Hypancistrus yudja – L174
Hypancistrus yudja was first described by Leandro Melo de Sousa, Erilda Barbosa de Sousa, Renildo de Oliveira Ribeiro, Mark H. Sabaj, Jansen Zuanon and Lúcia Rapp Py-Daniel in 2025. They are sometimes called Ocelot Pleco. Before the official description , they had number L174, officially this is dropped after the description(here you can find explanation about the L numbers).
The genus name Hypancistrus is a contraction of the Greek “hypo” (meaning less than) and “ancistrus” (a reference to the genus Ancistrus), alluding to the reduced number of teeth (especially in the lower jaw) compared to Ancistrus. The species name yudja is a tribute to the Yudjá (also called Juruna), an indigenous people group from the Volta Grande do Xingu region of Brazil. In the Tupi language, Yudjá means “the river owners.” This group has a close connection to the Xingu River and was traditionally involved in catching this species of fish for the aquarium trade.
Description, Behavior and Life Expectancy
Hypancistrus yudja is a small to medium-sized harness catfish, with a maximum overall length of about 8 centimeters. The body is short and tall, widest at the gill lids, tapering to the tail. The dorsal side is light brown to beige in color, with relatively large, dark brown spots and saddles forming a reticular pattern (a network pattern of lines and spots). The ventral side is lighter in color. The head is also light brown to beige with dark markings. The fins are usually light brown to beige, with the same dark brown markings as on the body. The color can vary depending on the age and sex of the animal.
Sex differences: Adult males have a broader and longer head than females. They also develop enlarged odontodes (tooth-like structures) on the cheeks, pectoral fin spines and on most body plates, especially on the tail root. These enlarged odontodes appear to be permanent. Behavioral differences are mainly related to reproduction; males guard eggs and young in a cave.
Juveniles versus adults: Juveniles show a less pronounced reticular pattern than adult fish. The dark spots are often less sharply defined in juveniles and may look more like spots or stripes.
Behavior and temperament: Hypancistrus yudja is a relatively shy and twilight or nocturnal species that spends most of the day in hiding places such as caves and crevices between rocks. They are not aggressive towards conspecifics, provided sufficient space and hiding places are available. However, if there is a lack of space or hiding places , fights may occur. It is recommended to keep them in small groups (for example, 5-6 animals in an aquarium of 50 cm or larger). They are bottom dwellers.
Life expectancy: The life expectancy of Hypancistrus yudja in the wild is unknown. In an aquarium, they can live 3 to 4 years. However, there is evidence that under optimal conditions they can live longer.
Habitat and Ecology
Hypancistrus yudja has so far been found only in Brazil. They live specifically in a small part of the Volta Grande do Xingu, a section of the Xingu River.
They are river fish that live in the Xingu River. They inhabit deep parts of the river, specifically below 15 meters in depth. Their habitat consists of caves and crevices in laterite conglomerates (a type of rock). Little information is available on the presence of underwater vegetation and vegetation along the banks. However, descriptions indicate a rocky bottom with little to no vegetation in the deeper areas where the fish live.
The natural enemies of Hypancistrus yudja are unknown, but it is likely that they are hunted by larger fish and other aquatic animals in their habitat. Their shy behavior and living in deep, sheltered areas indicates a strategy to avoid predation.
The Xingu River has a tropical climate. Seasonal floods or droughts occur in the specific area where Hypancistrus yudja lives, seasonal fluctuations in water levels occur in the Amazon.
Diet
Diet in the wild: The diet of Hypancistrus yudja in the wild is not fully known, but based on its affinity to other Hypancistrus species and their habitat, it can be assumed that they have an omnivorous diet. They probably feed on algae, biofilm (a thin layer of microorganisms on surfaces), small invertebrates and organic waste. The documents indicate that they live in deep parts of the river, where they may also consume small insect larvae or other small animals.
Diet in the aquarium: In the aquarium, Hypancistrus yudja can be fed a varied diet, including high-quality algae wafers, tablets specifically for harness catfish, frozen foods such as daphnia, cyclops, mysis and artemia, and occasional small pieces of vegetables such as zucchini or cucumber. It is important to provide a balanced diet to meet their nutritional needs. Some aquarists have found success by feeding small amounts of clam or shrimp meat. However, it is important to avoid feeding them too much animal food, as this can lead to obesity and health problems. A varied diet with a focus on plant-based foods is recommended.
The Aquarium
For a group of 5-6 Hypancistrus yudja, an aquarium of at least 80-100 liters is recommended. A larger aquarium (for example 150 liters or more) is of course always better, especially if you want to keep several groups. Some sources indicate that a 54 liter aquarium is suitable for a group of 4-6 fish, but this is on the small side and may not provide enough space and hiding places. A larger aquarium is recommended for a healthier and less stressful environment.
The layout should mimic the fish’s natural habitat. Use plenty of rocks, caves and crevices to provide plenty of hiding places. Plants are not immediately necessary, but can be added, provided they can withstand the somewhat higher temperatures this species prefers. A dark background can contribute to the well-being of this shy species. As a substrate, it is best to use sand or fine gravel. Avoid sharp materials that can injure the fish.
The ideal water conditions for Hypancistrus yudja are a temperature of 26-30°C, a pH of 5.5-7.5 and low to moderate hardness (GH 1-8). Regular water changes (e.g. 50% per week) are essential for maintaining good water quality.
Hypancistrus yudja can be kept well with other peace-loving, bottom-dwelling fish that tolerate similar water values and do not pose a threat. Avoid aggressive or large fish that might attack or stress Hypancistrus yudja. Suitable co-inhabitants may include small Corydoras species, certain small tetras, and other small, peaceful armor catfish. It is important to ensure that there is adequate space and hiding places for all fish in the aquarium. It is not recommended to keep multiple species of Hypancistrus in one aquarium, due to the risk of hybridization.
Breeding Aquarium and Conditioning
Several breeding attempts of Hypancistrus yudja are known, both in standard aquaria and in specifically designed breeding aquaria. No single”best” method has been described.
Set up a breeding aquarium with plenty of hiding places in the form of ceramic caves. The caves should be just large enough for a male and closed at the back. Breeding reports show different ratios of males to females. Usually about equal numbers of males and females are placed in the breeding aquarium.
Filter the aquarium with a sponge filter. This keeps the young fish from being sucked in and gives them a surface on which to graze. The water should be reasonably warm with a temperature around 28°C and a neutral pH around pH 7. Direct the flow of a powerhead along the entrance of the ceramic burrows.
Condition the parent fish with a varied diet. For example, feed them with good quality wafers, mosquito larvae, mussel- and shrimp meat.
The spawn
The male selects a suitable and appropriate burrow in which he later plans to incubate the eggs. The inside of the burrow is cleaned by him. The male chooses a suitable cave or hiding place and lures a female. The males actively guard the chosen spot.
The eggs are deposited in the back of the cave by the female and fertilized by the male. After the eggs are deposited, the female’s job is over. The male guards the burrow and fans the eggs.
Raising the Young Fish
The eggs hatch after a few days. The male guards the cave until all the young fish have left the cave. They feed on microorganisms and, for example, crushed flake food.
The best results are achieved in a dedicated breeding aquarium. In a mixed aquarium with other adult fish , the young are often eaten.
Particularities
Various details about Hypancistrus yudja not covered in previous chapters:
- Trade names: The species is sold in the aquarium trade under several names, including “Ocelot Pleco,” “Acari-zebra-marrom,” “zebra-marrom,” “acari-marrom” (Portuguese), and “L174” (L-number). The L number is a designation used in the aquarium trade for undescribed or difficult to identify species.
- Confusion with Hypancistrus zebra: Hypancistrus yudja can easily be confused with H. zebra, especially because of the stripes on the head. Accurate identification requires a thorough inspection of the entire body pattern.
- Limited distribution and endangered status: The species has a very limited distribution in the Volta Grande do Xingu River in Brazil. The construction of the Belo Monte dam is having a negative impact on its habitat and population size, leading the species to be considered critically endangered. Recent dive surveys have failed to find the species in its known habitat, indicating a drastic population decline.
- Captive breeding: Although captive breeding is difficult, successful attempts have been reported. One successful breeding took place in a 54-liter aquarium with specific setup and water parameters. The breeding method includes the use of ceramic caves as hiding places. The young were placed in a separate breeding tank and fed infusoria and later nauplii of artemia.
- Diet: Although the species is considered omnivorous, there is a strong preference for animal foods, such as shrimp, krill , mussels, pieces of raw fish and mosquito larvae. Vegetable food is less liked, and the species is not suitable as an algae cleaner.
- Behavior: The species is relatively shy and nocturnal. They exhibit a more natural behavior in small groups, but can become aggressive in the absence of space and hiding places.
- Genetic variation: The species exhibits considerable genetic variation, resulting in different color patterns. This variation may have adaptive value by preventing predation.
- Taxonomic history: The species was long known in the aquarium trade under the L number L174, before it was officially described in 2025 . The species name yudja is a tribute to the indigenous Yudjá people of the Xingu region.
Conclusion
Hypancistrus yudja is a fascinating but challenging species of fish for the aquarium keeper. Due to their limited distribution and threats in the wild, keeping this species is a great responsibility. They are not beginner fish; successful breeding requires specific knowledge of water parameters, decoration and nutrition. Their shy nature and the need for adequate hiding places must be factored into the aquarium setup. A varied diet, with a focus on animal foods, is essential.
Sources show that successful breeding is possible, but it requires patience and attention to detail. The relatively small size and the possibility of breeding in smaller aquariums do make them of interest to fanciers with limited space. The unique color patterns and relatively unknown behavior make Hypancistrus yudja an intriguing species for experienced enthusiasts willing to take on the challenge. However, it is crucial to keep the species’ endangered status in mind and only purchase fish that come from sustainable breeding programs.
Author
John de Lange
Copyright images
Jonas Hansel – Piranha-info.com (original website no longer online)
References
- Sousa, L.M. de; Sousa, E.B. de; Ribeiro, R.O. de; Sabaj, M.H.; Zuanon, J.; Py-Daniel, L.R. (2025). Two new species of Hypancistrus (Siluriformes: Loricariidae) from the rio Xingu, Amazon, Brazil. Neotropical Ichthyology, 23(1):e240080.
- PlanetCatfish.com. Hypancistrus yudja (Loricariidae) Cat-eLog.
- Fauna Tropica. Hypancistrus yudja “L174” – Breeding report.
