Type — Mollusca.
Class — Gastropoda.
Superfamily — Planorboidea.
Family — Planorbidae.
Genus — Anisus.
— Anisus vorticulus [Troschel, 1834] — Little Whirlpool Ramshorn Snail. Family Planorbidae. Waters of Central and Eastern Europe. The body is greyish-purple, disc-shaped, slightly curved. The shell includes 5-6 whorls and reaches a diameter of 5-8 mm. They feed on microalgae and dead organic matter. These inconspicuous little snails appear sooner or later in many aquariums. Their presence is often noticed only by chance, as they are one of the smallest creatures. They are hermaphrodites. They reach sexual maturity at 1 year of age. Young snails appear in about two weeks (depending on water temperature). pH 7-8; dH up to 25°; Water temperature up to 25°C.
Genus — Helisoma.
— Helisoma nigricans [Spix, 1827] — Brazilian Ramshorn Snail. Family Planorbidae. (Eng. Red Ramshorn Snail, Brazilian Black Snail). Distributed in the tropics of South America. The wild ancestor of this mollusk has a brown coloration, however, albinos — bright red individuals — are most common in aquariums. Its red mutant form with a red shell is widespread. The shell is spiral in the form of a disc, up to 18 mm in diameter. The tiny tongue of the mollusk is dotted with small teeth that help it obtain food. Crawling on plant leaves and glass, snails constantly scrape soft algae, bacterial mucus with their radula-like tongue, and pick up food scraps, helping to maintain cleanliness.
Mollusks cannot cope with heavy algal growths. Their undoubted plus is that they never, even when hungry, eat plants. Having no special water requirements, snails reproduce quickly, laying small transparent clutches of eggs, from which young individuals appear in 8-14 days. Eggs are laid on stones, plant leaves, aquarium walls, and other underwater interior items. Like all tropical snails, it is heat-loving, maintenance temperature is 22-28 degrees.
Superfamily — Planorboidea.
Family — Bithyniidae.
Genus — Bithynia.
— Bithynia tentaculata [Linnaeus, 1758] — Mudalia / Tentacled Lagoon-Snail. Family Bithyniidae. Small aquatic snails distributed in rivers and lakes throughout Europe. Somewhat similar to the river snail (Viviparus), a representative of the closely related family Hydrobiidae. A small snail, shell height 12 mm, width 7 mm, with a conical shell provided with a calcareous operculum; tentacles are thread-like.
The color of the thin translucent shell is brown, olive, or dark grey, depending on the geographic region, separated by well-defined sutures, spire is blunt, with yellowish pigment in the mantle, the marbling of which is visible through the thin walls. They usually have 5 whorls, the last of which is very large. The body is black to dark brown and covered with round orange-yellow-gold spots. A rather small head with a snout resembling a muzzle. The foot is light grey when viewed from below.
Both river snails and Bithynia always stay at the bottom of the water body and do not float to the surface, unlike pond snails and ramshorns. In case of danger, they close the shell with an operculum, which serves as an excellent protective shield for these snails. There are geographic forms with minor differences due to adaptation to habitat features: — B. tentaculata bottnica; — B. tentaculata codia; — B. tentaculata excavata; — B. tentaculata gigas; — B. tentaculata producta;
A peaceful snail, it spends most of its time hiding in shelters, sometimes burrows into the substrate, and is more active at night. Bithynia belong to gill-breathing snails that extract oxygen from water using a gill apparatus hidden under the shell. Due to aquatic respiration, Bithynia are very sensitive to water quality and die much faster under adverse conditions than pond snails and ramshorns. It is advisable to keep them in a group in an aquarium rich in plants and decorative elements such as stones and driftwood.
Not suitable for a tropical aquarium; suitable for aquariums with a temperate and subtropical climate, with an abundance of aquatic flora, low water movement, and a good oxygen level. Not suitable for aquariums where too thorough cleaning and substrate siphoning are carried out. Water hardness must be high enough for the shell to be strong. Can withstand low temperatures, although the optimum is 15-22°C. Feeds mainly by water filtration. Bithynia readily eats green algae coatings on underwater objects, rotting plants, and dead fish.
Dioecious. In the aquarium, they reach sexual maturity at 4 months. Unlike the river snail, Bithynia reproduces by laying eggs on aquatic plants, roots, and stones. Its clutch has a very peculiar shape and is easily distinguishable from the clutches of other mollusks: it consists of hexagonal eggs arranged in a double row and enveloped in a gelatinous substance, forming an oblong mucous cord. They live in the aquarium for up to 1.5 years.
Superfamily — Cerithioidea.
Family — Pachychilidae.
Genus — Brotia.
— Brotia pagodula [Gould, 1847] — Pagoda Snail, Spiny Snail, Horned Armour Snail. Family Pachychilidae. “Pagoda snail”, “Spiny snail”, “Horned Armour snail”, “Melania Pagodula”. Thailand, Myanmar. Maximum size up to 5.5 cm. Prefer running water (well oxygenated) in fast-flowing rivers; extremely rarely can this snail species be found in lakes. A conical snail with spines around them arranged in a line. Their antennae are thread-like and have a visible horn.
These mollusks are very beautiful and unusual. They have various color variations of both the body and the shell. The shell is quite thick, conical with 5-6 well-defined whorls, length from 18 to 55 mm, width from 13 to 26 mm, with numerous hollow spines spiraling on top. The suture stands out clearly, strong rib structures. Color ranges from dark brown to yellowish, sometimes with dark stripes. The inner lining of the shell is grayish to cream-colored, with thin, slightly brown stripes sometimes visible. The body color of the snail varies from plain dark grey to light yellow with a pearlescent sheen and light spots; the foot is somewhat lighter, with light speckles. Spines are of darker shades than the rest of the shell.
Non-aggressive and compatible with most fish. Can become victims of loaches, cichlids. They suffer from loneliness; it is better to keep them in a small group of 2-4 individuals. Most of all they like to crawl on stones, though they need time to adapt, after which they will come out of hiding and begin their main activity — eating various growths and algae. They lead a nocturnal lifestyle: during the day they partially or completely burrow into fine-grained substrate. Adult snails are less active than young ones. Adult snails are very slow; observing them is interesting, but you need patience. Sometimes the mollusk closes up for the whole day and lies on the bottom without signs of life. They cling tightly to surfaces (it is better to move them on small stones), because trying to tear them off the glass can pull the mollusk out of its shell and kill it.
They need a strong current with high oxygen content, regular water changes, temperature of 20-25°C, dH up to 15°; pH 7.0-8.0. Prefer stones and hard substrates. Should not be placed in new aquariums devoid of algae. Their diet consists of algae, phytoplankton, dead leaves, and plants. In the aquarium, they eat mainly algal growths on glass and stones, as well as bottom-feeder food tablets and vegetables. Due to their slowness, they tolerate poorly a low presence of algae on glass, decorations, and the bottom. For the same reasons, they should not be combined with other gastropod species that may compete for nutrients. If the snails start eating higher plants in the aquarium, it means they do not have enough food. The diet can be supplemented with dry food high in spirulina.
Dioecious, but there are no external sexual characteristics. Breeding this snail in a home aquarium is difficult; they produce abundant offspring that die off quickly. There are no cases of successful breeding in the aquarium. In home conditions, it is sometimes possible to achieve snail reproduction, but no more than once a year. Life expectancy is 2-5 years, depending on water temperature.
Identification: Pagoda Snail — Brotia pagodula.
Genus — Faunus.
— Faunus ater [Linnaeus, 1758]. Family Melanopsidae. “Devil Thorn Snail”. Distributed throughout Asia, Malaysia, the Philippines, Java, and New Guinea. This is a magnificent conical and long shell, about 6-7 cm long and 2 cm wide. The shell is needle-shaped, with up to 18 fine spiral sutures, dark brown or glossy black. The body can be marble-grey, and there are specimens with partially grey and yellow-orange coloration.
The foot is lighter than the body, grey-black, sometimes yellow-orange, can be marbled, with a chestnut operculum framed with light dotted lines. The foot is round and brighter than the body, bordered with bright spots. Eyes are located at the base of the tentacles. Peaceful. It willingly lives in fresh water, however, it is tolerant of brackish water.
Adult snails are not so active; they often hide and burrow into the sand for a long time. However, when food appears, they come out to feed. It should not be kept in a general aquarium with fish, otherwise you will not see it. They are not interested in plants, they may only nibble on moss a little. It likes to live in fresh water, but can also live in slightly brackish water. The larvae need salt water, where they feed and grow. Unfortunately, breeding this interesting snail in the aquarium is impossible because its eggs require seawater. Temperature 24-31°C.
Superfamily — Cerithioidea.
Family — Potamididae.
Genus — Cerithidea.
— Cerithidea scalariformis [Say, 1825] — Mangrove Snail. Family Cerithideidae. North America and Cuba. Inhabits river mouths or coastal mangrove estuaries. The shell is elongated and conical, spiral clockwise with more than 7 whorls. On each whorl, there are numerous prominent and fine ribs that create the appearance of a spiral staircase. The shell is brown and cream, with lighter ribs. Body coloration is grayish, yellowish, or cream-colored.
Juveniles are constantly in the water, while adults can often sit on coastal plants and mangrove roots. A peaceful species, it can be kept in both freshwater and brackish water aquariums. Substrate made of fine sand, where they will hide and breed. Not demanding of oxygen content, but the water must be very hard. Spends a lot of time digging in the substrate, more so at night. They feed on detritus on plants and algae found on the substrate, and also accept raw and boiled vegetables. The optimal temperature is about 30°C. Water salinity is an important factor for their reproduction.
Genus Neothauma, Genus Pachymelania, Genus Potamopyrgus, Genus Thaia, Genus Thiara.
Genus Anodonta, Genus Corbicula, Genus Dreissena, Genus Sphaerium. 
