Colorful Crinoids through Time

There is nothing like flying in the current through the crystal clear waters of Komodo National Park!

What makes this area so attractive?  It POPS with millions of colorful crinoids.  Crinoids are so feathery and delicate, yet their parts are hard enough to have left a robust fossil record.  Today we will explore the fascinating evolutionary history of the crinoids through my underwater photos and fossils.

Modern crinoids,  Papua New Guinea

Modern crinoids,
Komodo, Indonesia

Modern crinoids, Komodo, Indonesia

Modern crinoids at night,
Komodo, Indonesia

First, lets briefly consider the structure of crinoids

 The very first crinoids, as well as some deep water species found today, were attached to the ocean bottom by a stalk made of up columnals.  The stalk connected to a cup (or calyx), which then gave rise to five arms.

Fossil crinoids first appeared in the mid Paleozoic Era

approximately 490 million years ago (recall that the three eras are Paleozoic, Mesozoic and Cenozoic/recent).  They quickly diversified; over 5000 different species proliferated and coated the the sea floor.   They nearly became extinct during the catastrophic mass extinctions at the end of the Paleozoic Era, but rebounded and diversified again in the early Mesozoic Era.

Check out these early crinoids

Note that they have very  few stiff and unbranched arms, and that they have a stalk.


Five arms (Onychocrinus) Mississippian, Indiana

Five arms (Onychocrinus)
Mississippian, Indiana

Crinoid stems and individual segments (columnals) (multiple species)

Crinoid stems and individual segments (columnals)
(multiple species)

Jimbacrinus Permian, Australia

Permian, Australia

Cupressocrinus Devonian, Morocco

Devonian, Morocco




















Increased predation by sea urchins  during the Mesozoic Era led to new adaptations

The sea urchins  developed sharp vicious teeth which allowed them to penetrate the defensive armor of the early crinoids.  Only the crinoids that could adapt survived.  Multiple structural and behavioral changes occurred:

1.  Motility:  The early crinoids were anchored to the ocean bottom by a stalk and could not escape predation.  Later crinoids lost the stalk and acquired the ability  to walk or swim.  (watch a video here).

2.  “Pseudoplanktonic adaptations”:  Some crinoids such as Scyphocrinites had air filled bladders which allowed them to float in the water column, away from the sea urchins on the ocean bottom.  Still others (Pentacrinites) attached to the bottoms of floating logs and drifted with the logs.

Crinoid float (Scyphocrinites) Devonian, Oklahoma

Crinoid float (Scyphocrinites)
Devonian, Oklahoma

Crinoid float (Scyphocrinites) Devonian, Oklahoma

Crinoid float (Scyphocrinites)
Devonian, Oklahoma

3.  Flexible and increasingly branched arms: Early crinoids, such as Onychocrinus and Jimbacrinus, had only 5 stiff arms.  Later crinoids, such as Pentacrinites had ten or more highly branched arms. The flexibility and branching allowed the crinoids to avoid some predation.  It also allowed them to filter more water and trap more food.


Pentacrinites Jurassic, England

Jurassic, England

Traumatocrinus Triassic, China

Triassic, China

4.  Autotomy: (self amputation).  Much like their relatives the starfish, crinoids developed the ability to discard branches or arms when a predator attacked.  This would either satisfy or distract the predator while the crinoid escaped.  Lost arms could be regenerated.

5.  Nocturnal behavior:  Some species became nocturnal, hiding in cracks on the reef during the daytime to avoid predation.

modern crinoid Komodo, Indonesia

modern crinoid
Komodo, Indonesia

What are crinoids like today?

Today there are 500 species of crinoids, divided into two major groupings.  The comatulid crinoids are stemless and motile, and they are prevalent in many different ocean environments.  These are the crinoids we see while diving.  Only a few species of stalked crinoids remain, living  only in deep water (>300 feet), where the darkness provides cover from predatory fishes.


Find out more

Click for more general info on crinoid fossils and modern crinoids.  To find out more about adaptations of crinoids in the Mesozoic era, click here.

Crinoid Pendant (Platycrinites) by Scuba Jill

Crinoid Pendant (Platycrinites)
by Scuba Jill

Sweetie! (in a crinoid costume)

(in a crinoid costume)




Doing Drugs with the Sponges!

Over 5800 bioactive molecules have been isolated from sponges! 

Today we will see why scientists are using sponges to find new treatments for cancer.  We will also see some beautiful psychedelic images of sponges inspired by this topic and by my underwater photo of a sponge from Papua New Guinea.

Sponges are very simple

They lack organs (even ascidians have organs!). Their bodies are full of holes that allow water to move through them, and they extract nutrients from the water and eliminate waste into the water.  That’s it.  So what gives these humble organisms the awesome power to produce chemicals that can destroy human cancer?


CLICK to make me bigger!

Sponges are uniquely positioned to produce useful molecules

1.  Their porous structure provides a home for numerous symbiotic bacteria and other microflora; approximately 50% of the dry weight of a sponge is associated microbes.  These microbes contribute additional bioactive molecules.  We would not be able to find these microbes without sponges.

2.  Sponges live in a very competitive environment.  The coral reef is lush, very desirable and limited.  Thus, competition for space is intense and sponges must produce molecules that defend their space against other organisms that want to live on the reef.

3.  Because they are very simple and live their lives attached to a substrate, sponges must secrete toxic compounds to defend themselves against predators. Compounds that are toxic to sponge predators may also show toxicity against cancer cells.

4.  Sponge/microbial toxins have to be super potent because they are immediately diluted by surrounding sea water.  This is important because chemotherapy is used at the lowest dose possible to minimize damage to normal cells.


CLICK to see me in focus (it’s cool)

Two sponge-derived compounds are used to treat cancer!

1.  Ara-C (Cytarabinine), from the sponge Cryptotethya crytpa, is one of the most effective chemotherapies against acute leukemia.  Ara-C is similar but not identical to the nucleotide cytosine (cytosine, along with the other nucleotides adenine, thymine, guanine, ie, CATG, are the building blocks of DNA).  It is incorporated into human DNA during DNA doubling (replication) in dividing cells, however, it is different enough from human cytosine to cause DNA replication to fail.  Since cancer cells are rapidly growing and dividing, they are preferentially affected by drugs which inhibit DNA replication.

2.  Halichondrin-B (Halaven), from the sponge Halichondria okadai, is used to treat patients with metastatic breast cancer that is resistant to other drugs.  This drug has a novel mechanism of action, which allows it to be effective when other drugs have failed.  Halaven interferes with microtubules, the molecules that help move chromosomes during cell division.  Again, cancer cells are rapidly growing and dividing, and are preferentially affected by drugs which inhibit cell division.

Original photo (Tufi, PNG)

sponge, original photo

How are sponge-derived drugs prepared?

I know you might be worried that this is going to lead to tons of sponges being plucked from coral reefs and turned into drugs.  This is simply not the case.  Drugs for patient use are prepared by one of the following methods:

1.  Sponges can be farmed in the ocean or in tanks.

2.  Drug-producing microbial symbionts can be cultured in the lab.

3.  Genes encoding the drug can be cloned into bacteria that can then be mass produced.

4.  Drugs can be chemically synthesized.

Find out more here

THE SIMPLE SPONGE SAVES HUMAN LIVES! Link to a great article about drug development from marine invertebrates, and to an interesting book about sea life and drug discovery.

"Is there catnip in these sponges?"

“Is there catnip in these sponges?”

A “Locavore” Rock Shop: Part 4 of the Northern California Coast Series

Tons of rocks greet the visitor to Chapman's Rock Shop in Humboldt County

Tons of rocks greet the visitor to Chapman’s Rock Shop

Boxes and boxes of REAL fossils are inside!

Boxes and boxes of REAL fossils are inside!

Data and I stop at every roadside rock shop hoping for the rock shop of old – – a sprawling crusty shop owned by an obsessive collector with a bounty of self-collected local treasures at good prices.  I call these “locavore” rock shops, because they feature specimens from the surrounding area, chipped painstakingly out of the rocks by actual fossil fanatics.

Fossils are often FAKE!

These days rock shops all sell the same old crap- amethyst crystals, fake fossils from Morocco and China, and grotesque “art” made from gluing these things together.  The fakery is so pervasive that there are entire websites dedicated to the topic (fake fossils).  These are not even substandard specimens that have been repaired.  They are all out fabrications made from plaster in Moroccan fossil factories!  And some sell for thousands of dollars!


We found a shop where you can buy real stuff!

What a treat it was to discover Chapman’s Gem and Mineral Shop in Humboldt County on our NorCal road trip!  Sure they had the requisite mass produced fossils and amethyst crystals, but they also had the key elements of a “locavore” rock shop.  The shop was established in 1959 by the Chapmans, features specimens from California and the northwest US contributed from local collectors, even has a museum section featuring their prize specimens, and has about an acre of rough material in bins outside the shop.  If you are avid collector, you will see specimens in the museum that haven’t been available in years.

Real fossil echinoids from California

Real fossil echinoids from California

Real fossil sand dollars from California

Real fossil sand dollars from California

Fossil marine invertebrates!!!!

How wonderful to see real, authentic fossil marine invertebrates with all of their scratches, missing bits and blemishes. Echinoids (fossil sea urchins and sand dollars) from all over California were our favorite discovery.

Polished fossil oyster pieces, California

Polished fossil oyster pieces, California

Another exciting discovery was a bin of fossilized oyster fragments (pectens) that had been cut and polished into shapes suitable for jewelry.  The repeating pattern formed by the fluting of the shell is very geometric when polished.  Replacement of the oysters by different minerals during fossilization caused the color variations.  According to the store clerk, these specimens were collected near Crescent City in Northern California and were approximately 1-15 million years old.  They were only $1.00 each! I can’t wait to start using them in my jewelry making!

I highly recommend a visit to this store if you happen to be in the area and love marine fossils!  And remember: if a fossil looks too good to be real, then it probably isn’t!



Sweetie can sniff out the fake fossils every time!

Sweetie can sniff out the fake fossils every time!

NO DISCLAIMERS!  The above is my own opinion and has been influenced only by the fossils!

The Glass Beach: Part 3 of the Northern California Coast Series

Were there tide pools at the Glass Beach?

Were there tide pools at the Glass Beach?

Mulltiple colors of glowing glass are dense throughout the beach

Mulltiple colors of glowing glass








Imagine landing on another world with treasure everywhere, there for the plucking!  The Glass Beach is every collector’s fantasy!

I’d heard lusty stories of the Glass Beach from Kirabranchus, so off we went to Fort Bragg, CA.  Just a short walk from a parking lot, over a small bluff and POW we were one with the rocky coast, the surf, and a beach bursting with color!  Fragments of smooth, glazed glass 8 inches deep!


Multiple colors of sea glass including rare cobalt blue

Multiple colors of sea glass including rare cobalt blue

Some pieces still retain the bottle structure

Some pieces still retain the bottle structure

Multiple hues of green, yellow, brown, and clear, mostly from old beer and soda bottles, and scattered milky white fragments of dinnerware crackled beneath our boots.  A rare coveted blue fragment had us screaming with pleasure! The pieces varied in shape from irregular to triangular to perfectly rounded droplets of frosted color.  Some  of the pieces even bore markings and grooves, which can allow collectors to determine the bottle of origin.

Seafoam green

Seafoam green

Lime green

Lime green

At least six different shades of green were found

At least six different shades of green were found








Each of the greens has its own unique history.  Seafoam green, not an unusual finding on this beach, is from Coke bottles, usually pre-1970s.  It varies in hue because the glass composition differed slightly at different bottle factories.  Lime green dates back to the mid-to late 1900s, and is a “depression glass” because it was used for tableware during the depression. Citron was often used to bottle wine.  Forest green was used for antique spirits bottles and snuff bottles.

How did these beautiful tidbits get here?  I call it “the Sea Glass Cycle.” In the beginning, manufacturers produced glass by combining sand (silica, SiO2) with soda (Na2O) and lime (CaO), and formed it into bottles, dinnerware, etc.  This glass was used by local residents, then dumped onto the coast from 1906-1967.

Over the years, two processes combined to break the glass down and give it the characteristic frosted surface.  First, the glass was physically pounded by the ocean, with constant wave action smoothing and grinding the surfaces.

Some very weathered, frosted pieces

Some very weathered, frosted pieces

Second, a chemical process known as weathering or corrosion contributed heavily to the frosted appearance.  Glass is composed of a framework of repeating units of silicon dioxide (SiO2), with smaller percentages of soda (Na2O) and lime (CaO).  Na and Ca are large atoms that become replaced by smaller H+ ions from sea water (they “leach out”).  This destabilizes the silicon dioxide framework.  The weakened glass cracks and pits; these changes produce the frosted surface (weathering crust).  Eventually the silicon dioxide network is destroyed, and the glass breaks down into particles of sand, completing the cycle.

Ironically, the glass that was once garbage is now highly prized by collectors and jewelers!  The value will only increase as the current sea glass degrades or is collected.  Also, with the shift from glass to plastic bottles, and the cessation of garbage dumping into the ocean (at least in the US), less sea glass will be created.

Sea glass makes beautiful jewelry (sea glass on cholla coated with fine silver; created by Scuba Jill)

Sea glass jewelry by Scuba Jill

When is the best time to collect sea glass? Low tide, especially after a storm, is the best time to look for sea glass.  The Glass Beach and surrounding beaches are good all the time.

How do I get to the Glass Beach?  The Glass Beach is in MacKerricher State Park, Fort Bragg, CA, and collecting is NOT allowed.  However, on another beach just south of the Glass Beach there is plentiful sea glass, the specimens are larger, and collecting IS allowed.



Sweetie finds sea glass relaxing.

Sweetie finds sea glass relaxing.

Stay tuned for Part 4 of this series when Scuba and Data visit a rock shop in Humboldt County!

Anemones Rock! : Part 2 of the Northern California Coast Series

Anemones rock!  They are so delicate, colorful, AND abundant in tide pools. The tide pool species are much smaller than the species we typically see on coral reefs, but there are lots of them here and they are gorgeous!  And they have two vastly different appearances: tentacles open and tentacles closed.

Aggregating anemones (Anthopleura elegantissima)

Aggregating anemones
(Anthopleura elegantissima)

Retracted aggregating anemones (Anthopleura elegantissima)

Retracted aggregating anemones
(Anthopleura elegantissima)

We saw in Part 1 of this series that thousands of tiny retracted aggregating anemones are a good clue that there will be open anemones as you get closer to the water.  The closed anemones have withdrawn their tentacles to conserve water.  As a result, they look like little balls of mud speckled with shells and debris, with a punctate central opening.  They retract not only to protect themselves but to preserve their water when the tide goes out.   This gives individuals a very rich, moist and succulent look.

I love seeing vast sheets of retracted aggregating anemones, spreading out across a wall or horizontal rocky surface.  The repeating pattern of identical units reminds me of many natural patterns, especially the structure of many human tissues. The anemones are genetically identical clones, and form monomorphous layers — an impressive profusion of life, especially given the harsh conditions in which they live.

Anemone splitting in two

Anemone splitting in two

The clones are formed when an individual divides in half (binary fission).  Repeated fission results in large aggregates of clones.   When genetically different anemones get close to the clones, the anemones on the edge of the cluster use a specialized tentacle called an acrorhagi to attack them and defend their territory.  You can watch a video of anemones fighting here.


Large solitary anemones, such as the giant green anemone  retract into really other worldly structures.  Can you believe that life forms with this morphology live with us on this planet? When these are retracted, they hang down off rocks like amorphous blobs and form funky pendulous shapes.

Giant green anenome

Giant green anemone

Giant green anemones

Giant green anemones









Giant green anemone

Giant green anemone

Giant green anemone

Giant green anemone








What and how do anemones eat?   Like many sea creatures, anemones contain symbiotic algae which produce food for the anemone via photosynthesis and give them their green color.  Anemones that live under docks and in other non sun-exposed areas lack the algal symbiont and are clear or pale yellow in color.  Anemones are also carnivorous! They use specialized stinging cells on their tentacles (nematocysts) to capture and ingest much more complex animals such as crabs, fish and starfish.  Once the anemone is done eating it’s prey, it ejects the undigestable bits by extruding it’s stomach through it’s mouth, an amazing sight!

Anemone ingesting a crab

Anemone ingesting a crab

Anemone stomach extruded through mouth after a meal!

Anemone stomach extruded through mouth after a meal!








Don’t forget to join me for Part 3 of the Northern California Coast Series:  The Glass Beach!!



How to Find Tide Pools: Part 1 of the Northern California Coast Series

Tide pools are in the partially submerged black rocks.

Tide pools are in the partially submerged black rocks.

What do you do when you just HAVE to see your underwater friends but can’t go diving?  VISIT TIDE POOLS!!  Scuba Jill and Data Diver have been doing this for years to get their underwater critter fix!

Tide pools occur when the ocean recedes during low tide and water is trapped in rocky crevices.  Tide pool organisms must be able to tolerate harsh conditions. The water level varies, pools can dry during low tides or heat up on hot days, waves constantly knock things around, and birds are always prowling for a tasty snack. Why does anything live here??  The rocks are great real estate for anchoring creatures, and then other  creatures prey on them!

So how do we find these magical places?

1. Look for a rocky coastline.  Rocky coastlines can be found throughout California, Oregon and Washington.   In “The Beachcomber’s Guide to Seashore Life of California”, the best beachcombing sites for Northern California include Tomales Bay State Park, Point Reyes National Seashore, Salt Point State Park, Mackerricher State Park, and Mendocino Headlands State Park.  This is a fantastic guidebook, by the way.


Exposed tide pools

Exposed tide pools

2. Check the NOAA tide prediction tables for the area you will be visiting.  The best time to see tide pools is during a low tide, when the ocean has receded farthest from the shore.  Low tide occurs twice a day, and viewing is best for an hour or two before and after. The low tide should be rated as 0 or less on the tide table. Extremely low tides, measured in very negative numbers, occur for a few days after a new moon.  These tides expose areas that are nearly always submerged, and many weird and interesting creatures can be found.  During a -1.9 foot low tide at Pt. Reyes National Seashore, we were able to walk for several hundred feet out onto the kelp forest and spot many delicate sea slugs (the nudibranch Hermissenda crassicornis).

3. Bring the appropriate gear.  You will need sturdy boots and a hiking stick, as footing is  treacherous with waves splashing about, and kelp covered surfaces are slippery.  A guidebook and magnifying glass are useful to identify critters.  Don’t forget sunscreen and a hat!


Numerous closed (retracted) anenomes covered with shell fragments

Numerous closed (retracted) anenomes covered with shell fragments

4.  Look for signs of life.  Barnacles, mussels, limpets and snails start to appear on rocks as you get near a productive area.  These organisms inhabit the high intertidal zone and are adapted for dryer conditions.  As you get closer to the water, you enter the wetter low intertidal zone, with the rocky surfaces coated with thousands of tiny closed anenomes.  They are hard to find at first, because they look like lumps of mud coated by shell fragments, but once you see them, you see them!  Look along rocky walls for starfish and chitons.  Look within pools for open anenomes, crabs, shellfish and other creatures.


5. Be aware of your surroundings.  Watch where you step—there tons of camouflaged critters on the ground.  There are also rogue waves, monster waves that appear without warning.

Don't get caught by the rising tide!

Don’t get caught by the rising tide!

Finally, don’t forget that the tide IS going to come back in—don’t get get trapped out on the rocks like I have!  It’s an icy cold wade back to shore!

In part two of this series, we hang out with my favorite tide pool organisms: the anenomes.

Coming Tuesday!!! Scuba Jill and Data Diver explore the Northern California Coast!

In this four part series, Scuba Jill and Data Diver will explore:

  • How to find tidepools and tidepool creatures
  • Cool marine invertebrates in the intertidal zone
  • The Glass Beach near Fort Bragg in Mendocino County
  • A “locavore” rock shop in Humboldt County

See you right here on Tuesday for more fun stuff!

norcal beach scene 2








Cosmic Corallimorphians!

Amplexidiscus fenestrafer, Tufi PNG wharf, night dive

Amplexidiscus fenestrafer, Tufi PNG wharf, night dive

I love corallimorphians!  They are like coral polyps on steroids.  While most individual hard coral polyps measure around 0.5 inches in diameter, an individual corallimorphian such as Amplexidiscus fenestrafer (shown here), can measure up to 16 inches when fully open!  A huge, solitary invertebrate is always a delicious discovery!

Why is A. fenestrafer sometimes closed and balloon shaped, and at other times open and pancake shaped ?  I wondered that when I came across this big, succulent specimen during a night dive.  Well,  when unsuspecting worms, crabs, starfish and fish happen upon its central oral region, they become trapped and eaten.  As this is happening,   A. fenestrafer closes up into it’s balloon shape, further encasing the prey.   To see  A. fenestrafer in action in an aquarium, click here.  Apparently they are quite dangerous to have in aquariums, because they eat all of the other organisms!

abstract corallimorphIn the abstract image, I have zoomed in on the opening formed when A. fenestrafer is in its balloon configuration.  As you can see, the inside is lined by short cylindrical tentacles.  These tentacles help to push the prey towards the oral region.  The tentacles also contain photosynthetic algae, which provide a supplementary food source for the creature when other tasty treats are unavailable.  My abstract image reminds me of an exploding nebula, blasting molten metal out into space!

So what are corallimorphians?  Are they anenomes?  Or are they hard corals without a skeleton?  Corallimorphians share many structural features with hard corals, and also have stinging cells called nematocysts, another feature of hard corals.  However, because they lack a skeleton, some scientists believe they are more closely related to anenomes.

Genetic studies have led most scientists to believe that corallimorphians are descendants of hard corals that lost their skeletons, or that they are hard corals that only form skeletons in certain sea water conditions.  Several studies support the idea that hard corals can live without skeletons.  In the lab, stressed out hard coral polyps have been observed to detach themselves from their skeletons, swim freely, survive, and subsequently form a new skeleton.   Hard coral skeletons have also been noted to dissolve in low pH conditions in the lab, and the coral polyps continued to survive without them.

Clearly this is one of life’s major mysteries and should give you something to think about next time you swim past a juicy corallimorphian!

Sweetie imitating Amplexidiscus in balloon configuration

Sweetie imitating Amplexidiscus in balloon configuration

Outer Space Ascidians, Part 2: Complex coolness!

IMG_0514_lowqualYou might be wondering, why is she so obsessed with ascidians?  What is so interesting that she needs to do two blog posts in a row about these green blobs?  Does Scuba Jill need to get a life?  Well it turns out that there are some very cool things about the ascidians, and you can really impress your fellow divers with these factoids.

But before we get into that, the guy/gal in the photo is Didemnum molle, ready to greet the away team when it lands on his/her planet (they’re hermaphroditic)!  This individual proudly displayed his/her large, subdivided opening or aperture for me in Komodo, Indonesia.

Ascidians are more complex than they appear.  They have distinct organs including esophagus, stomach, intestine and heart with blood vessels.

Ascidians are in the phylum chordata, just like humans and other vertebrates (animals with backbones). Organisms in this phylum are defined by a developmental stage in which they form a long, flexible midline rod called a notochord.  The notochord provides a backbone-like support for the larva so it can coordinate swimming motion.  In most vertebrates, the notochord does eventually develop into part of the spine (the intervertebral discs), whereas in ascidians it dissolves.  The notochord also provides chemical signals to surrounding cells, causing them to undergo differentiation into the various tissue types.  Isn’t it amazing that organisms as different as humans and ascidians can go through such a similar step in development?  Ascidians are truly an evolutionary link between the vertebrates and invertebrates.  So next time you fin past one of these unassuming little sacs, take a closer look at your brother/sister.