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No federal permit to keepSnail-crusher Hap
Trematocranus placodon
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Trematocranus placodon is a species of cichlid fish endemic to Lake Malawi, Lake Malombe and the upper reaches of the Shire River in Africa.
Care at a glance
Species-specific aquarium care
- Tank: At least 42 in long and 21 in front to back for one adult (adults commonly reach about 9.8 in / 25 cm).
- Water: Freshwater.
- Temperature: 75–79°F (range recorded for this species).
- pH: 7–8.5.
- Hardness: 0–25 dGH.
- Layout: Lives on or near the bottom: floor space and hiding places matter more than height.
- Diet: A predator: feed meaty foods sized to its mouth (frozen fish, shrimp, worms); it will eat tankmates that fit in its mouth. FishBase classes it as a carnivore.
Calculated from this species' own FishBase record: tank size from its typical adult length and swimming zone, water values from its recorded ranges. The group guide below fills in general care.
Care guide
Species care notes
- Tank: a base of at least 59 × 15 in (roughly 68 US gallons); space needed is rated “very large tank”.
- Water: hard, alkaline water, 75–82 °F, pH 7.6–8.8, 10–25 dGH.
- Difficulty: Moderate (Seriously Fish rating).
Short excerpts from the species profile:
- Setup: “Set up the aquarium with piles of rocks arranged to form caves, large areas of open water for swimming and preferably a sandy substrate.”
- Diet: “Will accept most foods offered, and a varied diet of live, frozen and dried foods suits this species.”
- Tankmates: “Unless the tank is very large, it is probably best in a species setup, as the fish are territorial, and males can command large territories.”
From the Seriously Fish profile for this species, which has the full habitat, maintenance, diet, behaviour and breeding write-up 167
Lake Malawi peacocks and haps
Applies to most species in this group. Habitat: Open water and sand of Lake Malawi. Individual species can differ, so compare with the species numbers above and the linked sources.
Housing & setup
- Hard, alkaline water (pH 7.8–8.6), a long tank (5 ft+ for larger haps) with open sand and some rock.
- Generally less aggressive than mbuna; males color up best with several females.
Climate & lighting
| Water | 76–82°F |
Diet
- For Aulonocara stuartgranti, use small prepared foods with some vegetable content and varied small live/frozen invertebrates. Match other haps to their own feeding ecology.
Health watch
- Do not diagnose bloat from a label such as “mbuna-style food”; Aulonocara stuartgranti diets can include vegetable foods. Match food and tankmates to the species.
Understanding the animal
About this animal
About this animal
It is mainly a shallow-water species that prefers to occupy areas with patches of Vallisneria, but it can occur as deep as 31 m (102 ft). It can reach a total length of up to 25 cm (9.8 in).
Quoted from the Wikipedia article “Trematocranus placodon” (CC BY-SA 4.0) 174
In the wild
In the wild
From this species’ own FishBase record (habitat, bottom type, water and breeding data), not its family. Good care copies these conditions.1
| Where it lives | Lives in freshwater. Stays near the bottom. |
| Water it lives in | Freshwater, 75–79 °F (24–26 °C), pH 7–8.5, hardness 25 dH. |
| Climate | Tropical climate. |
| Wild diet | Hunting macrofauna (predator). |
| Behavior to plan for | Breeding: external brooders. |
What this means for care
- Keep water within its wild range, 75–79 °F.
Native climate (measured)
Native climate (measured)
| Warm-season highs | about 87°F (up to 90°F in the hottest sampled areas) |
| Cool-season lows | about 59°F (down to 50°F in the coldest sampled areas) |
| Average temperature | 67–76°F across sampled records |
| Relative humidity | 67–70% on average (driest month about 55%) |
| Rainfall | about 1138 mm a year, with strong wet and dry seasons |
Measured at 25 wild occurrence records sampled against WorldClim 2.1 climate data (1970–2000 averages). Air conditions in the range are ecological context, not enclosure settings: microhabitats such as burrows, leaf litter or basking rocks can be cooler, warmer or more humid.
From the sources
From the sources
Quoted from the matching sections of reputable sources for this exact species. Specialist databases are used first; Wikipedia (community-edited, CC BY-SA 4.0) only fills gaps. Other sources are short credited quotes.
| Overview | Trematocranus placodon is a species of cichlid fish endemic to Lake Malawi, Lake Malombe and the upper reaches of the Shire River in Africa. It is mainly a shallow-water species that prefers to occupy areas with patches of Vallisneria, but it can occur as deep as 31 m. It can reach a total length of up to 25 cm. It feeds mainly on aquatic snails and has a preference for Bulinus nyassanus, making this cichlid beneficial to humans as that snail is an intermediate host of the parasite bilharzia (schistosomiasis). — Wikipedia (community-edited) |
| Where it lives | Home ranges Population dynamics Growth parameters Max. ages / sizes Length-weight rel. Length-frequencies Mass conversion Recruitment Abundance Life cycle Reproduction Maturity Maturity/Gills rel. — FishBase |
| Reproduction | The female can carry over 100 young in her mouth. — FishBase |
| Biology | Shallow-water species (, 55954 ), especially in swards of Vallisneria. Feeds mainly on gastropods, including Gabiella stanleyi, which is commonly found on the leaves of Vallisneria. — FishBase |
Data and studies
The numbers
The numbers
Each bar is what one source reports. Where several sources weigh in, the dashed gold band marks their average.
Adult length
Maximum recorded length. Measured as total length. Fish in home aquariums often stay smaller than wild records.
Water temperature
Range the species tolerates in nature; aim for the middle.
Water hardness
Minimum tank footprint
Seriously Fish recommends a tank base of at least 59 × 15 in (about 68 US gallons).
Sources for this sheet
- FishBase (Froese & Pauly, eds.), version 24.07 Peer-reviewed researchThe global scientific database on fishes, maintained by a consortium of research institutions; every value is referenced.
- Seriously Fish species profiles Experienced keeper or breederLong-running aquarium reference written and peer-checked by experienced fishkeepers and ichthyologists; each profile covers habitat, tank size, water, diet, behaviour and breeding.
- Merck Veterinary Manual: Management of aquarium fish Zoo, university or veterinaryThe Merck Veterinary Manual: a standard veterinary reference written and reviewed by veterinary specialists.
- Merck Veterinary Manual: Types and features of aquatic systems Zoo, university or veterinaryThe Merck Veterinary Manual: a standard veterinary reference written and reviewed by veterinary specialists.
- Merck Veterinary Manual: Nutritional diseases of fish Zoo, university or veterinaryThe Merck Veterinary Manual: a standard veterinary reference written and reviewed by veterinary specialists.
- Seriously Fish — Aulonocara stuartgranti Zoo, university or veterinaryAdded in the 2026 source-checked care-guide review.
- Wikipedia (species article) Community referenceFree encyclopedia; useful overviews with their own citations. Intro text is quoted under CC BY-SA 4.0.
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