Mystery Snail (Pomacea Diffusa)

Mystery Snail, Spike-Topped Apple Snail, Mystery Apple Snail, Inca Snail

Distribution

This is a freshwater species that is widely distributed in the vast region of the Amazon in its natural conditions, both in flowing waters (rivers, streams, brooks) and standing waters (floodplains, lakes, ponds). Depending on the particular species / variety, the area of distribution may be smaller (e.g. Pomacea bridgesii bridgesii - occurs only in Bolivia, in Rio Grande and its tributaries) or larger (Pomacea bridgesii diffusa).

External Appearance

The taxonomy of the genus of these snails is quite complex due to the large number of color variations for each species, which have the same common names. This also applies to the Pomacea bridgesii, which was previously classified as two varieties (Pomacea bridgesii bridgesii and Pomacea bridgesii diffusa), but they are now regarded as two different species (Pomacea bridgesii and Pomacea diffusa). It is worth noting that the wild form of this species has a brown shell. Currently, the most popular color versions of this mollusk are: red-pink, striped shell, yellow shell, white shell, green shell, with a yellow, white or black body. Such color varieties can also be found in Pomacea diffusa. One thing is certain: the differentiation of individual species should not be based on the color of the shell or body of the snail, but on the shape of their shell (especially the angle at the suture, i.e. the angle between the upper edge of the opening and the adjacent shell seam). Pomacea diffusa is characterized by a conical shell up to 4cm in size, with 5-6 whorls, which are set flat. The angle at the suture is 90°. The opening is oval, which can be covered with a lid or not (the snail has the ability to hide the lid in the shell). Interestingly, this snail is prepared to breathe in any conditions. It has gills (on the right side of the shell) and lungs (on the left side of the shell) and is also equipped with a respiratory siphon. In this way, they can survive in oxygen-poor waters. However, it should be known that even in well-oxygenated waters, they emerge onto the surface to breathe. They most often use the siphon for this purpose. It is a long, flexible fold of the mantle cavity in the shape of a cylinder, located on the left side of the body, allowing the mollusk to breathe while it is fully submerged (only the siphon protrudes).

Disposition

This snail is mainly active at night, during the day it hides in shaded areas of the aquarium or burrows into the substrate. It is the only species of snail that doesn't eat healthy plants, even when there's nothing else to eat. It can comfortably be kept with shrimps and calm fish. Aggressive inhabitants, which could nibble on its very long tentacles, should be avoided. Natural predators are also not recommended. The population of these snails is very easy to control by systematically removing the eggs laid by them.

Aquarium

As for the living space, the size of the bottom surface of the tank is important here - the larger the better. Snails often go on long trips outside the aquarium, so it is necessary to have a tight cover. The water level should be such that our snails can easily lay eggs above it (unless we don't want this). The water should be settled - without chlorine (this is important when breeding all snails). Scattered light, hiding places, soft substrate seem to be a good idea. Effective filtration is required (the feces of these snails cause the water to become cloudy) or / and regular part water changes. As for the quality of water or its oxygenation, these snails are not very demanding. However, they can be a good indicator of the level of dissolved oxygen (if they stay just below the water surface practically all the time, it means that something bad is happening with the water). It is necessary to have an additional source of calcium in the aquarium.

Reproduction

This species is egg-laying, unisexual (for reproduction, we need a female and a male). Interestingly, these snails have the ability to change sex at any time. During copulation (internal fertilization), which can last up to several hours, the sperm is transferred by the male (it is stored in the semen reservoir of the female). Sperm can be stored by the female for up to a month until the eggs mature. Fertilization therefore occurs without the presence of the male - when laying eggs. The female lays eggs at night or at dawn. Eggs are laid above the water surface (usually on the glass or cover) individually, in a very dense group (like a cocoon), for several hours. After laying all the eggs (up to 200), the female falls into the water. Eggs should never be flooded with water, but they must be in a moist and warm environment (otherwise, they will dry out). Over the next few days, it can be seen how the cocoon changes - initially its color (from white to pink), then its size (the eggs swell). In the next stages, you can already observe gray, tiny shells. When the eggs mature (2-4 weeks, depending on the ambient temperature), the cocoon systematically decomposes, and small snails fall into the water. Little snails immediately start to feed, but most often they hide in the substrate. They hide there until their shell fully forms and hardens. The female snail can lay eggs multiple times, over a period of several weeks. Also, keep in mind that not all species of this snail lay their eggs above the water surface. The Asolene, Lanistes, and Marisa types do it in the water.

Food

These are herbivorous snails, which are happy to feed on algae and detritus (dead organic matter). They do not refuse fresh vegetables or food for herbivorous or bottom fish. The snail is adapted to feed on the water surface as well.