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No federal permit to keepBlue streak hap
Labidochromis caeruleus
Fishes › Cichlids (Cichliformes) › Cichlidae (Cichlids)
Labidochromis caeruleus is a species of cichlid endemic to the central western coastal region of Lake Malawi in East Africa.
Care at a glance
Species-specific values
Values researched for this exact species. Where they differ from the group guide below, follow these. Air, surface and water temperatures are listed separately, and each source is kept as published rather than averaged.
| Water temperature | 75–82 °F (24–28 °C) Maintenance recommendations from this source; do not replace with a multisource average. | 255 |
| Water pH | 7.7–8.6 Maintenance recommendations from this source; do not replace with a multisource average. | 255 |
| Water general hardness | 10–25 dGH Maintenance recommendations from this source; do not replace with a multisource average. | 255 |
| Adult standard length | 100 mm Maximum standard length reported by source; excludes caudal fin, not total body length. | 255 |
| Minimum tank base | length: 90 cm; width: 45 cm Minimum aquarium base recommended by this source, not a tank-volume specification. | 255 |
| Diet | Vegetable foods with live or frozen foods; this source recommends a large vegetable component. Species recommendation; avoid the group guide blanket ban on animal protein. | 255 |
Species-specific aquarium care
- Tank: At least 24 in long and 12 in front to back for one adult (adults commonly reach about 3.2 in / 8.1 cm).
- Water: Freshwater.
- Temperature: 73–79°F (range recorded for this species).
- Layout: Uses both the bottom and open water: give open swimming space plus cover near the substrate.
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 35 × 18 in (roughly 41 US gallons); space needed is rated “large tank”.
- Water: hard, alkaline water, 75–82 °F, pH 7.7–8.6, 10–25 dGH.
- Behaviour: temperament peaceful.
- Difficulty: Moderate (Seriously Fish rating).
Short excerpts from the species profile:
- Setup: “Much of the aquarium should contain piles of rocks arranged to form caves with small areas of open water between.”
- Tankmates: “A relatively peaceful species ideal for many hard water communities.”
From the Seriously Fish profile for this species, which has the full habitat, maintenance, diet, behaviour and breeding write-up 167
Lake Malawi mbuna
Applies to most species in this group. Habitat: Rocky shores 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) and lots of stacked rock with caves; a long tank (often 4 ft+).
- Keep in crowded groups of one male to several females per species, to spread aggression.
Climate & lighting
| Water | 76–82°F |
Diet
- Choose diet by mbuna species. The L. caeruleus profile offers vegetable foods alongside live or frozen foods; do not impose a universal ban on animal protein.
- Feed small amounts once or twice a day.
Social life
- Territorial; overstock mbuna-only tanks rather than mixing with peaceful fish.
Health watch
- Monitor water quality, feeding and aggression. Do not present dietary protein alone as a confirmed diagnosis or universal cause of abdominal swelling.
Understanding the animal
About this animal
About this animal
It has many common names, such as lemon yellow lab, the blue streak hap, the electric yellow or yellow prince, depending on the colour morph. The naturally occurring yellow-coloured variant from Lion's Cove is one of the most popular cichlids amongst aquarium hobbyists.
Quoted from the Wikipedia article “Labidochromis caeruleus” (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. Uses both the bottom and open water. Aquarium keeping: many females for one male; minimum aquarium size 80 cm. |
| Water it lives in | Freshwater, 73–79 °F (23–26 °C). |
| Climate | Tropical climate. |
| Behavior to plan for | Breeding: external brooders. |
What this means for care
- Keep water within its wild range, 73–79 °F.
Native climate (measured)
Native climate (measured)
| Warm-season highs | about 85°F (up to 87°F in the hottest sampled areas) |
| Cool-season lows | about 59°F (down to 55°F in the coldest sampled areas) |
| Average temperature | 70–74°F across sampled records |
| Relative humidity | 70–73% on average (driest month about 60%) |
| Rainfall | about 1328 mm a year, with strong wet and dry seasons |
Measured at 5 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 | Labidochromis caeruleus is a species of cichlid endemic to the central western coastal region of Lake Malawi in East Africa. It has many common names, such as lemon yellow lab, the blue streak hap, the electric yellow or yellow prince, depending on the colour morph. The naturally occurring yellow-coloured variant from Lion's Cove is one of the most popular cichlids amongst aquarium hobbyists. Electric yellows inhabit water with a pH between 7.8 and 8.9 and an ideal temperature range of 23–26 °C (73.4–78.8 °F). — 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 | This species, like the Astatotilapia burtoni, is a maternal mouthbrooder, meaning the eggs are carried, hatch, and develop in the mother's mouth (buccal cavity), for about three weeks. These fish are ovophiles and the male will excavate a pit in the sand within his territory, in which the female lays the eggs; the female then takes these eggs into her mouth for fertilization. — Wikipedia (community-edited) |
| Appearance and size | FishBase lists a maximum length of 8.1 cm, although other sources state a larger size of 10 to 15 cm. — Wikipedia (community-edited) |
| Biology | Aquarium keeping: many females for one male; minimum aquarium size 80 cm. — 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 standard length (snout to the base of the tail, not counting the tail fin). Fish in home aquariums often stay smaller than wild records.
Water temperature
Range the species tolerates in nature; aim for the middle.
pH
Water hardness
Minimum tank footprint
Seriously Fish recommends a tank base of at least 35 × 18 in (about 41 US gallons).
Veterinary & husbandry research
Veterinary & husbandry research
- Detection of mycobacteria in aquarium fish in Slovenia by culture and molecular methods Pate M et al., Diseases of aquatic organisms 2005
Peer-reviewed papers that mention this species alongside captivity, zoos, veterinary care or aquaculture. Some cover several species or mention it only in passing, so check the abstract. 170
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 — Labidochromis caeruleus 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.
- PubMed (U.S. National Library of Medicine) Peer-reviewed researchIndex of peer-reviewed veterinary, zoo and husbandry research.
- iNaturalist (captive observations) Community referenceCommunity observation platform run by the California Academy of Sciences and National Geographic; observations marked captive show animals living in homes, zoos and aquariums.
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