Nassarius snails (Nassarius sp.) are excellent scavengers and great sand sifters. They will eat various kind of organic material and help to aerate the sandy substrate in your tank. Therefore, if you are looking for a cleanup crew for a saltwater aquarium, you have found it!
Nassarius snails will be an excellent addition to your saltwater tank. These snails are super easy to keep and feed. In addition, they are very resilient and can tolerate a wide range of water parameters. All these qualities make them also a great choice for beginners.
Although, Nassarius snails are distributed worldwide on the ocean bed and there are 35 recorded species. In this article, I am going to talk about 2 most popular species in the aquatic hobby: Nassarius Vibex and Nassarius distortus. The reason is that these species act the same way and share the same feeding habits.
Note: Unfortunately, there is one issue in our hobby. Nassarius Snails are almost never labeled other than “Nassarius Snail”. What species is this!? Nobody knows. However, it is extremely important.
Nassariidae species can be herbivorous, carnivorous and scavengers. For example, Bullia digitalis feeds on dead organic matter deposited by the waves, Nassarius obsoletus feeds on organic material (plant or animal) deposited in the intertidal zone. Nassarius pyrrhus feeds on moribund molluscs, fishes and decapod crustaceans. Nassarius obsoletus is omnivoros scavenger, etc.
Quick Notes about Nassarius Snail
||Zombie snails, Super Tongan snail, Bruised nassa, Common Eastern nassa|
|Scientific Name||Nassarius sp.|
|Tank size (minimal)||5 gallons (~20 liters)|
|Size||1 – 2 cm (~0.4 – 0.8 inches)|
|Optimal Temperature||22 – 26°C (~72°F – 80°F)|
|Water type||SG = 1.023 – 1.025|
|Optimal PH||8.1 – 8.4 (7.5 – 9)|
|Optimal KH||5 – 12|
|Nitrate||Less than 20 ppm|
|Diet||Omnivorous / Carnivorous|
|Temperament||Peaceful (with caution)|
|Life span||up to 3 years|
|Color Form||Mostly white, yellow, sandy, dark and brown|
Description of the Nassarius Snails
The Nassarius snails are pretty small-sized. The largest specimen can grow up to 2 cm (about 0.8 inches). However, usually, they are 1 – 1.5 cm long (0.4 – 0.6 inches).
Their shells have the “heavy” sculpting with flaring lip near the opening of the shell, and usually sharp, unworn tip.
The shell coloration depends on the specimen and can usually have white, yellow, sandy, dark, and brown (light and/or dark). In most specimens, the shell features either ridges or bumps.
The Nassarius Snail has a proboscis/siphon (mouth), which looks like an elephant’s trunk. They also use it for breathing and smelling.
Behavior of the Nassarius Snails
They spend most of their time buried, with only the siphon poking up like a periscope. However, as soon as they smell the dead organic matter, the Nassarius snails emerge immediately from the substratum and move quickly toward the food. According to different studies of these species, they have a complex olfactory system. The detection of “prey” can occur from a distance of 1.5 m and 2.0 meters.
They are not slow movers, these snails move rapidly around the aquarium waving the siphon, after identification of the origin of the odor.
Note: Aquarists also call Nassarius snails “Zombie snails”. Once you see how they move their siphon and all rise up out of the sand, you will understand the joke.
They always rebury themselves in the sand after the complete consumption of large meals.
In general, they are quite peaceful snails. However, there are also reports of attacking other snails.
Sexing of the Nassarius Snails
Nassarius snails are not hermaphrodites. They have distinct male and female individual organisms. The only problem is that all females are affected by imposex. Meaning that they also develop nominal male organ. Therefore, biologists base the sex determination upon other characters such as:
- males: the presence of seminal vesicle;
- females: presence of a capsule gland and vulva.
Unfortunately, it is possible to do only under laboratory conditions.
Feeding Nassarius Snails
Nassarius snails (Nassarius Vibex and Nassarius distortus) are opportunistic eaters of dead organic matter. These species do not eat algae. They eat all the leftovers at the bottom of your sand bed and big time on detritus. If you see them on top of the sand searching, you should know that they are very hungry.
These snails eat a lot of food in relation to their body weight and do it very fast. For example, biologists calculated that some species could consume between 50 to 60% of body weight on average 8 – 12 minutes.
Note: In the wild, rapid consumption of large amounts of food decreases the risk of predation, since animals clustered around the food are a potential food source for predators.
In the aquarium, they will eat leftover food, detritus, and etc. Nassarius snails are very good at scavenging. However, if you have many snails or there are not enough leftovers and naturally occurring food. It would be better to supplement their diet with all sorts of meaty food, like frozen brine shrimps, freeze-dried larvae, and cut up pieces of fish and seafood. Otherwise, they can turn cannibalistic.
Interesting fact: Some Nassarius species (for example Nassarius reticulatus), as many whelks, are usually regarded as an obligate scavengers, and a single meal may sustain an individual for several days.
Keeping Nassarius Snails
Nassarius snails are very easy to care for. In nature, they display a broad tolerance to changes of salinity and temperature. They are hardy enough to survive in impacted and polluted areas. Therefore, your tank will be a paradise for them.
Tank size really does not matter. You can easily keep 1 – 2 Nassarius snails in a 5-gallon tank.
Keep the temperature around 22 – 26C (72 – 80C), the specific gravity at 1.023-1.025, the pH within the 8.1-8.4 range, and the water hardness around dKH 8 – 12.
The species lives upon a wide variety of substrata ranging from coarse sand, mud to silt. Studying this family, showed that less than 5% of the species are adapted to the rocky environment. Hard substrate (rocks, gravel) prevents them from burring that can stress them a lot.
Note: Nassarius snails will also help to aerate the sandy substrate in your aquarium as they sift through the substrate while searching for food. It will also help to reduce the growth of slime algae or cyanobacteria on the substrate surface.
Do not forget to acclimate them before putting in your tank. Read my article “How I Drip Acclimate Shrimp and Why” and use the same principle for the snails.
Be careful with copper (read more info about it) and you should not have a problem with them.
Breeding Nassarius Snails
According to the study, sexual maturity occurs in males of 11.5mm and larger, and females of over 15mm.
The life cycle of the Nassarius snails is characterized by the presence of planktonic veligers (larvae) that emerge from benthic capsules.
The planktonic larvae require 1–2 months to complete metamorphosis and settlement. That is a relatively long planktonic phase compared to other gastropods.
The Nassarius snails usually attach their egg capsules to hard substrates (the glass of an aquarium, rocks, decorations, etc). Each egg capsule can contain from thirty to – several hundred embryos, which developed until the veliger stage is reached.
Hatching takes place after about 9 – 15 days of encapsulated development. The complete larval development and metamorphosis throughout 25 – 35 days.
Note: Keep in mind that range of microalgal foods (Dunaliella sp., Chlorella sp., Nannochloropsis sp., Isochrisis sp., Skeletonema sp, Rhodomonas) will not be a good choice for the larvae. In all experiments, they all died. You will have to prove a compound food, a liquid suspension for filter-feeder organisms for that.
Nassarius Snails and Tankmates
Be very careful with Hermit crabs and clams. There are numerous reports describing Hermit crab’s (Halloween Hermit Crab, Blue Leg Hermit Crab, etc.) attempts to eat Nassarius Snails or take over their shells. However, you can decrease the level of aggression (interest) if your crab has a lot of food and plenty of empty shells.
There are also some conflicting data about Nassarius Snails compatibility with snails.
Some people say that they will be fine with other snails, starfishes, shrimp, hermit crabs, and any peaceful fish. They do not attack any healthy living creature, that this species eat only dead, dying, or the extra food that fell to the bottom of the tank. Only, if you start running into the food problem they might start eating each other or other snails.
Unfortunately, there are also reports that Nassarius Snails went after Nerite snails, Stomatella snails, Trochus Snails, etc. the moment they smelled them. What makes it even worse is that they were not starving.
There is a hypothesis that the real culprits are not Nassarius Snails but predatorial Welk snails. Obviously, Welk snails are unwanted snails in a reef system.
Difference between Nassarius Snails and Welk snails
- Welk snails are aggressive and bigger compared to Nassarius Snails.
- Their siphon looks like it has tattoos.
- They have a protective shell on the tail to seal themselves in the shell when in danger.
- Their shells are dark with whitish blotches.
- Some Welk species do not burry themselves beneath the surface of the sand. However, usually, they do.
Nassarius Snail is a saltwater snail that does not require special care. They will clean your aquarium and aerate the sandy substrate in it.
They are considered to be a quite hardy, useful, and peaceful snails.
- Demaintenon, M.J. Analysis of reproductive system ontogeny and homology in Nassarius vibex (Gastropoda: Buccinidae: Nassariinae). Moll. Stud.v.67, p.37-49, 2001.
- Feeding behavior of Nassarius vibex (Gastropoda: Nassariidae)” by Helena Matthews-Cascon and Carlos Meirelles. Article January 2012
- Physiological responses and scope for growth in a marine scavenging gastropod, Nassarius festivus (Powys, 1835), are affected by salinity and temperature but not by ocean acidification Haoyu Zhang1, Paul K. S. Shin1,2, and Siu Gin Cheung1,2*. ICES Journal of Marine Science (2016), 73(3), 814–824. doi:10.1093/icesjms/fsv208
- Assessment of the effects of ocean acidification and warming on the swimming behavior of Nassarius reticulatus larvae: microscopic study of the locomotor organ by Joana Fonseca and Daniela Freitas. February 2019
- A visual guideline for the determination of imposex in Nassarius reticulatus and Nassarius nitidus. By Nagore Cuevas and Joana Larreta. January 2011.
- Laboratory spawning, larval development and metamorphosis of the marine snail Nassarius reticulatus (L.) (Caenogastropoda, Nassariidae) By Valerio Zupo and Francesco Paolo Patti. Article in Invertebrate Reproduction and Development · July 2009
- Pu C, Li H, Zhu A, Chen Y, Zhao Y, Zhan A (2017) Phylogeography in Nassarius mud snails: Complex patterns in congeneric species. PLoS ONE 12(7): e0180728. https://doi.org/10.1371/pone.0180728
- The Escape of Veligers from the Egg Capsules of Nassarius obsoletus and Nassarius trivittatus (Gastropoda, Prosobranchia) by Jan Pechenik. Article in Biological Bulletin. December 1975