Snails can be a very useful part of a reef tank, consuming algae, detritus and harmful microfauna that can make life difficult for your corals and fish. In a sense they act as a janitorial service for your tank, which is probably why teams of snails and other scavenging organisms are called the Cleanup Crew (CUC). However when janitors and cleaners are hired for a building you usually don’t need to worry about whether they’ll eat each other or the furniture once they’ve run out of lunch. Below we’ve provided you a survey of the snails you will come across most often for purchase or as hitchhikers, their quirks and advantages and what may and may not make them a good addition to your tank. This list is by no means exhaustive.
The Good
· Abalone: These voracious algae film eaters are best suited for a large tank with a film algae problem. Be aware that their locomotion has been known to scratch acrylic tanks and be sure to purchase a tropical variety as most Abalones live in temperate waters. They can lodge a foot into a crevice and become hard to relocate. Per @evolved, the only one typically seen in the aquarium trade is Haliotis asinina, which won't scratch an acrylic tank.
· Astrea Snail: These snails are good all-around cleaners with large appetites. They prefer hair algae (they won’t eat long strands) but they also eat green film, diatoms and cyano. They are great at cleaning algae covered live rock but require ample hiding places and room to roam. They also require extra time to acclimate to a tank but they can tolerate higher water temperatures than other snails once they’ve become accustomed. This snail is infamous for having trouble righting itself when it falls over, and if they fall and can’t right themselves their soft underparts will be picked at by crabs and fish. Make sure your Astreas don't come with some predatory Pyramidellid snails attached to them (see below).
· Bumblebee Snails: An attractive carnivorous snail that thrives most effectively in old, established tanks. They won’t eat algae but are a great sand sifter and will eat detritus, bristle worms and other organisms in the sand bed but it won’t decimate your microfauna like a starfish. Bumblebee Snails are often considered not worth the trouble mainly due to their habit of harassing corals, however a lot of the difficulties in keeping bumblebee snails can be reduced by supplemental feeding of brine shrimp or other frozen meaty foods.
· Cerith Snail: An omnivorous snail that serves as a great addition to a tank because of its varied diet. Ceriths will eat almost anything, readily consuming detritus, uneaten fish food, film algae, diatoms, hair algae and cyano. Because of this wide diet and a voracious appetite ceriths tend to do best in well established tanks and are great for routine tank cleaning. These snails are also excellent sand sifters and will bury themselves in the sand. While they don’t appear very active they are nocturnal and do most of their activity at night. It is difficult to have a self-sustaining colony of Ceriths, as they tend to lay their eggs on the glass in which case the eggs are frequently eaten by other tank dwellers or removed by the filtration system or aquarist.
· Chestnut Turbo: These snails are powerhouses when it comes to cleaning algae and detritus from your tank. They have an attractive, top- or turban-shaped shell with well defined and bead-dotted spirals and a reddish brown coloration. These snails also prefer ample hiding places and large amounts of space in which to graze, preferably amongst live rock.
· Cowrie: While these snails are attractive with patterned glass like shells they are not good additions to reef tanks as they normally stay on live rock and pick at soft corals and anemones as they grow. However they can be decent additions to FOWLR (Fish only with Live Rock) Tanks for their aesthetic qualities.
A Fighting Conch.
This photo is courtesy of and used with permission from WorldWideCorals, ©2019, All Rights Reserved.
· Fighting Conch: Contrary to its aggressive sounding name, the moderately easy to care for Fighting Conch is relatively peaceful with its tank mates. The name comes from how male conchs fight for territory, so it’s probably safe to say you should only keep a single Fighting Conch unless you are skilled at sexing them. Fighting Conchs require open, deep sand beds where they can forage for food, in addition these voracious eaters often require supplemental feeding in smaller systems.
A Margarita Snail.
This photo is courtesy of and used with permission from WorldWideCorals, ©2019, All Rights Reserved.
· Margarita Snail: These snails are great hair algae eaters and are peaceful towards coral. Unfortunately they are also dedicated hair algae eaters and can often starve if not enough hair algae is present, however their diet can be supplemented by dried seaweed. They may also require calcium supplementation to promote shell growth. They do not like warm temperatures, 76F is their maximum temperature for survival. Just to be clear, these snails come from temperate waters, and they will not survive long at tropical reef tank temperatures.
A Nassarius Snail.
This photo is courtesy of and used with permission from WorldWideCorals, ©2019, All Rights Reserved.
· Nassarius Snail: Unlike other carnivorous snails the Nassarius Snail is purely a scavenger. Nassarius is a genus of reef-safe snails common in the aquarium trade. They need fine sand and will bury themselves and move around keeping your sand bed clean; they will also roam into crevices in live rock in search of food. They will eat detritus and uneaten food but will not decimate the microfauna in your sand bed. A larger variety is the Super Nassarius snail, which can grow up to 1” in size. You can supplement the diet of Super Nassarius with brine or mysis shrimp or pieces of fish or scallops.
· Nerite Snail: Most Nerites live in fresh water as opposed to salt water. Nerites are primarily diatom eaters that also consume film and hair algae and cyano. They are small so can get into hard to reach spaces but this means that they don’t consume algae very fast. They are quite long lived under good conditions and are quite effective when stocked together with Cerith Snails. Per @evolved, Nerite Snails in the marine aquarium trade are collected from tidepools, and they will not hesitate to climb out of your tank if it's uncovered to look for another "tidepool".
· Stomatella Snail: These are odd-looking snails that looks like slugs on a half shell. They are reported to be reef-safe and a good addition to your CUC. Per @evolved, they usually arrive as hitchhikers.
A Trochus Snail.
This photo is courtesy of and used with permission from WorldWideCorals, ©2019, All Rights Reserved.
· Trochus Snails: These relatively easy to care for snails are large and are big eaters of film algae and diatoms but don’t readily eat hair algae. As they are large you should ensure your corals and rock work are well secured to avoid a bulldozing snail knocking them over. They are short lived but also quick spawning in most aquariums but be careful and don’t overstock them as they can quickly eat out their food supply. It is recommended that you only keep one snail for every two or three gallons of aquarium water. The Banded Trochus variety is one of the most popular types, and they appear to breed easily in a reef tank.
· Turban Snails: Requires a great deal of calcium for its shell and an adequate calcium level should be maintained. Generally fairly hardy and does well in an established aquarium with many hiding places. They are more tolerant of light as they grow and slowly become more active during the day.
A Mexican Turbo Snail.
This photo is from the Reef2Reef archives courtesy of @Reefer Reboot, ©2019, All Rights Reserved.
· Turbo Snails: Large snails that can eat massive amounts of algae. They prefer film algae but will chew their way through all forms including macro algae. Due to their size they can knock over significant pieces of live rock or larger corals with ease. The Mexican Turbo variety is subtropical and won’t live very long in most tanks. Watch for dead or dying Turbos as with their large size they can pollute a tank quickly. They eat so much algae that the recommended number per tank is 1 per 25lbs of live rock. You can supplement their diet with dried seaweed.
The Bad
A Babylonian Snail hitchhiker.
This photo is from the Reef2Reef archives courtesy of @Coralfish1701, ©2019, All Rights Reserved.
· Babylonian Snails: These snails are frequently mislabeled and sold as species of Nassarius though this is not the case and they have no relation. While these snails can look quite beautiful with their brown and cream shells they are a predatory species and can eat your herbivorous snails making them a risky addition to any tank. Nevertheless, some aquarists (@Robb1414) report liking them and not experiencing any problems with them.
· Crown Conch: Often confused with Fighting Conch snails, these snails are predatory and will often eat herbivorous snails in your tank, leaving algae uneaten and reducing the overall effectiveness of your cleanup crew. For this reason Crown Conchs are not at all recommended but unfortunately are often sold as Fighting Conch and other types of Conch that aren’t as dangerous to your tank environment.
· Flamingo Tongue: A very beautiful snail that unfortunately feeds solely on Gorgonian coral.
· Keyhole Limpets: Most known keyhole limpets are carnivores that will feed on coral. Generally you should be very wary about adding any limpets to your tank without being certain of their species and/or diet. What type of limpet you have makes a big difference. @evolved reminds us that what we call "limpet" is comprised of many different species of snail. They aren't all bad, but it's best to err on the side of caution.
· Murex Snails: These snails are shaped like stout Conchs but you are best avoiding them if you can. All species of Murex are aggressively predatory and will eat your herbivorous snails and may feed on your corals and any other small or slow lifeforms you have in your tank.
· Olive Snails: Predatory snails that have started to pop up in the hobby recently. They feed on small bivalves, microfauna and small snails as well as carrion when they get the chance. The main issue is that they aren’t really effective cleaners and could pose a threat to other snails.
· Pyramidellid Snails: These snails are in the family Pyramidellidae. They are sometimes called pyramid snails. They are tiny micromollusks that are typically predatory and parasitic to other larger bivalve mollusks. They come to the attention of reef aquarists who have Tridacna clams in their tanks, and enough of them can kill a clam. There are also varieties known to bother oysters in temperate waters. The are generally described as looking like grains of rice.
· Queen Conch: While herbivorous, these snails tend to grow to massive size, 12 inches long and 4 inches tall and need a large area to survive and will bulldoze most rock formations. Not recommended.
· Vermetid Snails: Vermetid snails are stationary. They cement themselves somewhere and send out little tubes and spider-web-like strands of mucous to trap microorganisms or detritus floating by. The problem with them is that they impede the growth of coral and can prevent fish from eating algae normally. It's usually recommended to try to get rid of them if you see one because they can multiply and create a major problem in a closed system. Vermetid snails are "snails," but they are sometimes referred to as tube worms or worm snails because they stay in one place. They are molluscs, and they are within the Gastropoda family. And some even have an operculum--the door that a snail can pull shut to protect him or herself.
· Whelk: Whelks look very similar to Nassarius but are a predatory group that primarily eat clams but will often eat other snails as well. Not recommended for the reef tank.
The Ugly
· Ilyanassa obsoleta: Unfortunately popular on E-Bay due to the ease of collecting them, these omnivorous snails will eat smaller herbivorous snails. It also isn’t good for the snail to be in a warm reef tank as they are normally found on the northeast coast of North America, and putting them in the wrong (too warm) type of tank can be condemning them to a slow death. Worst of all these snails often carry parasites such as trematode fluke that can infect both fish and humans. There is some controversy over whether this snail should be in the genus, Nassarius.
We hope that our little survey above has provided you with useful information that will help you stock your tank with the prettiest, most pragmatic clean up crew you can acquire.
~~~~~~~~~~~~~~~~~~
Note from the Editor: One of our forum members, @ca1ore, reviewed this before publication and reminded me that A) there are plenty of intertidal snails (like the last one mentioned) that will try to climb out of tanks, B) that snails can be bothered or preyed upon by certain crabs or fish, and C) snails that dig around in the sand can quickly decimate your helpful microfauna. So, be aware of these things when choosing snails.
~~~~~~~~~~~~~~~~~~
References
· https://secure.liveaquaria.com/product/aquarium-fish-supplies.cfm?c=497+526
· https://joejaworski.wordpress.com/2013/10/03/whats-the-best-snail-for-a-reef-tank/
· https://www.aquariumcreationsonline.net/snails.html
· https://www.reefcleaners.org/bad-snails
· https://www.melevsreef.com/articles/whelk-versus-nassarius
· http://reefkeeping.com/issues/2006-11/mg/index.php
· http://blogs.thatpetplace.com/thatfishblog/2008/09/15/naughty-marine-snails/#.XLjJAzBKiUk
· https://www.advancedaquarist.com/blog/vermetid-snails-harm-coral-reefs-with-multiprong-attack
· http://reefkeeping.com/issues/2006-09/jf/index.php
· http://www.dfo-mpo.gc.ca/science/aah-saa/diseases-maladies/pyrasnoy-eng.html
· https://www.melevsreef.com/critter/stomatella
· http://reefkeeping.com/issues/2005-11/rs/index.php
· http://www.iucngisd.org/gisd/species.php?sc=1321
~~~~~~~~~~~~~~~
We encourage all our readers to join the Reef2Reef forum. It’s easy to register, free, and reefkeeping is much easier and more fun in a community of fellow aquarists. We pride ourselves on a warm and family-friendly forum where everyone is welcome. You will also find lots of contests and giveaways with our sponsors.
~~~~~~~~~~~~~~~
Author Profile: Peter Steckley
Peter Steckley is a freelance science writer based in Calgary, Alberta, Canada. When he's not studying reef aquariums or testing out new recipes on his family, he's usually reading or enjoying the latest video game releases.
The Good
· Abalone: These voracious algae film eaters are best suited for a large tank with a film algae problem. Be aware that their locomotion has been known to scratch acrylic tanks and be sure to purchase a tropical variety as most Abalones live in temperate waters. They can lodge a foot into a crevice and become hard to relocate. Per @evolved, the only one typically seen in the aquarium trade is Haliotis asinina, which won't scratch an acrylic tank.
· Astrea Snail: These snails are good all-around cleaners with large appetites. They prefer hair algae (they won’t eat long strands) but they also eat green film, diatoms and cyano. They are great at cleaning algae covered live rock but require ample hiding places and room to roam. They also require extra time to acclimate to a tank but they can tolerate higher water temperatures than other snails once they’ve become accustomed. This snail is infamous for having trouble righting itself when it falls over, and if they fall and can’t right themselves their soft underparts will be picked at by crabs and fish. Make sure your Astreas don't come with some predatory Pyramidellid snails attached to them (see below).
· Bumblebee Snails: An attractive carnivorous snail that thrives most effectively in old, established tanks. They won’t eat algae but are a great sand sifter and will eat detritus, bristle worms and other organisms in the sand bed but it won’t decimate your microfauna like a starfish. Bumblebee Snails are often considered not worth the trouble mainly due to their habit of harassing corals, however a lot of the difficulties in keeping bumblebee snails can be reduced by supplemental feeding of brine shrimp or other frozen meaty foods.
· Cerith Snail: An omnivorous snail that serves as a great addition to a tank because of its varied diet. Ceriths will eat almost anything, readily consuming detritus, uneaten fish food, film algae, diatoms, hair algae and cyano. Because of this wide diet and a voracious appetite ceriths tend to do best in well established tanks and are great for routine tank cleaning. These snails are also excellent sand sifters and will bury themselves in the sand. While they don’t appear very active they are nocturnal and do most of their activity at night. It is difficult to have a self-sustaining colony of Ceriths, as they tend to lay their eggs on the glass in which case the eggs are frequently eaten by other tank dwellers or removed by the filtration system or aquarist.
· Chestnut Turbo: These snails are powerhouses when it comes to cleaning algae and detritus from your tank. They have an attractive, top- or turban-shaped shell with well defined and bead-dotted spirals and a reddish brown coloration. These snails also prefer ample hiding places and large amounts of space in which to graze, preferably amongst live rock.
· Cowrie: While these snails are attractive with patterned glass like shells they are not good additions to reef tanks as they normally stay on live rock and pick at soft corals and anemones as they grow. However they can be decent additions to FOWLR (Fish only with Live Rock) Tanks for their aesthetic qualities.
A Fighting Conch.
This photo is courtesy of and used with permission from WorldWideCorals, ©2019, All Rights Reserved.
· Fighting Conch: Contrary to its aggressive sounding name, the moderately easy to care for Fighting Conch is relatively peaceful with its tank mates. The name comes from how male conchs fight for territory, so it’s probably safe to say you should only keep a single Fighting Conch unless you are skilled at sexing them. Fighting Conchs require open, deep sand beds where they can forage for food, in addition these voracious eaters often require supplemental feeding in smaller systems.
A Margarita Snail.
This photo is courtesy of and used with permission from WorldWideCorals, ©2019, All Rights Reserved.
· Margarita Snail: These snails are great hair algae eaters and are peaceful towards coral. Unfortunately they are also dedicated hair algae eaters and can often starve if not enough hair algae is present, however their diet can be supplemented by dried seaweed. They may also require calcium supplementation to promote shell growth. They do not like warm temperatures, 76F is their maximum temperature for survival. Just to be clear, these snails come from temperate waters, and they will not survive long at tropical reef tank temperatures.
A Nassarius Snail.
This photo is courtesy of and used with permission from WorldWideCorals, ©2019, All Rights Reserved.
· Nassarius Snail: Unlike other carnivorous snails the Nassarius Snail is purely a scavenger. Nassarius is a genus of reef-safe snails common in the aquarium trade. They need fine sand and will bury themselves and move around keeping your sand bed clean; they will also roam into crevices in live rock in search of food. They will eat detritus and uneaten food but will not decimate the microfauna in your sand bed. A larger variety is the Super Nassarius snail, which can grow up to 1” in size. You can supplement the diet of Super Nassarius with brine or mysis shrimp or pieces of fish or scallops.
· Nerite Snail: Most Nerites live in fresh water as opposed to salt water. Nerites are primarily diatom eaters that also consume film and hair algae and cyano. They are small so can get into hard to reach spaces but this means that they don’t consume algae very fast. They are quite long lived under good conditions and are quite effective when stocked together with Cerith Snails. Per @evolved, Nerite Snails in the marine aquarium trade are collected from tidepools, and they will not hesitate to climb out of your tank if it's uncovered to look for another "tidepool".
· Stomatella Snail: These are odd-looking snails that looks like slugs on a half shell. They are reported to be reef-safe and a good addition to your CUC. Per @evolved, they usually arrive as hitchhikers.
A Trochus Snail.
This photo is courtesy of and used with permission from WorldWideCorals, ©2019, All Rights Reserved.
· Trochus Snails: These relatively easy to care for snails are large and are big eaters of film algae and diatoms but don’t readily eat hair algae. As they are large you should ensure your corals and rock work are well secured to avoid a bulldozing snail knocking them over. They are short lived but also quick spawning in most aquariums but be careful and don’t overstock them as they can quickly eat out their food supply. It is recommended that you only keep one snail for every two or three gallons of aquarium water. The Banded Trochus variety is one of the most popular types, and they appear to breed easily in a reef tank.
· Turban Snails: Requires a great deal of calcium for its shell and an adequate calcium level should be maintained. Generally fairly hardy and does well in an established aquarium with many hiding places. They are more tolerant of light as they grow and slowly become more active during the day.
A Mexican Turbo Snail.
This photo is from the Reef2Reef archives courtesy of @Reefer Reboot, ©2019, All Rights Reserved.
· Turbo Snails: Large snails that can eat massive amounts of algae. They prefer film algae but will chew their way through all forms including macro algae. Due to their size they can knock over significant pieces of live rock or larger corals with ease. The Mexican Turbo variety is subtropical and won’t live very long in most tanks. Watch for dead or dying Turbos as with their large size they can pollute a tank quickly. They eat so much algae that the recommended number per tank is 1 per 25lbs of live rock. You can supplement their diet with dried seaweed.
The Bad
A Babylonian Snail hitchhiker.
This photo is from the Reef2Reef archives courtesy of @Coralfish1701, ©2019, All Rights Reserved.
· Babylonian Snails: These snails are frequently mislabeled and sold as species of Nassarius though this is not the case and they have no relation. While these snails can look quite beautiful with their brown and cream shells they are a predatory species and can eat your herbivorous snails making them a risky addition to any tank. Nevertheless, some aquarists (@Robb1414) report liking them and not experiencing any problems with them.
· Crown Conch: Often confused with Fighting Conch snails, these snails are predatory and will often eat herbivorous snails in your tank, leaving algae uneaten and reducing the overall effectiveness of your cleanup crew. For this reason Crown Conchs are not at all recommended but unfortunately are often sold as Fighting Conch and other types of Conch that aren’t as dangerous to your tank environment.
· Flamingo Tongue: A very beautiful snail that unfortunately feeds solely on Gorgonian coral.
· Keyhole Limpets: Most known keyhole limpets are carnivores that will feed on coral. Generally you should be very wary about adding any limpets to your tank without being certain of their species and/or diet. What type of limpet you have makes a big difference. @evolved reminds us that what we call "limpet" is comprised of many different species of snail. They aren't all bad, but it's best to err on the side of caution.
· Murex Snails: These snails are shaped like stout Conchs but you are best avoiding them if you can. All species of Murex are aggressively predatory and will eat your herbivorous snails and may feed on your corals and any other small or slow lifeforms you have in your tank.
· Olive Snails: Predatory snails that have started to pop up in the hobby recently. They feed on small bivalves, microfauna and small snails as well as carrion when they get the chance. The main issue is that they aren’t really effective cleaners and could pose a threat to other snails.
· Pyramidellid Snails: These snails are in the family Pyramidellidae. They are sometimes called pyramid snails. They are tiny micromollusks that are typically predatory and parasitic to other larger bivalve mollusks. They come to the attention of reef aquarists who have Tridacna clams in their tanks, and enough of them can kill a clam. There are also varieties known to bother oysters in temperate waters. The are generally described as looking like grains of rice.
· Queen Conch: While herbivorous, these snails tend to grow to massive size, 12 inches long and 4 inches tall and need a large area to survive and will bulldoze most rock formations. Not recommended.
· Vermetid Snails: Vermetid snails are stationary. They cement themselves somewhere and send out little tubes and spider-web-like strands of mucous to trap microorganisms or detritus floating by. The problem with them is that they impede the growth of coral and can prevent fish from eating algae normally. It's usually recommended to try to get rid of them if you see one because they can multiply and create a major problem in a closed system. Vermetid snails are "snails," but they are sometimes referred to as tube worms or worm snails because they stay in one place. They are molluscs, and they are within the Gastropoda family. And some even have an operculum--the door that a snail can pull shut to protect him or herself.
· Whelk: Whelks look very similar to Nassarius but are a predatory group that primarily eat clams but will often eat other snails as well. Not recommended for the reef tank.
The Ugly
· Ilyanassa obsoleta: Unfortunately popular on E-Bay due to the ease of collecting them, these omnivorous snails will eat smaller herbivorous snails. It also isn’t good for the snail to be in a warm reef tank as they are normally found on the northeast coast of North America, and putting them in the wrong (too warm) type of tank can be condemning them to a slow death. Worst of all these snails often carry parasites such as trematode fluke that can infect both fish and humans. There is some controversy over whether this snail should be in the genus, Nassarius.
We hope that our little survey above has provided you with useful information that will help you stock your tank with the prettiest, most pragmatic clean up crew you can acquire.
~~~~~~~~~~~~~~~~~~
Note from the Editor: One of our forum members, @ca1ore, reviewed this before publication and reminded me that A) there are plenty of intertidal snails (like the last one mentioned) that will try to climb out of tanks, B) that snails can be bothered or preyed upon by certain crabs or fish, and C) snails that dig around in the sand can quickly decimate your helpful microfauna. So, be aware of these things when choosing snails.
~~~~~~~~~~~~~~~~~~
References
· https://secure.liveaquaria.com/product/aquarium-fish-supplies.cfm?c=497+526
· https://joejaworski.wordpress.com/2013/10/03/whats-the-best-snail-for-a-reef-tank/
· https://www.aquariumcreationsonline.net/snails.html
· https://www.reefcleaners.org/bad-snails
· https://www.melevsreef.com/articles/whelk-versus-nassarius
· http://reefkeeping.com/issues/2006-11/mg/index.php
· http://blogs.thatpetplace.com/thatfishblog/2008/09/15/naughty-marine-snails/#.XLjJAzBKiUk
· https://www.advancedaquarist.com/blog/vermetid-snails-harm-coral-reefs-with-multiprong-attack
· http://reefkeeping.com/issues/2006-09/jf/index.php
· http://www.dfo-mpo.gc.ca/science/aah-saa/diseases-maladies/pyrasnoy-eng.html
· https://www.melevsreef.com/critter/stomatella
· http://reefkeeping.com/issues/2005-11/rs/index.php
· http://www.iucngisd.org/gisd/species.php?sc=1321
~~~~~~~~~~~~~~~
We encourage all our readers to join the Reef2Reef forum. It’s easy to register, free, and reefkeeping is much easier and more fun in a community of fellow aquarists. We pride ourselves on a warm and family-friendly forum where everyone is welcome. You will also find lots of contests and giveaways with our sponsors.
~~~~~~~~~~~~~~~
Author Profile: Peter Steckley
Peter Steckley is a freelance science writer based in Calgary, Alberta, Canada. When he's not studying reef aquariums or testing out new recipes on his family, he's usually reading or enjoying the latest video game releases.
