
Pearlscale Texas Cichlid (Herichthys carpintis)
22–28°C · pH 7–8.5 · 350L

Heros severum (listed as Convict Fish): a ~20cm mid-water South American cichlid for 250L+ tanks. Moderate care, broad tankmate options.
Adult size is the maximum length this species reaches at full maturity (scientific sources). The livestock you receive will be younger and smaller — pick a size variant above for the actual shipping size. Photos are AI-enhanced, so the animal may show subtle colour or marking differences.
Heros severum
Convict Fish bond and breed in male/female pairs — buying a pair gives them the social structure they need.
Heros severum (listed as Convict Fish): a ~20cm mid-water South American cichlid for 250L+ tanks. Moderate care, broad tankmate options.
Adult size is the maximum length this species reaches at full maturity (scientific sources). The livestock you receive will be younger and smaller — pick a size variant above for the actual shipping size. Photos are AI-enhanced, so the animal may show subtle colour or marking differences.

Cichlids are one of the most diverse fish families in the hobby. From tiny apistogrammas to massive oscars, this guide covers the basics of keeping them well.
Maintain these water conditions for optimal health and vibrant colors
Heros severum has anchored spacious South American communities for generations of fishkeepers, and this listing — carried under the trade name Convict Fish — is the standard form of that dependable species. Growing to about 20 cm and holding the middle of the tank, it offers the presence of a big cichlid with far less of the attitude that usually comes attached.
The numbers behind it are reassuring. Care is moderate; the recorded range runs 24–30 °C, pH 6.0–7.5 and a soft-to-medium 2–15 dGH; and an omnivorous diet means it takes a broad menu without fuss. Plan for 250 litres as a minimum and a ten-year relationship — these are long-haul fish, and a settled adult becomes a fixture of the room rather than just the tank. Day to day it is semi-aggressive at most, becoming genuinely territorial mainly when breeding.
Note the breadth of that recorded temperature range before you file this away as just another big cichlid. Spanning 24–30 °C, it overlaps with an unusually wide spread of heated systems, and the matching pH window of 6.0–7.5 covers everything from softly acidic through to neutral water. Few cichlids of this size hand a UK fishkeeper that much room to work with, which goes a long way towards explaining why severums keep their place on stock lists decade after decade.
Its compatibility list is one of the broadest among cichlids this size: other medium peaceful-to-semi-aggressive South American cichlids, large peaceful characins, Corydoras catfish, plecos, robust loaches and large peaceful barbs all qualify. What to leave out: fish small enough to be eaten, fin-nippers, very aggressive cichlids, tiny shrimp, and delicate slow-moving species.
One severum makes a superb community centrepiece, so settle the tankmate list before it arrives rather than after. Orders go out UK-wide with a licensed live-animal courier and are protected by our live arrival guarantee. That breadth of compatible company gives you real design freedom across the lower and middle levels of the aquarium.

22–28°C · pH 7–8.5 · 350L

22–28°C · pH 7–8 · 450L

23–30°C · pH 6.5–8 · 200L


24–28°C · pH 4.5–6.5 · 60L

24–30°C · pH 6.5–8 · 250L

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23–27°C · pH 7.4–8.4 · 500L

20–27°C · pH 6–7 · 54L

23–27°C · pH 7.4–8.4 · 150L

24–28°C · pH 6.5–7.8 · 300L

20–24°C · pH 7–8 · 45L

24–28°C · pH 6.5–7.5 · 2000L

24–28°C · pH 7.5–8.5 · 200L

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18–25°C · pH 6–8 · 100L

24–28°C · pH 7–8 · 120L

18–28°C · pH 6.5–8 · 20L

24–27°C · pH 7.5–8.8 · 150L

22–26°C · pH 6–7.5 · 60L

24–28°C · pH 7.5–8.5 · 40L

24–28°C · pH 7.5–8.5 · 500L