The trochus snail (Trochus spp.) earns its place as a dutiful saltwater aquarium clean-up crew member. They’re also attractive to keep around the tank. (Who doesn’t love combining form and function?) You don’t need to stretch to manage the gastropods, either. It’s the best of every world – provided you snag the proper snail from the fish store.
Table of Contents: Trochus Snail Care
If you already keep other gastropods, you’re set for trochus snails. But it doesn’t hurt to refresh yourself on the basics. And if you’ve never contemplated adding snails to your saltwater aquarium, this is the perfect opportunity. (You don’t know what you’re missing) These links will walk you through everything you need to know.
- Quick Facts
- Description of the Trochus Snail
- Trochus Snail Lifespan
- Creating the Ideal Trochus World
- Trochus Snail Diet
- Trochus Snail Behavior and Tank Mates
- Breeding the Trochus Snail
- Pros and Cons
- For More Information
Quick Facts
- Common Names: Trochus snail, Turban snail, Top shell snail, Black foot trochus, Zebra trochus snail
- Scientific Names: Trochus spp.
- Size: 1-3 inches (2.5-7.6cm)
- Minimum Tank Size: 10 Gallons (38L)
- Reef Safe? Yes
- Care or Experience Level: Easy
- Preferred Diet: Herbivore
- Original Part of the World: Indo-Pacific
Description of the Trochus Snail
The first thing people recognize in a trochus snail is the cone shape of the shell. The sharp point and flat bottom stand out from other species. And if you want to take the time to count, trochus snails usually have around 8-10 whorls (the fancy term for the turns that grace the shell). The shells look stunning, and they’re popular with jewelry makers and souvenir sellers. (Minus the snail, of course)
A shiny, polished shell comes in bands of maroon, red, or purple. Your average aquarium trochus usually obscures those colors with a healthy coat of algae, though. They ARE snails, and they move so slowly algae colonizes the shell. It gives them a fuzzy appearance and adds shades of green and grey to their colorful home.
Now, turbo snails ALSO boast cone-shaped shells. It’s easy to get the two confused if you don’t know what to look for. You can compare sizes, but that isn’t reliable. It’s better to look at the foot of the snail. Trochus snails possess a black foot with a white or beige underside. Turbo snails? Their entire foot’s white. It’s the easiest way to tell the two apart.
Trochus snails possess a unique ability to right themselves. They can flip back up when they fall (or get knocked over by a predator). It’s a defensive trait that protects against attack. Not to mention saving aquarists from constantly dipping their hand into the tank to rescue a tipped snail. Turbo snails lack this ability. (Not that you want to flip snails over just to figure out which species they are. That’s just plain mean)
As for size, it depends on the species. And there are over THIRTY species out there. Most hobbyists don’t know which they’ve brought home. The snails range anywhere from 1-3 inches (2.5-7.6cm) by the time they’re full-grown. (Turbo snails average smaller, but that might mislead you if you end up with a bitty tyke) Unless the fish store provides complete identification, you never know what size the snail will top out. Here are four popular examples to give you an idea of what to expect, though:
| Species | Shell Size |
| Trochus radiatus | 0.6-1.5 inches (1.5-3.8cm) |
| Trochus histrio | 1-2 inches (2.5-5cm) |
| Trochus maculatus | 1-2.5 inches (2.5-6.4cm) |
| Trochus noduliferus | Up to 3 inches (7.6cm) |
Trochus Snail Lifespan
Trochus snails pop up on reefs throughout the Indo-Pacific. It’s a far cry from their original distribution around southeast Asia. Over the past century, ballast water has carried individuals further and further throughout the Pacific. Now they cover a much broader range.
And since you can age a snail by examining the rings laid down inside the shell, monitoring their growth is easy. The species are SLOW to grow. They don’t reach maturity for several years. But then they enjoy a lifespan of over 15 years.
There’s a catch, though. Size and environment loop into that life expectancy. The warmer the climate you find the trochus snail in, the better its chance to survive for extra years. The same with the width of the shell. Larger species tend to outlive their smaller cousins.
Creating the Ideal Trochus World
While trochus snails used to confine themselves to the western Pacific, now you can find them venturing into the Indian Ocean and down to northern Australia. The age of the snail determines where on the reef you’re likely to spot that cone shell. Smaller juveniles prefer the shallow intertidal zone. It keeps them out of reach of most of their predators. As they age and grow, they move further out on the reef. But these gastropods don’t venture any deeper than 65 feet (20m). They need to stay where the sunlight offers the best algae growth.
These cone shell-dwelling snails also prefer rocky shorelines. They CAN move around on the sand, but it’s not their preferred substrate. Instead, they’ll climb to the closest rock or coral structure and continue their search for food.
It makes setting up your trochus snail habitat a cinch. All they’ll ask of you is live rock to explore. The crevices, caves, and pock-marked surface will keep their tentacles busy, searching for the next source of algae to chow down on. (And, face it, even at top speed, it’s going to take them a while to get from one end of the structure to the other)
Of course, you need a cycled aquarium to start. Trochus snails – like most invertebrates – are sensitive to nitrates and other wastes. If you attempt to introduce this gastropod into a new tank, you’ll find yourself with an attractive, EMPTY cone shell. (Once the snail decomposes, anyway)
You should also offer a few caves in the rock large enough for your trochus snail to retreat inside. They’re nocturnal. And, yes, they can withdraw into the shell, but it’s best if they have somewhere to park the shell before retiring. This prevents them from expending energy flipping over when curious tank mates nudge them during the day.
Trochus Snail Tank Size
Obviously, trochus snails come in a variety of sizes. And you’ll see plenty of advice suggesting you can keep a single snail per 2-3 gallons (8-11L) of water. Seems reasonable enough. It’s not like that cone shell displaces much room. And even the most impressive trochus snail isn’t going to zoom around your tank. (No one’s found the Turbo of trochus snails yet)
However, these snails pack monstrous appetites into those squishy bodies. The more an animal eats, the more waste it produces. Not to mention you need to provide the food to keep a stomach filled. If you err on the small side, you’ll end up with a snail slowly starving to death.
Your best bet is to go no smaller than 10 gallons (38L) for ONE trochus snail. You’ll provide plenty of room for your attractive cone shell to explore, feed, and hide out. And you won’t impact the water quality in the process. It’s the nicest thing you can do for your gastropod. You’ll also find a boost in the resulting growth rate. (Something to consider, especially if you find yourself with pockets of algae around the tank)
Are Trochus Snails Reef-Safe?
Trochus snails possess a radula for feeding. The radula allows them to scrape algae from hard surfaces. It’s what makes them successful herbivores. And it makes them reef-safe if you’re considering adding them with your favorite corals.
The snails don’t have a taste for coral polyps. They won’t even touch coralline algae (something you might need to keep in mind). As they move along the live rock in your tank, they’ll ignore the fleshy tentacles.
However, you should still look over your tank with a critical eye. Most of the species stay small. So when they bump against a coral frag, it doesn’t budge. Others? They’re large enough to send a frag plug tumbling. You need to secure anything loose on your rockwork structures to prevent a shell bump.
Trochus Snail Diet
Most hobbyists start turning to snails for their grazing habits. And trochus snails fit the bill. These herbivores use their radula to tackle algae, cyanobacteria, and diatoms. Best of all, they get to algae while it’s still in the film stage (i.e., before it turns into a nuisance). They’re a perfect part of the clean-up crew.
Slow as they are, though, you’ll probably reach a point when they’ve eradicated your algae problem. (Or you may have more than one algae-eater at work) Then it’s time to offer supplemental food. This is easy enough to accomplish:
- Algae wafers
- Nori
Unfortunately, trochus snails DON’T like hair algae. They might snack on it here and there, but it’s not a favorite. If you’re struggling with hair algae, you’ll want to pick up turbo snails. The smaller, white-footed cousins will take care of that pest for you.
Trochus Snail Behavior and Tank Mates
You CAN find aggressive snails out there. But the trochus snail isn’t one of them. (Most herbivores fall on the peaceful side of the scale) The cone shells pop up on the reef in the evening and set to work, scraping up algae. They don’t bother anyone. When the sun comes up, they retreat into hiding.
Of course, that habit of righting themselves didn’t appear out of nowhere. Trochus snails learned to fix themselves out of necessity. Plenty of species find gastropods tasty. And how do you eat a snail? By getting around that tough outer shell. So the ability to get right-side-up saves the trochus snail from disaster (most of the time).
But an upside-down snail CAN signal concern. If you see your cone shell in the wrong position, it might mean they’re stressed. You should gently assist them back to a rock and then check your water parameters.
Don’t assume the worst, though. Sometimes these snails flip around for reasons no one understands. The behavior can last for days. Then the snail goes back to normal. (Even gastropods have weird quirks)
Knowing that, though, you don’t want to include known snail-eaters in your tank. It’s inviting the chance to wake up and find an empty shell in the morning:
- Crabs
- Rays
- Wrasses
That goes for hermit crabs, too. Not because hermits savor the taste of trochus snail, but because the gorgeous cone shell is too much of a temptation for the crustaceans to pass up. Hermit crabs will kill a snail to get at the shell. Even if you offer alternatives around the aquarium (always a good idea), that shell is simply too beautiful. Your hermit crab won’t be able to resist.
Luckily, other invertebrates have better manners. You’re in the clear if you want to keep trochus snails with any of the following:
- Cerith snails
- Conch snails
- Saltwater shrimp
- Turbo snails
Breeding the Trochus Snail
Trochus snails breed in captivity easily. That isn’t the problem. Getting the resulting larvae to survive to adulthood – now, that’s a different story.
You’ll have to roll the dice on whether you have a male or female trochus snail. There’s no way to tell the difference between the two from the outside. Of course, if you have a large enough tank, you can purchase a small group and hope for the best. They get along well together, so you should see positive results once everyone reaches sexual maturity (at least two years old).
In the wild, trochus snails breed around the new moon. You can replicate those conditions by adjusting your lighting conditions. You’ll see the snails moving higher in the tank. This helps disperse the gametes over a wider area. The gametes appear in the water as a white, hazy blur. Once fertilized, the eggs hatch into free-swimming larvae. And that’s where problems start.
Fish, coral, and other invertebrates LOVE snail larvae – as snacks. Most never survive the 3-7 days to metamorphose into the (miniature) adult form. And even if they DO, life in a saltwater aquarium when you’re the size of the head of a pin isn’t easy. Aquarists find baby snails swept into their protein skimmers and filters. (Not an ideal nursery)
Assuming your trochus snail babies survive, it takes them a year to achieve adult size. Not bad, all things considered. You just need to protect them that long!
Pros and Cons
Trochus snails meet the “form and function” requirements most hobbyists search for. And while they’re not difficult to care for, you still want to look at the pros and cons that come with the species.
Pros
- Trochus snails feed on algae, cyanobacteria, and diatoms; they even scrape away algae films.
- Unlike most gastropods, trochus snails can flip themselves right-side-up if they fall or end up knocked over.
- Trochus snails are easy to breed – though getting the resulting offspring to survive to adulthood requires some work.
Cons
- Trochus snails, as with any invertebrate, are sensitive to nitrate levels. You need to ensure you have a cycled aquarium.
- The acclimation process for trochus snails is SLOW. You need to take twice the time you would for a fish – close to 1.5 hours.
- Hermit crabs often target trochus snails to steal their shells.
For More Information
Maybe watching a trochus snail slide over a live rock formation isn’t on your top ten list of excitement. But they’re gorgeous invertebrates – if you do decide to take that time. And they help scrub your tank clean of algae. It makes them a handy addition to any reef tank. If you need a little more convincing, though, we’ve got you covered.
This YouTube video goes through everything you need to know about trochus snails:
Want to know about some of the best trochus snail tank mates?
Algae’s a constant problem in many saltwater tanks. What if your trochus snail needs a hand? These other algae-eaters would love to pitch in:
Conclusions
Trochus snails have a popular following – in and out of the aquarium world. It’s difficult to resist those beautiful shells. But they’re much better options as part of an ecosystem, even a miniature one. And when you see the benefits you’ll gain when they sweep away the algae in your tank? You’ll wonder how you ever coped without one (or ten).
References
- Shimek, R.L. 2004. “The Grazing Snails, Part 1: Turbo, Trochus, Astrea, and Kin.” Reefkeeping Magazine.
- Wolfenden, Dave. 2014. “Keeping Turbo and Friends.” Practical Reefkeeping.
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