Tylomelania perfecta

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Tylomelania perfecta, also known as the Chocolate Rabbit Snail, is a large freshwater snail native to Sulawesi, Indonesia. Its elongated, often chocolate-brown shell and long tentacles give it the distinctive appearance associated with “rabbit snails.” This bottom-dwelling species moves slowly across hard surfaces and acts as a grazer of algae and detritus in the aquarium. It prefers warm, well-oxygenated and mineral-rich water, along with a stable layout offering shelter. Its specialized availability makes it a sought-after gastropod among aquarists. A mature aquarium with natural biofilm and suitable water chemistry is important for long-term success.

General species description

Tylomelania perfecta is a freshwater gastropod in the family Pachychilidae, associated with lakes and streams in Sulawesi. Like other Tylomelania, it has a relatively tall spiral shell and a body with a broad foot adapted to moving across rocks, sand and submerged wood. It is most active when the lighting is reduced, although it may also travel during the day in a well-established aquarium. Its main activity is rasping biofilms and collecting food particles deposited on the bottom. It is not a fast burrowing snail or a predator. Water stability is important because the shell may deteriorate when pH or hardness is too low. In a peaceful community aquarium, it is generally unobtrusive and does not attack healthy plants. Reproduction is live-bearing, with young produced individually rather than from gelatinous egg masses. Provide enough bottom area so individuals can move freely and avoid constant disturbance.

Geographic origin and biotope

Country of reference: Indonesia. The species is associated with Lake Towuti in South Sulawesi, one of the ancient lakes in the Malili lake system. It inhabits shoreline areas and shallow zones where hard surfaces support biofilms, including rocks, submerged wood and plant debris. The water is warm and generally neutral to alkaline, with a useful supply of dissolved minerals. Natural areas combine sand, gravel and rocky substrates, with aquatic and shoreline vegetation varying from one site to another. In the aquarium, recreate clean, warm and well-oxygenated water without excessive waste accumulation. Fine sand or small gravel, rounded stones and a few roots are suitable. Its availability remains specialized in the aquarium trade, so it should be kept in an appropriate setup rather than with aggressive tank mates. Stable chemistry and regular maintenance are more important than strong water movement.

Precise locality and local name

The reference locality is Lake Towuti, in southeastern Sulawesi, Indonesia, within the Malili lake system. Shorelines, quiet bays and rocky littoral areas are the most relevant habitats for understanding its lifestyle. The commercial name Chocolate Rabbit Snail is widely used in the English-speaking aquarium trade; French aquarists may also encounter translated names such as chocolate rabbit snail or brown rabbit snail. The word “rabbit” refers to its long tentacles and expressive head, not to any relationship with mammals. Dense aquatic vegetation is not essential: surfaces covered with natural algae and biofilm are more valuable. A lid is recommended because Tylomelania may explore the upper part of the aquarium when conditions change or when food is scarce. Leave open areas on the substrate for movement and feeding.

Appearance and physical characteristics

Tylomelania perfecta has a tall, conical, spiral shell that is usually dark brown to chocolate, with a surface that may appear smooth or slightly sculpted depending on age and wear. The body is often lighter or more contrasting than the shell. Its head bears two long sensory tentacles, with eyes near their bases, explaining the name Chocolate Rabbit Snail. The foot is broad and muscular, allowing slow but effective movement across rocks and glass. Adult size can be impressive for an aquarium snail, so individuals need sufficient bottom space to move without being constantly disturbed. Natural differences in coloration should not automatically be interpreted as separate varieties. A pale, eroded or pitted shell usually indicates water that is too acidic, too soft or deficient in calcium. The shell and body should therefore be checked regularly. Good mineral availability supports shell growth and helps preserve its distinctive appearance.

General diet

In the wild, Tylomelania perfecta mainly grazes on biofilm, soft algae and microorganisms growing on submerged surfaces. It also collects organic particles and leftover food that reach the bottom. In an aquarium, a mature setup provides part of its diet, but this resource may not be sufficient, especially in a very clean or newly established tank. Supplement with invertebrate wafers, sinking vegetable-based foods and small portions of blanched zucchini, spinach or cucumber. A varied diet supports the foot and shell. Remove uneaten food if it remains for too long, since decomposing leftovers can damage water quality. Provide adequate calcium and minerals through sufficiently hard water or a suitable mineral source placed in the aquarium. Very protein-rich foods should not form the basis of the diet. Feed modest portions and observe whether the snails are actively reaching the food.

Essential data

• River of origin: Lake Towuti basin, Malili lake system
• Local name used: Chocolate Rabbit Snail; chocolate rabbit snail
• Origin of the scientific name: The genus name is formed from Greek roots; the Latin species epithet was assigned by the species authors
• Full-name etymology: Tylomelania refers to a knob or swelling associated with a dark mollusc; perfecta means perfect or complete in Latin
• Common/vernacular names: Chocolate Rabbit Snail; chocolate rabbit snail; brown rabbit snail
• Family: Pachychilidae
• Subfamily: Pachychilinae
• Name pronunciation: tie-loh-meh-LAH-nee-ah per-FEK-tah
• Discovery: Fritz Sarasin and Paul Sarasin, 1897
• Maximum adult size: about 10 cm
• Water temperature and pH: 26–30 °C; pH 7.5–8.5
• Waterway appearance and surrounding vegetation: warm lake shores, rocky substrates, sand, submerged wood and variable shoreline vegetation
• Typical tank mates: peaceful small Sulawesi fish; Tylomelania snails; peaceful shrimp
• Temperament and behavior: peaceful and slow-moving, mainly active at dusk and night; grazes surfaces
• Water depth: littoral areas and shallow sections
• Sexual dimorphism: difficult to distinguish externally
• Bottom structure and flow: sand, gravel, rocks and wood; calm to moderately moving, well-oxygenated water

In your aquarium

To succeed with Tylomelania perfecta, choose a mature aquarium with warm water and good oxygenation. Maintain alkaline pH and sufficient mineral content to protect the shell, while avoiding sudden changes. Provide rocks, roots and surfaces covered with biofilm, then supplement the diet regularly. Avoid fish that nip at the tentacles or constantly disturb the substrate. With these conditions and steady maintenance, this gastropod can become an unusual, useful and long-lived inhabitant in a layout inspired by Lake Towuti. Watch shell condition, body activity and feeding response as simple indicators of its well-being.