Common questions with a lot of possible answers – Water quality, mineral or vitamin difficiency, starvation, predation – but often the solution can be quite simple…it fell down and couldn’t get up. Snails crawl around all the time, but falling off of a surface and ending up with their shell on the sand can be a death sentence.
Most snails aren’t adapted to environments where there they may get flipped upside-down (like falling off the straight sides of an aquarium). They are from environments where they are either not climbing at all (like sand flats) or where if they do fall, they either roll until they are right-side-up again or fall where they can reach another surface and right themselves. Being upside-down for short periods of time won’t kill the snails, but it does leave them vulnerable to predation from tankmates, and they can’t feed or do any other normal snail things. Some snails can flip themselves over like acrobats, but others may need a hand if they get stuck.
Here are a few common aquarium species. Keep in mind that even those that are able to flip can still get stuck depending on their position and the terrain:
Turbo Snails (Turbo sp.): While some Turbo’s can flip themselves over, most struggle. These snails end up on their backs often since they tend to be glass-climbers and fall off frequently if startled. Their heavy shells cause them to be top-heavy, and if they fall into open sand or substrate it can spell disaster.
Margarita Snails (Margarita sp.): Another one of the common glass-climbers. Some will flip themselves over, but again the substrate or lack of reachable ornamentation can make the task impossible.
Nerite Snails (Nerita sp.): These snails tend to cling to surfaces well and usually don’t end up in a situation where they need to flip very often. If they do fall, they can usually flip themselves over with ease. The bigger problem with these is their habit of climbing completely out of the tank!
Trochus Snails (Trochus sp.): These have pyramid-shaped snails. Trochus Snails (also called Turbo Snails or Turban Snails by some) have the ability to right themselves pretty easily as opposed to some of their nearly identical cousins.
Astrea Snails (Astraea sp.): This is one of those nearly identical cousins. Astrea Snails are notorious for climbing, falling and dying. Always make sure they are right-side-up when you put them in your tank and flip them over if you see them overturned.
Nassarius Snails (Nassarius sp.): These snails don’t venture out of the substrate often. They usually have no problem flipping as they are quite agile and have a long and nimble foot. These are the break dancers of the snail world – they whip their foot around until they find something to grab onto or the momentum flips them over.
“Conchs” (Strombus sp., Lambis sp. and a few others): This is a very wide group. Their relative safety depends on the species, but most of the true conchs (Strombus sp. and Lambis sp.) are never really found climbing around so don’t usually have this problem. They are usually in or on the substrate. Some conchs have very ornate or heavy shells that can hinder their movement if they get stuck, but most others can usually use their strong foot to their advantage and don’t have too much trouble.
Cerith Snails (Cerithium sp.): There are many different types of cerith; some climb surfaces (and even out of the water like the Nerites) and some stay buried in the substrate. Because of their very cone-like body shape, they don’t often get stuck to where they can’t right themselves, but depending on the terrain, it can happen, especially if you have a lot of rock. Its a good idea to flip them over if you think one may be in trouble.
Cowries (Cypraea sp.): Cowries are climbers and are very good staying stuck. If they do happen to slip, there isn’t much they can do to help themselves. Their slit-like opening and shell-covering mantle gives them good suction on a flat surface, but not much torque to be able to allow them to flip. Larger, heavier cowries can be especially clumsy; they do need your help.
Other climbers – Starfish and Urchins: Customers also share concerns over these reef creatures and their mobility. Some starfish have suction cup-like tubes feet down each leg that they can control like hydraulics; urchins have rows of these tubed feet covering their entire bodies. It may take some time depending on the species, but a fallen starfish or urchin can usually flip themselves with little effort (although some assistance from you wouldn’t go amiss).
These are just a few examples of what the snails are capable of in the ideal aquarium environment. Research any new choices carefully, but when in doubt, just flip them yourself and help your snails survive.
Tiger Cowrie Snail image referenced from wikipedia and originally posted by Nhobgood