The Masked Julie is the smallest of the Julies, so easy to house in tight quarters!

The Masked Julie Julidochromis transcriptus is an attractive little cichlid from the northwest shores of Lake Tanganyika, Africa. It is the smallest of its genus with the female growing only to only about 2 3/4 Inches (7 cm) and the male is a little smaller. This is barely half the size of many of its cousins. A small, dimly lit aquarium works great for this fish.

This cichlid has a cylindrical-shaped body with a slightly larger upper lip used to search for food. Its coloring is a silver/white with irregular horizontal and vertical brown bars. There are several slightly different color pattern variations of the Masked Julie, and all are very attractive. These patterns vary depending upon the location in Lake Tanganyika where each specimen is collected. There are differences in color or bars and sometimes they can be almost blotches. The dark colors always extend into the dorsal fin but the belly is always white. Another common name it is known by is the Black and White Julie.

Some varieties of the Masked Julie can have a very similar color patterning to their close relative the Marlier’s Julie. They are similar in their care requirements too, but they can be distinguished in a couple of ways. A Masked Julie with a checkered patterning will have only two rows of white spots, while the Marlier’s Julie has three or more. A couple other differences are the Marlier’s Julie is almost twice as large and the male has a lump-like swelling on the neck, which is absent from males of this species.

This cichlid is somewhat shy. It will stay in the rocks more towards the back of the aquarium, darting out to retrieve food. They do well in a community cichlid tank and can be kept singly, in a pair, or in a group of several pairs if the aquarium is large enough. They can also be kept with other Tanganyika cichlids that are similar in size. A 20-gallon tank with lots of rockwork is perfect for keeping a pair. In a community it is important to keep conspecific varieties and similar species separate to help prevent hybrid strains.

They are moderatelyeasy to care for as long as small weekly water changes are done to keep the water at optimal levels. With their small size and hardy nature, they make a great fish for the beginning cichlid keeper. Provide them with a sandy or fine gravel substrate along with lots of rock formations. They stay very close to rock structures, so the more rocks there are, the more comfortable they will be. Plants can also be included as they will not bother them. This fish will breed in captivity and the plants will provide cover for the newly hatch fry.

Scientific Classification


Masked Julie – Quick Aquarium Care

Aquarist Experience Level:Beginner
Aquarium Hardiness:Moderately hardy
Minimum Tank Size:20 gal (76 L)
Size of fish – inches2.8 inches (7.01 cm)
Temperature:73.0 to 80.0° F (22.8 to 26.7&deg C)

Habitat: Distribution / Background

The Masked Julie Julidochromis transcriptus was described by Matthes in 1959. They are found in the north western part of Lake Tanganyika in Africa, between Luhanga and Makabola. This species is listed on the IUCN Red List as Lease Concern (LC). Although it is endemic to Lake Malawi, it is widespread in the northern part of the lake and has no recognized threats at present.

Another common name this fish is known by is the Black and White Julie. There are a number of geographical variants. These color morphs are often named for the area where they come from. These include the popular Julidochromis transcriptus “Gombe” as well as”Bemba”, “Korosha”, “Kissi”, “Kolombo”, “Luhanga”, “Kisonso”, “Kapampa”, “Katoto”, and “‘Kalemie” to name a few.

The Julidochromis genus is a small group of cichlids in Lake Tanganyika with about 5 described species and a number of variants or possible subspecies. They are commonly known as “Julies” in the aquarium hobby. They are small to mid-sized cichlids with elongated torpedo shaped bodies. Their coloration is a yellow or whitish background with either black horizontal stripes or a checkerboard pattern. They inhabit rocky areas and mostly form monogamous pairs, though pairs can be broken with the smaller fish being driven off or even killed. These fish are secretive bi-parental substrate spawners, mostly spawning in caves or crevices in the rocks. They are very territorial, but as parents, after a week or two they generally will neither protect nor attack their young, but small fry still gain protection by residing within their parents territory.

This genus is one of the smallest groups in the tribe Lamprologini. The Lamprologini tribe contains seven genera and nearly 100 species of African Cichlids, most of which are found in Lake Tanganyika. The Lamprologini cichlids are highly variable and are found in all kinds of habitats. They are found both at the surface and in very deep waters, but all species are substrate spawners. Like other genus in the tribe, the julidochromis will mate with females of other Lamprologini.

These cichlids are found along the rocky coastlines at depths between 15 – 80 feet (5.6 – 24 m). They are found singly and are territorial. They feed on zooplankton and benthic invertebrates found in the algae growth in the wild.

  • Scientific Name: Julidochromis transcriptus
  • Social Grouping: Solitary – They are a solitary species, pairing up when spawning.
  • IUCN Red List: LC – Least Concern


The Masked Julie has a torpedo shaped body with a continuous dorsal fin and a fan shaped caudal fin. It has a slightly larger upper lip that is used for searching for organisms in the sand and algae on the rocks. This Julie cichlid is the smallest of its genus. The female grows to about 2 3/4 inches (7 cm), with the male being a little smaller. This species can have a lifespan of 5 – 8 years with proper care.

.Depending on location, there are differences in color or bars. The most common variety has a silver/white base color. There are irregular horizontal and vertical brown bars, or almost blotches, and they extend into the dorsal fin. The belly has no bars and is silver/white. The face has one horizontal bar that runs through the eye, a “U” shaped bar on the forehead, and a bar that splits the “U” in half. They have clearish fins with all fins having light blue margins.

There are slight differences in the Masked Julie depending on the region where they are found. The most sought after variant is called Julidochromis transcriptus “Gombe”, or Julidochromis transcriptus “Gombi”, which originates from Gombe. Its body has a light gold cast and seven unbroken vertical brown bars, running from the top of the dorsal fin all the way down into the belly. The bars on the face are thicker as well but there are no bars below the eye, only one that goes through the eye.The fins appear darker due to the contrast of the brown and light gold coloring. There is a brown dot at the base of the tail fin.

A few of the other variants include the Julidochromis transcriptus “Bemba”, Julidochromis transcriptus “Kissi Bemba ” or Julidochromis transcriptus “Kissi “, Julidochromis transcriptus “Kolombo”, and others such as “Korosha”, “Luhanga”, “Kisonso”, “Kapamp”, “Katoto”, and “Kalemie”.

All cichlids share a common feature that some saltwater fish such as wrasses and parrotfish have and that is a well-developed pharyngeal set of teeth that are in the throat, along with their regular teeth. Cichlids have spiny rays in the back parts of the anal, dorsal, pectoral, and pelvic fins to help discourage predators. The front part of these fins are soft and perfect for precise positions and effortless movements in the water as opposed to fast swimming.

Cichlids have one nostril on each side while other fish have 2 sets. To sense “smells” in the water, they suck water in and expel the water right back out after being “sampled” for a short or longer time, depending on how much the cichlid needs to “smell” the water. This feature is shared by saltwater damselfish and cichlids are thought to be closely related.

  • Size of fish – inches: 2.8 inches (7.01 cm) – The female grows to a length of almost 3″ (7 cm), with the male being a little smaller.
  • Lifespan: 5 years – They have a lifespan of 5 – 8 years with proper care.

Fish Keeping Difficulty

This fish is a great choice for both the beginner and advance aquarist. It is moderately easy to care for as long it has the proper sized aquarium and the right tank mates. They are fairly peaceful, making good inhabitants for the community cichlid tank. It will eat a wide variety of aquarium foods and will readily breed. The aquarium does need regular water changes.

  • Aquarium Hardiness: Moderately hardy
  • Aquarist Experience Level: Beginner

Foods and Feeding

The Masked Julie is an omnivore. In the wild they feed on zooplankton and benthic invertebrates found in the algae growth. In the aquarium to keep a good balance give them a high quality flake food or small pellet everyday. Regularly supplement these with Cyclops, water fleas, and brine shrimp, or other special foods for Lake Tanganyika cichlids. Mysis may be fed sparingly but it is very high in fat, which is not good for this fish.

Feed 2 to 5 small pinches of food a day in smaller amounts instead of a large quantity once a day. This will help to keep the best water quality. All fish also benefit from vitamins and supplements added to their foods.

  • Diet Type: Omnivore
  • Flake Food: Yes
  • Tablet / Pellet: Yes
  • Live foods (fishes, shrimps, worms): Some of Diet
  • Vegetable Food: Some of Diet
  • Meaty Food: Most of Diet
  • Feeding Frequency: Daily – Offer several small feedings a day rather than a single large feeding for better water quality over time.

Aquarium Care

Do normal water changes of 10% to 15% a week, or more frequent changes depending on the nitrite/ammonia levels and stocking numbers. The Lake Tanganyika cichlids cannot handle large water changes very well unless the new water water chemistry closely matches the water they are in. If a large water change is needed, changing 15% every couple of days should bring water back to normal. This inability to tolerate large water changes is due to Lake Tanganyika being very deep and the water tends to stay stable.

  • Water Changes: Weekly – Water changes of 10-15% weekly are suggested, only do more if the water parameters are off. Be cautious of doing more frequent changes as these fish are very sensitive to new water.

Aquarium Setup

The Masked Julie is active and will swim mostly in the bottom areas of the aquarium. A minimum 20 gallon tank for a pair is suggested. Provide 60 gallons or more for a community type tank. They do fine in either freshwater or brackish freshwater but need good water movement along with very strong and efficient filtration. Lake Tanganyika is a very oxygen rich lake so bubblers need to be going day and night, even if there are plants. Regularly check nitrates and ph, nitrates should be no more than 25 ppm and a pH less than 7 is not tolerated. In addition keep an eye on total hardness and carbonate hardness. Avoid overfeeding and overstocking.

Lake Tanganyika is the second to largest lake in the world, thus contributing to a low fluctuation in temperature and pH. All Tanganyika cichlids need stable temperatures kept within acceptable limits and lots of oxygen to survive. Temperatures under 72° F and over 86° F for too long is not tolerated by many of these fish. When treating for ich, a few days at 86° F is acceptable. The lake is also consistently alkaline with a pH of around 9, and very hard at about 12 – 14° dGH. In the aquarium most Tanganyika cichlids are fairly adaptable as long as conditions are close to these ideal ranges. Most important is that their water chemistry doesn’t change much over time. The water needs to be well buffered and maintained with small, regular water changes.

Salt is sometimes used as a buffering agent to increase the water’s carbonate hardness. An alternative buffering approach is to use a chemical filtration method, where the water passes through layers of crushed coral or coral sand.  Interestingly, Tanganyikan cichlids also need iodine for the thyroid to function properly to regulate growth and development, and which can be achieved by adding iodized table salt to the water. Although rift lake cichlids need hard alkaline water they are not found in brackish waters. This cichlid has some salt tolerance so can be kept in slightly brackish water conditions. However it not suited to a full brackish water tank. It can tolerate a salinity that is about 10% of a normal saltwater tank, a specific gravity of less than 1.0002.

A sandy or small gravel substrate will make them feel comfortable. Provide lots of porous rocks and/or whole or pieces of clay pots forming caves and crevices.They stay very close to rock structures, so the more rocks there are, the more comfortable they will be. Plants can also be included as they will not bother them, and will provide cover for the newly hatch fry.  Subdued lighting is also preferred.

  • Minimum Tank Size: 20 gal (76 L) – A minimum of 20 gallons is suggested for a pair, with 60 gallons or more if keeping a community type tank.
  • Suitable for Nano Tank: Sometimes – A 20 gallon Nano tank can accomodate a pair, but more fish will require a much larger aquarium.
  • Substrate Type: Sand – Sand or a very fine gravel substrate should be used.
  • Lighting Needs: Low – subdued lighting
  • Temperature: 73.0 to 80.0° F (22.8 to 26.7&deg C)
  • Range ph: 8.5-9.2 – They will tolerate a slow change to just above neutral.
  • Hardness Range: 8 – 14 dGH
  • Brackish: Sometimes – Salt is not found in their natural environment, but they do have a slight tolerance, keep levels below 10% – a specific gravity of less than 1.0002.
  • Water Movement: Moderate
  • Water Region: Bottom – These fish will swim in the bottom areas of the aquarium.

Social Behaviors

The Masked Julie does well in a community cichlid tank and can be kept singly, in a pair, or in a group of several pairs if the tank is large enough. This fish is a community cichlid that can be kept with other Tanganyika cichlids that are similar in size. They are peaceful toward those of the same species, but will not tolerate their own offspring. They will tolerate those of a different genus.

They will breed in the main tank if there are enough crevices. You may want to remove a confirmed pair to a 20 gallon tank to breed however, as they will aggressively protect their brood from any intruders. Once the fry are about an inch in length the parents will chase them away. Do not house them with other Julies to avoid cross breeding. Also do not house them with plecostomus if breeding, as these bottom dwelling fish will eat the fry at night.

  • Temperament: Semi-aggressive
  • Compatible with:
    • Same species – conspecifics: Yes – They can in a pair or in a group of several pairs if the tank is large enough.
    • Peaceful fish (): Threat
    • Semi-Aggressive (): Safe – They can be kept in a community with other similar sized Tanganyika cichlids.
    • Aggressive (): Threat
    • Large Semi-Aggressive (): Threat
    • Large Aggressive, Predatory (): Threat
    • Threat
    • Shrimps, Crabs, Snails: Threat – is aggressive
    • Plants: Safe

Sexual differences

The Masked Julie are hard to sex as juveniles but once they pair off, a male and female pair becomes clear. Males are said to be smaller than the females.

Breeding / Reproduction

The Masked Julies are egg layers that will form monogamous pairs and a nuclear family. They are sheltered substrate spawner and prefer spawning in caves. This fish has been bred in captivity but young couples need practice to become successful parents. Do not be surprised if they eat their first clutch or two.

They are shelter spawners so provide them with caves made from rocks and/or clay planting pots and/or pieces of slate, as they adhere their eggs to the “roof” of their cave. Buy 6 to 10 juveniles and put all of them in the tank you plan to use for breeding. Do it this way because if you move a newly established pair to a breeding tank, you may meet with failure. Once you have a pair the male will start to mark off territories. Remove the extras after a pair splits off. It is best not to rearrange the rocks or move any decorations around in the aquarium once they form territories. This can stress them out and will very likely break the bond a male and female have made. The reason for this is that part of their bond is connected to the “territory” more than to each other.

The male will entice the female into a cave and their spawn will consists of a few eggs being laid each day for several days. Thus the whole spawn will have fry of different sizes when they are all hatched. Make sure there are a lot of crevices for the young to hide in and do not use plecostomus in the tank, as they will eat the young during the night.

The parents are dedicated to their young, and will take turns guarding the fry while the other leaves to eat. The parents will allow the fry to stay in the area until they are 1″ long, even when new batches are hatched since they will help guard their siblings. After that the parents will chase them away.

Although the parents do well guarding their fry, they have a limited survival rate. For a higher success rate, siphon out most of the fry when they are born and put them in a separate 10 gallon tank, leaving a few in the tank for the parents to care for. Feed the fry baby brine shrimp. The fry are slow growers. It takes almost 2 months for them reach 2 cm in size. See the description of breeding monogamous cichlids in: Breeding Freshwater Fish: Cichlids.

  • Ease of Breeding: Easy

Fish Diseases

The Masked Julie is susceptible to typical fish ailments, especially if water is stale and of poor quality and oxygenation. An ounce of prevention is worth a pound of cure. Water changes, not overfeeding or overcrowding, and observation along with feeding your fish the proper foods (thawing frozen food and adding vitamins) will keep them in optimum health. For freshwater an optional practice is to add 1 heaping teaspoon of salt per 11 gallons of water. This is considered to be a simple and natural remedy for wounds, minor fungal infections and film over the eyes of fish in transit. Using a marine salt (used for salt water fish) will add some trace elements.

One common problem is Ich. It can be treated with the elevation of the tank temperature to 86° F (30° C) for 3 days. If that does not cure the Ich, then the fish needs to be treated with copper (remove any water conditioners). Several copper based fish medications are available for Ich. Copper use must be kept within the proper levels, so be sure to follow the manufacturers suggestions. A copper test also can be used to keep the proper levels. You can also combine increasing the temperature with an Ich medication treatment.

As with most fish they are susceptible to skin flukes and other parasitic infestations (protozoa, worms, etc.), fungal infections, and bacterial infections. It is recommended to read up on the common tank diseases. Knowing the signs and catching and treating them early makes a huge difference. For information about freshwater fish diseases and illnesses, see Aquarium Fish Diseases and Treatments.


The Masked Julie is available both online and sometimes in fish stores and is moderately priced, though prices vary depending on size and variety. Purchase from a reputable dealer, due to hybridization it takes a trained eye to choose the correct color strain that has not been crossed.



 Julidochromis transcriptus (Image Credit: Przemysław Malkowski, Wikimedia Commons CC BY-SA 4.0 International)