Chocolate Poso rabbit snail
Tylomelania perfecta
The Chocolate Poso rabbit snail (Tylomelania perfecta) is a large, live-bearing freshwater snail associated with Lake Poso on Sulawesi. In the aquarium trade it is often sold as a chocolate rabbit snail or Sulawesi snail. A trade label alone does not confirm its identity: the genus contains many forms and identification can be difficult. Aquarium references recommend warm, mineral-available, alkaline water, but hobby values and minimum tank sizes vary. This guide therefore gives a cautious working range without inventing a hardness target or volume minimum. The snail grazes on biofilm and microalgae but often needs supplementary food; a newly set-up or spotless tank is unsuitable. Genus-level research describes a brood pouch and live juveniles. Because trade animals may be wild-caught, provenance and responsible sourcing matter.
Plan your aquarium →At a glance
- Temperature
- 26–28 °C
- pH
- 7.5
- Diet
- Omnivore
- Adult size
- Approximately 4–6 cm
- Temperament
- Peaceful, May compete for food
About this species
Tylomelania perfecta (Mousson, 1849) is accepted by MolluscaBase/WoRMS (AphiaID 1062867). Its original combination was Melania perfecta. It is a freshwater gastropod in Pachychilidae from Sulawesi. Trade names such as chocolate rabbit snail do not always represent an independently checked identification; ask about origin and identification evidence when uncertain.
Natural habitat
Aquarium profiles associate the species with Lake Poso on Sulawesi, Indonesia. A specialist overview of Tylomelania describes species from Lake Poso, the Malili lake system and tributaries, on both hard and soft substrates. For Poso, it reports warm water and alkaline pH. This is ecological context, not a complete aquarium recipe. Sulawesi has multiple Tylomelania species and local forms, so a precise collection locality cannot be inferred from a trade name alone.
Aquarium and layout
Choose a stable, cycled aquarium with open bottom area, rocks and sheltered places. Maintain mature natural growth and provide supplementary food; a new or thoroughly cleaned tank may not offer enough to graze. The literature does not support a robust minimum volume for this exact species, so no litre minimum is stated. Allow for a snail around 4–6 cm and space to move across the substrate and hardscape. A calm, lightly stocked layout makes it easier to check that the animal is feeding.
Water conditions
Practical sources differ: one species profile gives 22–28°C, while a Tylomelania overview describes warm Sulawesi waters around 26–30°C. We therefore use only their overlap, 26–28°C, as a cautious guide, not a proven physiological limit. Lake Poso, the reported locality, is described with pH around 7.5; higher values from other Sulawesi lakes should not automatically be applied to this species. One aquarium profile gives contradictory advice. GH, KH and a validated pH interval are therefore left unspecified. Keep water chemistry stable, make minerals available and acclimate slowly.
Behaviour and group size
The snail generally moves slowly and grazes across surfaces; genus-level observations also describe resting periods and retreat into shade. Provide crevices and shaded areas. A specialist source reports that some hard-substrate Tylomelania may nibble intact plants, so do not assume this species is plant-safe. Other grazers may compete for biofilm. Avoid fish that nip tentacles or attack snails. These recommendations draw on profile and genus sources, not controlled trials with every potential tankmate.
Feeding
Species profiles describe diatoms, microalgae and bacterial biofilm as food. A specialist genus overview reports that Tylomelania may also accept spirulina powder, herbivore foods and vegetables; those observations apply to the genus and do not guarantee acceptance by every T. perfecta. Offer small supplementary portions and check that the snail actually eats. Remove leftovers. It is not a reliably self-sufficient algae cleaner. No catalogue product has been individually checked for acceptance and composition for this species.
Breeding
Tylomelania have separate sexes and brood embryos in a pouch; developed juveniles are released. This reproductive pattern is scientifically described for the genus. Aquarium observations report occasional births in Tylomelania, but reliable species-specific intervals or brood sizes for T. perfecta were not established. Do not expect a fixed output. A single snail cannot reproduce alone, and sexing is difficult for aquarium keepers.
Keeping with fish
No controlled cohabitation trials were found for Tylomelania perfecta with named fish species. Avoid fish that eat snails, damage their tentacles, outcompete them for food or dislodge them from resting places. Matching temperature alone does not prove a safe pairing. A peaceful fish should only be considered when water chemistry, adult size, feeding access and bottom space suit both species. When uncertain, a lightly stocked species-focused aquarium is the cautious choice.
Keeping with other invertebrates
Other heavy biofilm grazers may compete for natural growth; this matters with other nerite snails. Specialist Tylomelania guidance warns against large populations of food competitors. This is not evidence of aggression or direct harm between snails, but it is a reason to monitor stocking, supplemental feeding and body condition. Avoid mixing Tylomelania species when maintaining a true-breeding line matters: crosses within the genus have been reported in trade and aquaria. Controlled studies of exact pairs are often absent.
Exoskeleton, shell and minerals
A snail does not moult like a shrimp. Tylomelania grows from the shell opening; a damaged shell or withdrawn animal is not a normal moult. A porous, crumbling or heavily eroded shell can indicate unsuitable water chemistry or prolonged food and mineral shortages, but appearance alone cannot diagnose the cause. Check stability, food access and possible injury. Do not raise hardness or pH abruptly without considering all aquarium inhabitants.
Possible problems
Key risks include insufficient growth in a young or spotless aquarium, food competition, water kept too cool and uncertain trade identification. Watch for prolonged inactivity, failure to respond to food or shell deterioration; first check measurable water values and food access. A shell alone may not make a dead animal immediately obvious. For wild-caught stock, ask about origin and transport history. Never release aquarium animals, water or plants into ponds, drains or natural lakes.
Keeping with other species
Dusky nerite snail
Not recommendedDiscouraged as a routine pairing: both species graze on surface growth and may compete for limited natural food. Tylomelania literature warns against keeping large populations of food competitors. Check their water and feeding needs separately; this is a cautious source-based assessment, not a pairing trial.
View species profile →Suitable plants
Dwarf Anubias
Conditional: attach Anubias nana to wood or stone. Genus-level literature reports that some hard-substrate Tylomelania may nibble intact aquatic plants; T. perfecta has not been tested with Anubias in a controlled trial. Monitor leaves and retain alternative grazing surfaces.
- Light
- Low, Moderate
- CO₂
- CO₂ injection not needed
Sources & review
This care guide draws on several specialist sources and was last checked on .
View the sources
- Practical Fishkeeping — Chris Lukhaup — firsthand Sulawesi observations
- MolluscaBase / World Register of Marine Species — Tylomelania perfecta (Mousson, 1849), AphiaID 1062867
- MolluscaBase / WoRMS REST service — WoRMS AphiaRecord 1062867
- von Rintelen & Glaubrecht, Biological Journal of the Linnean Society 85 (2005):513–542 — Anatomy of an adaptive radiation: a unique reproductive strategy in Tylomelania
- von Rintelen et al., PLOS ONE (2014) — A Snail Perspective on the Biogeography of Sulawesi, Indonesia
- Aquaportail — Tylomelania perfecta — aquarium profile
- Interaquaristik — Donnerkeilschnecke, Tylomelania perfecta
- Wikimedia Commons — Category:Tylomelania perfecta