Aulonocara stuartgranti
Aulonocara stuartgranti was first described by Meyer and Riehl in 1985. The genus name Aulonocara comes from the Ancient Greek words αὐλός (aulós), meaning “flute,” and κάρα (kára), meaning “head” or “face.” This name refers to the greatly enlarged sensory canal system found in the skulls of members of this genus. The species name stuartgranti honors the legendary aquarium fish exporter Stuart M. Grant (1937-2007).
Synonyms: Aulonocara hansbaenschi, Aulonocara steveni
There is significant variation in the color patterns of Aulonocara stuartgranti, which depends on geographic location. Several color morphs that were once classified as separate species, such as Aulonocara hansbaenschi and Aulonocara steveni, are now considered synonyms of Aulonocara stuartgranti. It is important to note that there are differing opinions regarding the taxonomic classification of this species, and ongoing debates exist about the exact status of some populations.
Appearance, Behavior and Life Expectancy of Aulonocara stuartgranti
General description: Aulonocara stuartgranti is a species characterized by its elongated, slightly laterally flattened body, a trait typical of most Aulonocara species. This streamlined shape aids in maneuverability within their natural habitat. Males typically have a blue head with vibrant, fluorescent coloration, while the flanks display varying color patterns influenced by geographic location and specific populations. Several color morphs exist, ranging from entirely blue to yellow, some featuring red shoulder patches. Vertical stripes are a distinguishing feature of the Aulonocara genus. The fins can also be blue or yellow, depending on the specific color morph and sex of the fish. Like all Aulonocara species, they possess relatively large eyes in proportion to their bodies. Adult males average a total length of about 12 to 15 centimeters, while females are usually slightly smaller, reaching up to around 11 centimeters. In the wild, both males and females tend to be smaller in size.
Differences between males and females: Males of the species Aulonocara stuartgranti are significantly more colorful than females. They exhibit a wide range of colors, including blue and yellow, often featuring a combination of both. In contrast, females are typically a dull gray-brown with 8 to 9 dark transverse bands along their flanks. Males are also larger than females.
Behaviorally, males display territorial tendencies, actively defending a nesting site and attracting females. Females, on the other hand, are less aggressive and do not exhibit territorial behavior. Juveniles resemble females in both color and size, gradually developing their adult coloration as they mature.
Behavior and temperament: Aulonocara stuartgranti is generally a relatively peaceful fish; however, males can become territorial, especially during the breeding season. They do not live in schools, but in small groups, often consisting of one dominant male and several females. They are not shy and are active in midwater and on the bottom, where they search for food. Their “sonar feeding” is a characteristic behavior in which they hover with their head close to the bottom and use their extensive sensory system to detect prey.
Life expectancy: The life expectancy of Aulonocara stuartgranti in the wild is not exactly known, but in an aquarium, they can live for 5 to 10 years.
Habitat of Aulonocara stuartgranti
Geographic distribution: Aulonocara stuartgranti occurs naturally in almost the entire Lake Malawi. The exact locations within the countries vary, depending on the color variant. The color variants often also include the location of origin in the name, such as Aulonocara stuartgranti “Ngara”.
Natural habitat: Aulonocara stuartgranti inhabits the transition zone between rocky and sandy areas in Lake Malawi. The documents describe the habitat as an area with loose rock outcrops and a considerable amount of open sandy bottom, often with a thick layer of sand. Aquatic plants are often absent.
Bottom/substrate: The bottom consists mainly of sand. The fish digs with its snout in the sand in search of food.
Climate: Lake Malawi has a tropical climate, characterized by stable temperatures and a lack of distinct seasons. However, it is known that the water level in Lake Malawi can fluctuate.
Diet of Aulonocara stuartgranti
Diet in the wild: The diet of Aulonocara stuartgranti in the wild consists mainly of small invertebrates that it filters from the sand. This carnivorous fish utilizes its lateral line system to detect prey, even in low light conditions. A well-known behavior of Aulonocara is “sonar feeding,” where the fish hovers close to the bottom while using its sensory system to locate prey.
Aquarium Diet: In the aquarium, Aulonocara stuartgranti will accept a variety of foods, including high-quality dry foods (such as flakes and pellets), live foods (like brine shrimp and mosquito larvae), and frozen foods (like krill and mysis). It is essential to provide a varied diet to ensure the fish receives all the necessary nutrients. Some dry foods contain a high percentage of plant material, such as spirulina, which contributes to the color and health of the fish. It is advisable to feed several small portions per day rather than one large meal, to mimic the fish’s natural foraging behavior.
Locating prey with the lateral line organ
The Aulonocara stuartgranti has an exceptionally well-developed lateral line system in its head, which it uses to locate prey in the sand, even in complete darkness. This system is a kind of sixth sense that is sensitive to vibrations and water currents. Think of it as an underwater radar.
The lateral line system consists of a network of small pores and canals in the fish’s cranial bones, particularly in the lower jaw, the preoperculum (a bone behind the gill cover), and the infraorbital bones (below the eyes). These canals contain special sensory cells called neuromasts, which detect minute movements in the water. In Aulonocara stuartgranti, these canals are greatly enlarged, unlike in many other fish. This means that there are more neuromasts, making the fish extremely sensitive to vibrations.
When a small invertebrate moves through the sand, it creates tiny water currents and vibrations. The enlarged neuromasts in the lateral line canals of the A. stuartgranti pick up these subtle signals. The fish then “hover” almost motionless above the bottom, its head close to the sand, and uses its lateral line system to determine the precise location of the prey. This behavior is called “sonar feeding.” Once the fish has located the prey, it quickly dives down to catch it.
The study by Schwalbe et al. (2012) demonstrates that the lateral line system is particularly effective for fish hunting, even in the dark. The researchers found that treating the fish with cobalt chloride—which temporarily disables the lateral line system—led to a significant decrease in their ability to locate prey, especially under low-light conditions. This highlights the crucial role of the lateral line system in hunting for prey in sandy environments. While fish may also rely on other senses such as sight and smell, the lateral line system is essential for successfully detecting prey in their natural habitats, particularly in darkness.
The Aquarium
For a harem consisting of one male and multiple females (the natural social structure), we recommend having an aquarium that is at least 160 centimeters in length. If you plan to have multiple pairs, a significantly larger aquarium will be necessary, with the exact size depending on the number of pairs. While there are no specific guidelines for the number of liters needed per pair, it is crucial to have a spacious setup to prevent territorial conflicts. A minimum of 400 liters is often suggested for a group.
To set up the aquarium, combine rocks and sand. The rocks will provide hiding places and serve as territory markers, while the sand will mimic a natural bottom. It is best to use fine, round sand, such as filter sand, to prevent injury to the fish. While plants are not necessary, you may add some hardy species like Valisneria, as long as they do not obstruct the fish’s movement. The setup should include open swimming spaces and hunting areas, along with enough hiding spots for the fish to feel secure.
The ideal water parameters for Aulonocara stuartgranti are a pH of 7.5-8.5 and a hardness (dH) of 4-25°. The temperature should be between 22 and 26°C. Regular water changes (20-30% per month) are crucial for maintaining water quality.
Aulonocara stuartgranti can be housed with other peaceful, medium-sized Malawi cichlids, such as Cyrtocara moori, Otopharynx, Placidochromis, and Copadichromis. However, mbuna—aggressive, rock-dwelling Malawi cichlids—are generally not suitable tankmates unless the aquarium is very large and provides plenty of hiding spaces. It is crucial to keep only one species of Aulonocara in the aquarium to prevent hybridization. Additionally, housing multiple males of the same species in a confined space can lead to aggression and conflict.
Breeding aquarium and conditioning
A special breeding aquarium is not necessary for Aulonocara stuartgranti. You can breed them in an aquarium where other species are also kept. Make sure that you do not keep other Aulonocara species in the aquarium to prevent crossbreeding. If you really want to breed larger quantities of this species and catch the females more easily, then a breeding aquarium is more convenient.
To successfully breed this species, it is best to keep them in a harem consisting of one male and three or four females. While a female broods the eggs, he can focus his attention on the other females.
You don’t need a special diet to get them to breed. Good food with occasional live or frozen food is enough.
The spawn
The mating ritual begins as soon as the male detects that a female is ready to lay eggs. He searches for a spot in the sand to create a shallow hole, often selecting a sheltered area between some rocks. At this time, the male’s colors are at their brightest. The courtship display is quite a spectacle; he swims briskly past the female, spreads his fins wide, and exhibits trembling movements to showcase his flank. He continues this behavior until the female is ready to move to the spawning site.
In the breeding pit, the couple circles each other. The female lays one or a few eggs in the sand, while the male fertilizes them as they continue to circle. Afterward, the female continues to circle and takes the eggs into her mouth. In total, about 15 to 40 eggs are laid and collected in this manner. Once the eggs have been safely taken in by the female, the male’s role is complete, and he does not participate in raising the young fish.
Raising the young Aulonocara stuartgranti fry
After laying her eggs, the female fish seeks shelter among the rocks, where she broods the eggs in her mouth. If you observe her throat, you will notice a thickening where the eggs are held. The eggs hatch after a few days, but she does not yet release the young fish. The fry continue to rely on their yolk sac for nourishment for some time. It is only 20 to 22 days after laying the eggs that the female releases the young fish among the rocks.
In an aquarium with other adult fish, young fish are quickly eaten. Only a few survive if there are sufficient hiding places among the rocks.
To successfully raise more fry, it’s best to catch the female fish approximately 14 to 16 days after spawning. Once you do that, place her in a breeding aquarium that has a sandy bottom, a small filter, and a heater. Ensure there are hiding places for the female to conceal herself. After the fry are released, the female typically does not eat them right away, giving you ample time to catch her and return her to the main aquarium.
You can feed the fry with finely ground flake food and, for example, artemia.
Particularities
Below are some details about Aulonocara stuartgranti that were not covered in the previous chapters:
- Color Morphs and Taxonomic Confusion: There is considerable variation in the color patterns of A. stuartgranti depending on geographic location. Several morphs, such as “Maleri,” “Maulana,” “Cobue,” and “Ngara,” were previously regarded as separate species (e.g., A. hansbaenschi and A. steveni); however, they are now generally considered synonyms of A. stuartgranti. However, the exact taxonomic status of some populations remains debated, and some morphs, such as “Maleri” and “Mbenji,” may still be classified as separate species. Additionally, the Chitimba Bay population is sometimes incorrectly sold under the name “A. masoni.”
- Diet and Sensory Adaptations: The fish possesses a highly developed lateral line system, characterized by enlarged canals and neuromasts, which enable it to detect small invertebrates in the sand, even in low-light conditions. This “sonar feeding” behavior is a crucial adaptation for survival in their natural habitat. In an aquarium setting, they will eat a variety of foods, but it is recommended to provide a diverse diet consisting of high-quality dry, live, and frozen options.
- Behavior and Social Structure: Males are territorial, particularly during the breeding season, and defend their spawning sites aggressively. They typically live in small groups that consist of one dominant male and several females. It is important to carefully consider the male-to-female ratio in an aquarium to prevent aggression.
Conclusion
Aulonocara stuartgranti is a relatively easy-to-keep Malawi cichlid, suitable for beginner aquarists with some prior experience. To ensure the well-being of this species, a spacious aquarium with a sandy bottom and rocks is essential. Maintaining stable water parameters is important, with a pH range of 7.5 to 8.5 and a temperature between 22 and 26°C. It is advisable to keep one male with several females to prevent aggression among the fish. This species is particularly interesting due to its striking color variations and unique “sonar feeding” behavior.
The taxonomic classification of A. stuartgranti is complex, with numerous color variants that were once considered distinct species. The fish’s lateral line system, which features enlarged canals, is crucial for detecting prey. While breeding A. stuartgranti is relatively straightforward, caring for the fry requires careful attention to ensure a high survival rate. Overall, A. stuartgranti is an attractive fish that is fairly easy to keep, as long as its basic needs are met.
Video
Author
John de Lange
Copyright images
Walter Deproost
Enrico Richter
Malawi Kaplan
Suephoto (originele website niet meer online)
Geographical variants
Aulonocara stuartgranti – Hansbaenschi
This variant of Aulonocara stuartgranti is found in the southeastern region of Lake Malawi. They are exclusively located in four sites: Masinja, which is also the type location, Fort Maguire, Mara Point, and Thumbi West Island. Unlike many other Aulonocara species, they inhabit relatively shallow waters, typically at depths of about 4 to 6 meters.
Copyright images: Malawi Kaplan
Aulonocara stuartgranti – Maulana
Aulonocara stuartgranti – Maulana occurs in the wild only in Chitimba Bay.
Copyright images: Malawi Unlimited
Aulonocara stuartgranti – Mdoka
Copyright images: John de Lange
Aulonocara stuartgranti – Ngara
This variant of Aulonocara stuartgranti from Ngara is also called Flametail in the trade.
Copyright images: John de Lange; Enrico Richter
Aulonocara stuartgranti – Usisya
Copyright images: John de Lange
