A microscope image of Alexandrium catenella. It looks like two brownish hamburgers stuck together
September 25, 2025 at 6:16 AM
dantheclamman.scicomm.xyz.ap.brid.gy
I refer to clams as a cross between a cow and a vacuum cleaner. And like a cow, some species of clams fart out a fair bit of methane, due to methanogenic microbes in their guts! Their farts may account for ~10% of methane released in some environments. So to answer a question I'm sure many of […]
Original post on scicomm.xyz
scicomm.xyz
September 20, 2025 at 10:53 PM
dantheclamman.scicomm.xyz.ap.brid.gy
If a clam claps its valves in the sea and no one is around, does it make a sound? Actually, yes. Researchers were able to use a sensitive mic to pick up the sound of scallops "coughing" as they close their valves, expelling water. It could have use as a […]

[Original post on scicomm.xyz]
A schematic from Di Iorio et al 2012 showing a microphone suspended in a tank of scallops, as well as a top down view of the locations of the scallops Figure from the paper showing the waveform of the cough from the scallop, and also a couple spectrograms
September 18, 2025 at 3:21 AM
dantheclamman.scicomm.xyz.ap.brid.gy
Clam gardens have been used by Pacific Northwest native tribes for thousands of years. They build rock walls to trap sediment, at the right height to be immersed at high tide but also exposed for harvest at low tide. This encourages burrowing clams to settle in […]

[Original post on scicomm.xyz]
Overhead picture from the Northwest Indian Fisheries Commission of a clam garden being built. It is a low rock wall below the tide line. An assembly line of workers carry rocks to the right elevation Diagram from Lepofsky et al. 2021 showing a cross-section of a typical clam garden. The edge of the wall ends exactly at the low tide line, trapping sediment behind it which is exposed at those intervals. It builds the beach surface to a shallower slope, with the shallowest dirt behind the wall the habitat of littleneck clams, while butter clams live deeper.
September 12, 2025 at 8:29 PM
dantheclamman.scicomm.xyz.ap.brid.gy
Class Bivalvia was named by Linnaeus in 1758! During the 19th-20th centuries, it was in vogue to call them Pelecypoda ("axe-feet"), in line with the broader, somewhat bizarre foot obsession of biology. It was seen as better acknowledging other inverts that also have hinged two-valved shells […]
Original post on scicomm.xyz
scicomm.xyz
September 9, 2025 at 6:12 PM
Reposted by Dr. Dan Killam
kumarvibe.mastodon.social.ap.brid.gy
@dantheclamman oh my god 😍🪩💫🪐✨ https://youtu.be/GRzeNlqnRxU?si=MkPmSsGg_iW8xdvz
September 8, 2025 at 10:56 PM
Reposted by Dr. Dan Killam
llewelly.sauropods.win.ap.brid.gy
@dantheclamman @soaproot
crap. The link to the Lyme Regis Museum's website about Buckland's Dinosaur Poo Table no longer works. (The link isn't in the PLOS article you linked to; it's in the smithsonianmag article the PLOS article links to.)
September 6, 2025 at 3:33 PM
Reposted by Dr. Dan Killam
soaproot.sfba.social.ap.brid.gy
@dantheclamman OK, since we're on fossils, is there any known fossilized #pseudofeces ?
September 6, 2025 at 3:46 AM
dantheclamman.scicomm.xyz.ap.brid.gy
Nacre (mother of pearl) isn't very stable chemically, so fossils with nacre are less common, because they dissolve during the millions of years exposed to heat, pressure and fluids in the earth's crust. But in the right conditions, we can find pearl fossils […]

[Original post on scicomm.xyz]
view of a large fossil pearl from Pseudostrea congesta, which was attached to the shell of the large clam. it is made of dully transparent brown calcite and is around 4-5 cm across. on the base of the pearl, growth lines can be seen radiating from the center view of a smaller pearl 5 mm across, cut in half to expose the fine growth lines. these are cleanly circular, but with some signs of larger crystals (called "spar"), a classic marker of recrystallization of the original material
September 5, 2025 at 8:14 PM
Reposted by Dr. Dan Killam
virginicus.universeodon.com.ap.brid.gy
#pseudofeces could be a useful metaphor for more than one feature of modern life. @dantheclamman
September 3, 2025 at 10:09 PM