Radix rubiginosa, commonly known as the Ear snail, is another type of snail, which is gradually appearing in the aquarium hobby. These snails are excellent cleaners with a voracious appetite.
This species is very resilient and can tolerate a wide range of water parameters. It makes them suitable for almost any type of aquarium. At the same time, keep in mind that Ear snails are hermaphrodites. Therefore, they can reproduce at a rapid rate and become a problem.
If you are considering adding Radix rubiginosa to your tank, then you will definitely find this article helpful. In this guide, I gathered everything that is currently known about this species including ideal tank setups and how to care for them.
Quick Notes about Ear Snails
| Name | Ear snail |
| Other Names | European ear snails or Pokemon snails |
| Scientific Name | Radix rubiginosa |
| Water type | Freshwater/brackish |
| Tank size (minimum) | any |
| Keeping | Easy |
| Breeding | Easy |
| Size | 0.8 – 1 inches (2 – 2.5 cm) in length |
| Optimal Temperature | 64 – 86°F (18 – 30°С) |
| Optimal PH | 7.0 – 8.0 |
| Optimal GH | 8 – 30 |
| Optimal KH | 4 – 16 |
| Nitrate | Less than 80 ppm |
| Diet | Algae eater/detritivore |
| Temperament | Peaceful |
| Life span | up to 1 year |
| Color Form | Pale yellow to dark brown |
Etymology of Radix Rubiginosa
The genus name “Radix” is derived from the Latin word “Rādīx”, which means “Roots”. The root can be considered a synonym for base or foot.
The species name “Rubiginosa” comes from the Latin word “Rūbīginōsus,” which means “Rusty or rust-colored”
So, “Radix rubiginosa” essentially translates to “Rust-colored boot” which describes the snail’s characteristic reddish appearance or features.
Distribution of Ear Snails
Radix rubiginosa is native to Indonesia, Vietnam, and Indo-China
However, these snails have proven highly invasive because of wide environmental tolerances. As a result of trade in the pet and aquarium industry, particularly the trade in aquarium plants, this species is gradually expanding its habitat boundaries, displacing the local fauna.
For example, it can be found in Taiwan, China, Japan, Vietnam, Australia, Russia (Lake Baikal), the USA, and South Africa. This species has also been listed as a “hothouse” alien species in Great Britain, Ireland, and Israel.
Habitat of Ear Snails
Ear snails inhabit a wide variety of freshwater habitats, such as lakes, ponds, swamps, marshes, rice fields, small canals, ditches, etc. They generally prefer stagnant or slow-moving bodies of water.
Photo by H. Madsen (source)
Description of Ear Snails
Radix rubiginosa is a species of air-breathing freshwater snail. This is an aquatic pulmonate gastropod in the family Lymnaeidae, the pond snails.
- Size. Ear snails are relatively small in size. Adult individuals typically grow up to 0.8 – 1 inches (2 – 2.5 cm) in length.
- Shell. Their shell is elongated, cylindrical, broadly ovate, and dextral. There are 5 whorls; the last one is large and inflated. The body whorl is markedly swollen and forms the greatest portion of the shell. Sutures are moderately prominent.
- Aperture. The aperture is moderately large (4-5mm in width and 7-11 in height), wide, and semi-ovate to ear-like (Hence the name – Ear snails).
- Columella. It is generally twisted but not gyrate.
- Shell Color. The color of the shell varies from glossy pale yellow to dark brown.
- Body color. The mantle surface is mottled black with patches of pale white to yellow. There are also large unpigmented fields and stripes.
These snails are bimodal breathers, which means that they can get oxygen either through cutaneous respiration (i.e. directly through the skin) or through aerial respiration via a rudimentary lung (i.e. gas exchange with the atmosphere).
To perform aerial respiration, the snail must surface and open its breathing pore while contracting and relaxing the appropriate respiratory muscles.
Interesting fact: Do you know that snails have radula (tongue-like feeding organ) that generally consist of 80 – >100 overlapping rows of these teeth?
For a detailed description of Radix rubiginosa, you can refer to this scientific paper.
| Important: Historically, the shape and sculpture of gastropod shells have been considered to be a great way to distinguish species. Unfortunately, it does not work all the time with genes Radix and Lymnaea (For example, R. rubiginosa, and L. natalensis).
Some species can be so similar in appearance, that scientists can identify them only by using molecular techniques. |
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Lifespan of Ear Snails
Depending on the temperature, the lifespan of Radix rubiginosa can range from 5 months to 1 year. Results of the experiments showed that these snails lived for:
- 29 weeks at 68°F (20°C)
- 25 weeks at 77°F (25°C)
- 22 weeks at 86°F (30°C)
Typical Behavior of Ear Snails
Like most snail species, these snails are also nocturnal. They often spend the daytime hiding and resting.
Note: The nocturnal behavior is not uncommon for grazing invertebrates and is mainly associated with attempting to avoid visual predators whilst feeding.
They are absolutely peaceful, non-aggressive, solitary, and very shy animals. These snails prefer a calm aquatic environment and peaceful tank mates to be happy.
Ear snails are not natural diggers. Even when they can burrow in soft substrate, they do not move under it.
They can float by filling the cavity with air. To descend, they can compress the cavity and sink to the bottom.
These snails are known to climb on surfaces and explore their surroundings, including plants, rocks, and driftwood. Keep it in mind, especially, if the water level in your aquarium is very high.
Features:
- Social: No
- Active: At night
- Peaceful: Yes
- Burrowers: No
Diet of Ear Snails
These snails are omnivorous and great scavengers.
While they might not be a substitute for tank maintenance, Ear snails will definitely help you keep the tank clean
In aquariums, their diet consists mainly of grazing on biofilm and various types of algae that grow in the aquarium, including diatoms (brown algae), Green spot algae, Green Dust Algae, etc.
If you give them blanched vegetables (like carrots, sprouts, spinach, cucumber, zucchini, etc.), they will eat them as well.
Features:
- Diet Type: Mostly herbivore / omnivore
- Food Preference: Algae
You can read some of my related articles (the principle is the same with snails):
Are Ear Snails Plant Safe?
Yes, these are safe to keep in planted tanks. This species primarily feeds on algae and decaying plant matter, it usually does not consume healthy, live plants.
Caring and Keeping Ear Snails
Due to its high tolerance to water pollution and wide-ranging diet, Radix rubiginosa is regarded as one of the most successful invasive species in aquatic environments.
Therefore, keeping them in aquariums will not be a problem even for beginners.
Tank size:
Tank size does not matter for these snails. Ear snails can live basically in any nano tank.
Water Parameters:
Temperature: This species can tolerate gradual decreases in water temperature down to 50°F (10°C). However, their activity noticeably decreases at such low temperatures. According to the study, the ideal range of temperatures is anywhere between 64 – 86°F (18 – 30°С).
Note: Results of the experiments showed that this species displayed reproductive attributes and a temperature tolerance that was similar and in certain cases even exceeded the performance of the invasive Bladder snails (Physa acuta).
pH: Although these snails can be found in both alkaline and acidic waters, their optimal water pH is in the range of 7.0 – 8.0.
Note: If your water has a pH of less than 6.0 for weeks (months), it may have problems with shell formation. At low pH, calcium uptake is particularly difficult, which slows down and disturbs the formation of the shell.
Hardness: They will appreciate hard water KH > 4 and GH > 8.
Filtration:
No special requirements.
However, if you intend to breed Radix rubiginosa as live food for your fish and want to increase their population, you can use a basic sponge filter in their tank setup.
Lighting:
No special requirements.
All snail species are nocturnal creatures. So, they could not care less about it. Lighting should be adapted to the needs of plants (and/or algae if needed) in your tank.
Related article:
Substrate:
Even though Ear snails can be kept in any tank with any substrate, I would still recommend smooth gravel over any other type.
- These snails do not usually burrow.
- The main reason – it is easier to grow algae on them!
Reproduction of Ear Snails
These snails are hermaphrodites, meaning each individual possesses both male and female reproductive organs. This allows them to potentially fertilize themselves, although cross-mating with other individuals is more common.
Some breeding facts of Radix rubiginosa:
- They grow really fast and become mature at 2 months old.
- These snails lay capsules. The egg capsules are transparent. Each capsule may contain 10-20 eggs. The largest capsule had 134 eggs enclosed.
- The eggs are 0.9 mm in length and 0.7 mm in width. They are regularly oval. The egg cell is darker yellow.
- Depending on the temperature, incubation lasts 12 days at 50°F (10°C), 8 days at 77°F (25°C), and 6 days at 86°F (30°C).
- The highest hatching success is at 77°F (25°C).
- Results of the experiments showed that they have had 5 distinct peaks in fecundity. The most prominent fecundity peak occurs at 10 weeks (128 eggs per snail) while fecundity at 13 weeks is usually around 102 eggs.
- Embryonic development takes place entirely within the eggs from which the young hatched as crawling juvenile snails. There are 5 stages: cleavage, blastula, gastrula, trochophore, and veliger stage.
Ear snails and Suitable Tankmates
These snails are excellent feeders for Assassin snails, Crayfish, Loaches, Pufferfish, Oscars, etc.
Besides that, they can live and thrive in any community tank.
| Important: Do not collect these snails from the wild. The Lymnaeidae are one of the most widespread groups of freshwater snails and many of them act as intermediate hosts of important digenean trematodes (Fasciola spp.) and nematode (Angiostrongylus malaysiensis) that infect humans or livestock. |
In Conclusion
Ear snails are excellent scavengers and easy to care for. They are absolutely harmless creatures and can be safely kept in planted and/or community tanks.
Their small size allows keeping them even in the smallest tanks. The main problem though is that they are pretty hardy and prolific. Once established in the tank, it will be a problem to get rid of them, if you decide to do that.
|
Ear snails (Radix rubiginosa) |
|
| Pros | Cons |
| Tolerate freshwater and brackishwater | Not very decorative |
| Amazing algae eaters | Hermaphrodites and extremely prolific |
| Great cleaners | They do not aerate the substrate |
| Can reproduce in freshwater | |
| Peaceful | |
| Do not eat plants | |
| Excellent feeders for Assassin snails, crayfish, Pufferfish, etc. | |
Related articles:
- List of Freshwater Aquarium Snails. Pros and Cons
- 30 Frequently Asked Questions about Snails in Freshwater Tanks
- Benefits of Snails for a Shrimp Aquarium.
References:
- Nadasan, Devandren Subramoney. “The invasive potential of the freshwater snail Radix rubiginosa recently introduced into South Africa.” PhD diss., 2011.
- Dung, Bui Thi, Pham Ngoc Doanh, Dang Tat The, Ho Thi Loan, Bertrand Losson, and Yannick Caron. “Morphological and molecular characterization of lymnaeid snails and their potential role in transmission of Fasciola spp. in Vietnam.” The Korean Journal of Parasitology51, no. 6 (2013): 657.
- Appleton, C. C., and N. A. F. Miranda. “Two Asian freshwater snails newly introduced into South Africa and an analysis of alien species reported to date.” African Invertebrates56, no. 1 (2015): 1-17.