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Big-mouth hap

Tyrannochromis macrostoma

Also known as Tyrant hap, Macrostoma hap

FreshwaterFish

Care at a glance

Temperature
75–82°F (24–28°C)
pH
7.6–8.6
Adult size
13.8 in (35 cm)
Minimum tank
211 gal (800 L)
Temperament
Aggressive
Social behavior
Social
Tankmates
Tankmates with caution
Swim level
Middle
Difficulty
Difficult
Breeding
Medium
Rarity
Rare
Origin
Lake Malawi, endemic
Family
Cichlidae

Overview

The big-mouth hap is a large predatory Malawi cichlid that eats smaller fish, so it can only share a tank with cichlids too big to swallow, which is a short list. Keep a single male, ideally with a few females, in a very large tank, and do not house rival males together. Its tankmates must be large, robust Malawi cichlids, never small mbuna, which are its natural prey. It cruises the open middle water above the rocks. Feed meaty foods and quality carnivore pellets, avoiding live feeder fish. This fish needs a lot of room, around 800 liters or more.

In the wild

This species is endemic to Lake Malawi, hunting over rocky shallows and taking smaller cichlids from among the stones. Give it a large tank with sturdy rockwork and, above all, open swimming space for a big, active predator. Malawi water is hard and alkaline, so keep it warm and buffered, around 24 to 28 C and pH 7.6 to 8.6, with heavy filtration.

Good to know

Tyrannochromis macrostoma is a large predatory cichlid reaching around 35 centimeters. Its names fit its habits: the genus name means tyrant and the species name macrostoma means large mouth, describing a gape built to engulf other cichlids whole. Charles Tate Regan described it in 1922. Like other Malawi haplochromines it is a maternal mouthbrooder.

Did you know

This is the fish that eats the mbuna other keepers prize: a specialised hunter of smaller Malawi cichlids, it picks prey from the rocks with a mouth wide enough to swallow an adult whole.

Common questions

What size tank does a Big-mouth hap need?

A Big-mouth hap needs at least 211 gal (800 L). It spends most of its time in the middle.

What temperature and pH do Big-mouth hap need?

Big-mouth hap are comfortable at 75–82°F (24–28°C) with a pH of 7.6–8.6.

How big do Big-mouth hap get?

An adult Big-mouth hap reaches about 13.8 in (35 cm).

Where to buy

Some links may not be the exact species or variety.

…or ask your local fish store.

Appears in

Freshwater fish · Cichlids · Advanced fish

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