Thorichthys Pasionis, also known as the blackgullet cichlid, is one of the mystery cichlids from Central and South America.

It is relatively rare, difficult to find, and can be expensive to purchase. Owners praise them for their classic cichlid beauty, attractive coloring, and even tempers.

How much do you know about the black gullet cichlid? If you are looking to build your cichlid experience or get into the species with a smaller fish, we have you covered. Read on for everything you need to know about the care, maintenance, and breeding of Thorichthys Pasionis.


Size: 4-6 inches (00-00 cm) in captivity,
Tank: 100 gallons for a small school. 200 gallons with a few tank mates
Strata: All over but tend to stay in the middle or bottom of the tank.
PH: 6.5-8
Hardness: Soft to medium. dH range: 5-12
Temperature: 75 F-85 F (00 – 30 C)
Order: Perciformes
Family: Cichlidae
Sub-Family : Cichlinae
Genus: Thorichthys
Species: T. Pasionis

Origin and Appearance

Thorichthys Pasionis is a smaller variety of cichlid found in a wide region of Central America. Its range covers parts of coastal Mexico, Guatemala, the Yucatan peninsula, and Belize.

It is a fish that prefers shallow, muddy bottoms in warm, slow-moving water. What is unique about the blackgullet cichlid is that when you find this species, you also find its cichlid relative Thorichthys meeki, also known as the firemouth or meeki cichlid. They are so common together that the blackgullet is often called the yellow meeki.

It is called the blackgullet cichlid because of the black margin found around the outsides of their gills.

In appearance, the blackgullet cichlid has a universally recognizable cichlid oval or disc-shaped body. It has a row of spines embedded in its dorsal fin that extends almost to the tail. The front spines, in particular, can deliver nasty punctures, so care should be taken if you handle them.

Blackgullet cichlids have a beautiful yellow body color with an iridescent blue sheen and blue highlights on their fins and around the black markings on their sides. Most adult fish have a large black blotch on the upper back near their tail. Females will have sporadic black dots and horizontal bars along their lateral lines.

Juvenile fish have a bland, muted coloring that helps them blend into the background. At around three inches in length, the fish begin to gain their adult colors and are able to be differentiated as male or female.

The average thorichthys pasionis size when well cared for is about 5 inches. In the wild, Male blackgullet cichlids are larger at nearly six inches. Females will reach four inches. Their average lifespan is 8 to 10 years.

The blackgullet cichlid is one of the mild-tempered fish in the species.  When you keep them in larger tanks with a school of six to eight of their own kind, they mostly ignore other fish except when they are in breeding mode.

Blackgullet cichlids have teeth, but unlike many of the sifter varieties of cichlid, they are more like pickers, uncovering and eating small insects and marine life. They still soft their food but seem to be more selective in what they pick up than other cichlids.


The blackgullet cichlid is considered an easy species to keep. Their water temperature and quality needs are met by standard aquarium equipment.

The only real challenge to their care is water changes. If you have a larger con-species tank of 200 gallons or more, changing the water requires a lot of planning for siphoning and replacing with conditioned water.

Pump and filter systems help alleviate this chore and allow you to focus your energies on quality care.

The blackgullet cichlid is a schooling species and needs some of its own kind for companionship. Housing a small group of young fish can be done in a 55-gallon tank.

Scaling up to 100 gallons, or 200 gallons if you want to add tank mates, gives all fish room to swim about and provides enough space for some territory selection if your blackgullet cichlids try to spawn.

Match the size of your filtration and tank heater to the size of your aquarium. These cichlids like their water between 75 F and 85 F, with a preference on the warmer side. Water quality is very basic, with average pH and dH. They can tolerate some change in water quality as long as the water is kept clean. Most cichlids do well with a 10 percent to 15 percent water change weekly.

Blackgullet cichlids have a reputation for leaping through. This can be a matter of debate. The safest approach is to cover the tank and limit plants to those that will not try to grow out.

If you have a group of blackgullet cichlids in a large enough tank, they will choose a section and acquire it as their territory. This is a good trait to encourage as it keeps them happy, and they don’t bother other fish in the tank.

– Tank Decoration

Aquascaping helps keep them centered. Just as you would with larger cichlids, you can build rock and structure areas they will identify as their own.

Both sand and gravel make good choices for a substrate. Blackgullet cichlids like dim environments and will display better against dark gravel.

Assortments of large and small rocks, or flower pots on their side, will give them places to explore. If you have juvenile fish, they may be shy and will use these caves to hide.

Plants are a matter of personal choice. Both rooted and floating plants do well, but rooted plants provide more cover for them to hide in. The usual South American plant species such as guppy grass work well.

– Diet

Blackgullet cichlids are not picky eaters and will eat anything. Cichlid pellets are good choices as they sink. Foods with krill or color enhancers will help them be their most vivid.

You can give them occasional meaty treats but try to limit them to once a week as overfeeding proteins can cause illness.

– Tank Mates

If you are set up with a large tank, small groups of tank mates can get along with your blackgullet cichlids, especially if all are introduced to each other while they are juvenile fish.

Here are a few good choices:

Silver Dollars: The Silver Dollar is a species native to South America that can do well with Uaru. They are mostly peaceful, preferring the company of their species. They tend to leave other fish alone if they cannot fit them in their mouths.

Guppy: There are many varieties of guppy that make great tank mates. What they all have in common is that they are peaceful fish that are not too small and get along well with everything that will not eat them. Some of the more ornamental varieties add splashes of color to your community tank.

Avoid snails and shrimp. They tend to be food targets for cichlids and will get picked to death.


Male and female blackgullet cichlids begin to differentiate when they reach about 3 inches in length. In a comfortable tank, you may see fish pair off and start making their own territory.

To get the most success from breeding, isolate the pair into their own breeding aquarium.

The male blackgullet cichlid will make a shallow depression and encourage the female to spawn in it before depositing his milt. Both parents take turns fanning the eggs until they hatch. This takes about two days. The fry will absorb their egg sacs and should be free-swimming in about a week.

This is a good time to return the parents to their home tank.

Feed the fry infusoria or liquid food until they are big enough for baby brine shrimp. The thorichthys pasionis growth rate is quite rapid. They will reach an inch in length in about a month.

It is best to let them get to be a few inches in length before trying to home them with other species.


  • Blackgullet cichlids are a species with limited availability.
  • They average 5 inches and can live up to 10 years.
  • The species does best in large aquariums where they have room to swim; 75 gallons for a pair is a good size and 200 gallons or larger for a grouping.
  • Clean, well-balanced water is essential to their survival. Change at least 10 percent of the water weekly.
  • Use heaters to keep the temperature between 80 F and 85 F.
  • A good filtration system will help keep the water clean and the temperature of the water even throughout the aquarium.
  • Using a sand or gravel substrate, decorate with flat stones, piles stones, and flowerpots on end to give them places to explore.
  • Blackgullet cichlids are mostly peaceful and get along with other peaceful species.
  • If you plan on breeding your cichlids, set aside a breeding tank for them.
  • Breeding pairs will take turns fanning the eggs and guarding their nest.
  • The eggs usually hatch within two days.
  • Blackgullet cichlids are omnivores and not picky about what they eat. Feed them cichlid pellets that sink.
  • Give them small, meaty treats occasionally. Don’t overdo it. Too much protein can make them bloated and ill.

Blackgullet cichlids are a smaller species that give newcomers to cichlids a great experience. If you can successfully breed them, you will help bring a species that deserves more keeper attention to your part of the world.

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