Being Natural: Tina Petway

When Tina Petway, Associate Curator of Malacology, retired as a schoolteacher in 1999, she finally embarked on fulfilling her dream since she was 12 years old.

Growing up, Petway was frustrated by the lack of resources for young women interested in scientific careers.

“I was walking on the beach, and I ran into this lady who was picking up shells,” Petway said. “She invited me to come back to her house and her office. She gave me shells, Texas-collected shells. Absolutely brilliant lady.”

This lady was none other than Mildred Tate, a renowned malacologist who helped found the Brazosport Center for the Arts and Sciences in Clute, Texas. Tate gave Petway rare specimens, many books, and a strong foundation for future adventures.


Associate Curator of Malacology Tina Petway pursued shell science later in life. Now she’s an asset to the Houston Museum of Natural Science’s malacology program, and she is full of stories.

Though Petway loved teaching, her passion was malacology. She had a brief stint as an interior decorator right after she finished school but then realized just how precious her shells were to her. The walls of model homes were too static for her, so Petway added some shells and coral specimens from her personal collection to liven things up.

“Well that went over really well and people wanted to buy them. I didn’t want to part with what I had! So that didn’t last too long,” Petway said.

She joined the Houston Shell Club (now the Houston Conchology Society) when she was 16 years old and never looked back. Soon, she was dragging her husband around all over the world looking for rare and exotic specimens. The couple met by coincidence near a family member’s bayhouse, and Petway knew they would get married after just a few months.

“I said, ‘I collect and buy seashells. I go places where there are shells, land snails, freshwater mollusks. That is my scope for life. If I take a vacation, it’s going to be some place like that. And I will continue to buy shells with money I earn. If that’s not ok, if you can’t deal with that, then let’s just be friends and forget this,’” Petway said. “And he said, ‘You know, if you can’t beat them, you join them.’ So he started buying shells, too! He’s as big a collector as I am.”

The pair were together on an uninhabited island in the Solomon Islands chain in 1972 when Petway had an encounter with a venomous cone snail, a group of gastropods that Petway says is her favorite family of mollusks. These snails are carnivores that use venomous barbs loaded with a cocktail of neurotoxins to kill prey. Even today, there is no antivenin. According to Petway, the way to survive is to load up on antihistamines so you keep breathing and use meat tenderizer to draw out the venom.


Petway discusses the anatomy of an octopus and other cephalopods in the Strake Hall of Malacology.

Petway was collecting specimens in small jars when she saw a cone snail scurrying along the reef. Recognizing it as venomous, she picked it up from the base with her right hand, pointing the aperture and barb down and away from her hand as she maneuvered to get a jar and open it.

At that time, another cone snail appeared, and Petway couldn’t resist. She transferred the snail to her other hand, picked up the new specimen and put it in the jar. At around that time, she felt a shooting pain in her left hand.

Petway looked at her left hand and saw that the cone snail had emerged, swung around and stung her on her pointer finger three times. She was 30 miles from the nearest airplane, three miles from the nearest habited island, and too far away for modern medicine to help. Of course, the first thing she did was put the snail in the jar for safe keeping; she still has it to this day.

“I thought, ‘Whoa, I don’t feel good.’ My head was hurting, my eyes were starting to get fuzzy, I was having a hard time breathing, my heart was pounding, and it was then that I accepted that, ‘Dang it, I’ve been stung!’” Petway said.

She hurried to the shore, took lots of antihistamines, wrapped meat tenderizer in a papaya leaf around her finger, and laid down. At that point, she was having difficulty walking, things were blurry, and her breathing was labored.

Petway thought, “‘Well if this is it, I went a really cool way.” What else can you say at a time like that?

The next day, the headache was still there, but her vision had cleared. The headache would remain for about a month, and it was over 10 years before Petway regained full use of her pointer finger.


Petway explains the features of the Australian trumpet shell, the single largest shell in the world and the crown jewel of the Strake Hall of Malacology. Petway estimates that the snail who made the shell was more than 100 years old.

Petway began volunteering at the Houston Museum of Natural Science in 1999 when John Wise was the curator of the Strake Hall of Malacology. When Wise left in 2005, Vice President of Collections Lisa Rebori asked Petway if she could fill in for a while.

“I said sure, of course! At that point, I had been through the whole collection and had pretty much self-cataloged everything that we had and had even started rearranging,” Petway said. “I just kind of started one day a week helping out, and I’ve been here ever since, and you can’t run me off.

“I eat and sleep this job. I absolutely love what I do. I love coming into the museum every day.”

Petway has led the way in a massive undertaking to revamp the Strake Hall of Malacology. Already known around the world as the premier collection of shells, HMNS has over 2.5 million specimens in storage and is working on purchasing more. The new hall will feature more rare specimens and more educational information about mollusks and their habitats.

“There is so much to learn about these animals, and that’s what we want to teach in this new hall. They’re not just pretty, and they are beautiful, but the animals that makes the shells are even more beautiful,” Petway said.

Petway is very passionate about conservation efforts for the world’s oceans and is a strong believer that education is a great method to promote the importance of these habitats. She is hopeful that the new hall will help convey that message to future generations.

It’s something she’s been seeing her whole life.

Food chains link the creatures of coastal ecology

Don’t stick your hand in that shell! You don’t know who might be home. It could be a carnivorous snail or a “clawsome” crab. Take a look at our Texas state shell, the lightning whelk or left-handed whelk, which feeds on bivalves like oysters and clams. Perhaps the snail that makes the shell is still hiding inside, or perhaps the shell is home to a hermit crab. Unlike most crabs, hermit crabs use the shells of snails as homes to protect their soft bodies.

Hermit Crab

Hermit crab taking residence in an empty lightning whelk shell.

Texas is home to some fascinating creatures, and our coast is no exception. In addition to the Gulf side beaches, there are salt marshes, jetties and the bay to investigate. Our coastal habitats are just waiting to be explored, and with the right gear, you can see organisms at every trophic level. (You knew I was going to talk about food chains, didn’t you?) 


Lightning whelk snail retracted into its shell, operculum blocking the opening.

Most folks will notice some of the upper-level consumers: birds like pelicans and gulls. Who could miss the gull snatching your unattended hotdogs? Or the pelicans plummeting into the water face first to catch fish? Maybe you’ve noticed fishermen along the beach as they pull in small bonnethead sharks. Some animals may require good timing and tons of mosquito repellent to see, like our rare and critically endangered Kemp’s ridley sea turtle. If you pay attention, there are even rattlesnakes catching mice that are feeding on insects and plants in the dunes!Food Web

As you follow a food pyramid from the apex down to the base, top predators like humans and sharks feed on the organisms in the level below. There you might find the larger bony fish we feed on, like redfish or snapper, and below them you can find some of the crustaceans and mollusks they feed on in turn. Crustaceans, like our blue crabs, stone crabs, and the smaller ghost crabs, often scavenge in addition to feeding on mollusks, worms, or even plant matter. Many of our mollusks are filter feeders, like oysters, pulling algae and plankton from the water. Finally, at the base of the food pyramid, there are the producers. The phytoplankton and algae make their own food with energy from the sun.

A food chain pyramid is a great way to show different types of food chains on one example. I used a pyramid created by my friend Julia and drew examples of food chains from our coast on it. One side has the trophic levels on it and the other three sides have example food chains. What’s on the bottom of the pyramid? The Sun, of course!Pyramid

Coastal ecology isn’t just about sand, shells, and dodging gulls. It’s also about the interactions between plants, animals, and their environment. The plants anchor the dunes, the dunes protect and replenish the beach sand, the sand houses animals like mole crabs and mantis shrimp, and we get to enjoy it when we protect it.

If tracking home beach sand in your shoes, car, towels, and suits doesn’t excite you, our new Hamman Hall of Coastal Ecology may be just the air-conditioned trip to the coast you need on a scorching summer day in Texas. Members, come join us Memorial Day weekend to see wonders of the Texas coastline!

Fear the Snail: Inside the vicious world of the predatory gastropod

So snails suck, right? They’re boring and slow and they don’t do anything cool. Some of them make pretty shells that you find on the beach, but they’re pretty much slimy and gross and basically not interesting at all.

Said no one ever. At least not those who understand the world and daily life of snails. They’re tough, vicious, and sometimes terrifying in their adaptations to help them feed and protect themselves, especially in the case of marine snails, which can be as varied in shape, size, and color as the imagination.

“There are about 30,000 known species of snail,” said Gary Kidder, HMNS Discovery Guide and snail expert. “They’re a ‘Walt Disney’ class: if you can dream it, they can do it.”


Slipper snail radula. Credit: Eric Heuple

Known in the science community as gastropods, meaning literally “stomach foot,” snails feed using a rasp-like tongue called a radula. Like most animals, the teeth vary from species to species based on what particular type of food the snail eats. In carnivorous snails, these teeth are like fish hooks that tear the flesh from their prey. Imagine having your skin licked off by a giant cat’s tongue! Terrible.

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The largest snail shell in the world, on display in the Strake Hall of Malacology.

Snails are not always small; they can grow to be massive. The Australian trumpet, or Syrinx aruanus, produces shells that can be as big around as your thigh. Measuring more than 30 inches in length, the record-holder for biggest snail shell in the world is on display in the Strake Hall of Malacology at the Houston Museum of Natural Science. It looks like you could fit a football inside this bad boy.


Lightning whelk. Credit: DixieHwy

Predatory snails use some barbaric tactics to kill and eat their prey. There’s no saving a bivalve caught by a lightning whelkBusycon perversum (incidentally, the state shell of Texas). The lightning whelks pries open clams, wedging its soft foot between the halves of its shell, then it uses its radula to scrape out the clam a piece at a time. Kind of like a stranger kicking down your door and coming into your house to get you. Frightening.

That’s just the beginning. The moon snail, in the family Naticidae, bores into the shells of mollusks and crabs with its radula and an acid secretion. That’s right: acid. It melts a tiny hole through its prey and licks out its insides with its tongue. No thank you!


Moon snail. Credit: Chris Wilson

To stun or kill their prey, many marine snails use some of the strongest venoms on Earth. The teeth in the radula of the geography cone, or Conus geographus, are modified to carry a venomous sting that disrupts insulin in its victims. Like a revolver loaded with up to twenty hypodermic needles (instead of six bullets), the cone snail harpoons its prey, sometimes with several stings in a matter of seconds.

“The venom gives you diabetes, basically,” Kidder said. “It makes you loopy. And if they’re able to hurt something our size, a fish, it’s usual prey, isn’t going to be an issue for it.”


Conus geographus. Credit: Patrick Randall

The harpoon of the C. geographus can penetrate human skin and sometimes gloves and wetsuits depending on its size. A single sting from a Conus snail can cause muscle paralysis, difficulty breathing, and death. No antivenin exists; victims must be hospitalized until the venom wears off. Don’t pick these suckers up unless you’ve got comprehensive health insurance!

Scientists, however, see the cone snail’s venom as an opportunity for medicines, and are working to synthesize compounds from its unique chemical cocktail as treatments for a variety of diseases.


Carrier snail. Credit: James St. John

Conus isn’t the only gastropod with potential benefit to humanity. The carrier shell, in the family Xenophoridae, Greek for “bearing foreigner,” uses a type of “concrete” to attach foreign objects to itself, reinforcing its own shell as it grows. The snail’s building media include other shells, pebbles, small pieces of coral, and in some instances human refuse like bottle caps. Scientists have even discovered new species from the shells attached to Xenophora.

“This is an aquatic saltwater snail that makes a cement that ‘dries’ underwater,” Kidder said. “If we can figure out how it does that, the economic possibilities are wild!”

So next time you see a land snail leaving a trail of slime, or a shell on the beach that once belonged to a marine gastropod, remember that in its own world, this slimy, slow-moving creature is a rock star.

Mala-whaaa? Discover the incredible world of mollusks in the Strake Hall of Malacology

One of the most awesome parts of working for a Museum (especially one as large as ours) is how many people you get to meet and work with – all with something different that gets them excited about science! It’s easy to celebrate your inner geek when you can find fellow geeks who you can geek out with in a geeky fashion while geekily reveling in unique parts of the Museum.

You could ask anyone here and they’d be able to tell you which part of the Museum brings this out in me: the Strake Hall of Malacology.

“Mala-whaaaa?” you may ask.

Malacology is the study of mollusks, an incredible group of creatures that includes octopi, scallops, and my favorite, snails (but more on them later). They’re invertebrates belonging to the phylum Mollusca, and there are over 85,000 species of them in the world!

These invertebrates all have three features in common but are otherwise extremely diverse. They have a mantle containing a cavity used for breathing and excretion; a radula, which is used for feeding; and the same structure to their nervous systems, with two pairs of nerve chords: one serving the internal organs and another for locomotion.

Mollusks are also able to use their internal organs for multiple purposes. For example, their heart and kidneys are used in their reproductive, circulatory, and excretion systems.

Mollusks are more varied than any other phylum. Think about it: squids, octopi, cuttlefish, nautili, clams, mussels, oysters, conch, slugs, snails — they all have many diverse species and yet they’re all still mollusks! And this is due, in part at least, to how long they’ve been around. While there’s still significant scientific debate about their precise lineages, we know that they’ve been around since the Cambrian period (541 to 485 million years ago). This has allowed them to diversify to fit in many, many niches all around the world — from the depths of the ocean to mountain tops.

Now for my favorite: SNAILS! Perhaps it’s because of my name (Gary, like Spongebob’s pet snail) but I think snails are really cool. They account for 80% of mollusks, and are perhaps the most diverse of them all. They’re found everywhere, in part because some have evolved to have gills while others have lungs.

But that’s not all! Some species with gills can be found on land, others with lungs are found in freshwater — with a select few even found in marine environments! They’re in ditches, deserts, large bodies of water and everywhere in between. Most are herbivores, but there are also omnivores and predatory snails. They’re also found in many sizes, from giant African land snails 35 cm in length to some just 1.5 mm long.

So come to HMNS to the Strake Hall of Malacology to learn everything there is about these marvelous mollusks!