Yunnanilus cruciatus, commonly known as Vietnamese Multi Banded Zebra Loach, is a fascinating freshwater fish species found in the rivers of Southeast Asia. These small loaches are known for their distinctive markings on their bodies, which give them their name.
Yunnanilus cruciatus is a fairly hardy species and can be recommended even for beginners. These little active fish require warm temperatures and slightly acidic water to thrive.
In this guide, I gathered everything we currently know about Yunnanilus cruciatus including tank setups, habits, diets, compatibility, etc.
Quick Notes about Yunnanilus Сruciatus
| Name | Vietnamese Multi-Banded Zebra Loach |
| Other Names | Hovering Zebra Loach, Pygmy multi-stripe loach, Banded dwarf loach, and Vietnamese Striped loach |
| Scientific Name | Yunnanilus cruciatus (Micronemacheilus cruciatus, Nemacheilus cruciatus) |
| Water type | Freshwater |
| Tank size (optimal) | 10 gallons (~40 liters) |
| Keeping | Easy-medium |
| Breeding | Difficult |
| Size | 1.4 – 1.6 inches (3.5 – 4 cm) |
| Optimal Temperature | 72 – 82°F (22 – 28°C) |
| Optimal PH | 5.5 – 7.5 |
| Optimal GH | 1 – 10 |
| Dwellers | Middle-bottom |
| Nitrate | Less than 80 |
| Diet | Omnivore |
| Temperament | Peaceful |
| Life span | up to 5 years |
| Color Form | Silver or yellowish with dark bands |
Taxonomy of Yunnanilus Сruciatus
Loaches belonging to Nemacheilidae are a taxonomically challenging family of freshwater fish. There are more than 47 genera and 756 species in Nemacheilidae.
In some cases, species can be so similar that morphological variation is often inconsistent with molecular evidence.
In 1944, Swedish zoologist Carl Hialmar Rendahl (1891-1969) described this species as Nemacheilus cruciatus and established the genus Micronemacheilus for it
In 2001, Freyhof, J. and D. V. Serov transferred all members of Micronemacheilus to the newly erected genus Traccatichthys, except Nemacheilus cruciatus, which was moved to Yunnanilus and as Micronemacheilus was placed in its synonymy.
Etymology of Yunnanilus Сruciatus
The genus name “Yunnanilus” is derived from the region of Yunnan in China, where some species of loaches are found.
The species name “Cruciatus” likely draws inspiration from the Latin word “Cruciate or Crux”, meaning “cross-shaped,” which beautifully reflects the distinctive cross markings on the fish.
Distribution of Yunnanilus Сruciatus
Yunnanilus cruciatus is endemic to Vietnam. These fish can be found in the coastal rivers of central Vietnam from the An Lao River (Binh Dinh Province) to the Phong Nha River (Quang Binh Province).
Habitat of Yunnanilus Сruciatus
This species prefers shallow and slow-moving waters with dense aquatic vegetation and the substrate is muddy and sandy.
Description of Yunnanilus Сruciatus
Vietnamese Multi-Banded Zebra Loach is a very small freshwater fish. The typical adult size of this species ranges from 1.4 to 1.6 inches (3.5 to 4 centimeters) in length.
Distinguishing characteristics of Yunnanilus cruciatus:
- Body shape. The body is long and compressed laterally.
- Head. This species has well-separated anterior and posterior nostrils. The cheeks are scaleless.
- Papillae. There are two pairs of large papillae in the median portion of the lower lip.
- Eyes. The eyes are medium-sized; the eye diameter is greater than the interorbital distance.
- Сoloration and pattern. The body coloration is usually silver or yellowish. This species has distinct 14–18 black vertical bars from the operculum to the caudal peduncle. Spaces between bars are wider than bars. The lateral line is incomplete.
- Fins. The pectoral fin has 8–10 branched rays; the caudal fin has 16 branched rays. The anal fin is straight.
Lifespan of Yunnanilus Сruciatus
Currently, there is no data available on the maximum lifespan of Yunnanilus cruciatus in the wild.
In aquariums, this species generally lives for 3 – 5 years, if appropriately cared for.
Typical Behavior of Yunnanilus Сruciatus
Temper:
Vietnamese Multi-Banded Zebra Loaches are very peaceful fish. Despite the existence of hierarchy, the dominant individuals are not aggressive towards others. All conflicts are usually resolved without causing any harm. They do not nip.
Sociality:
Even though this is not a schooling fish, they are still very social animals. They enjoy chasing each other and staying in groups.
Therefore, it is recommended to keep them in groups of at least 8-10 individuals to ensure their well-being and encourage natural behavior.
Being in a group allows them to engage in natural behaviors, which will reduce stress and improve their overall well-being.
Activity:
Yunnanilus cruciatus is very energetic and playful. They are absolutely not shy fish if there are no fish that can bully them.
They enjoy nudging each other with their little noses and frolicking.
These little fish are also good jumpers. So, you need to cover the tank or lower the water level by at least a few inches.
Placement in Tank:
Yunnanilus cruciatus spends most of the time in the open, often checking the bottom of the tank and hovering in midwater.
They enjoy exploring their environment and are particularly fond of areas with dense vegetation or places to hide.
Features:
- Social: Yes
- Activity: High
- Placement: Middle and bottom dwellers
- Peaceful: Yes
- Nippers: No
- Jumpers: Yes
Feeding Yunnanilus Сruciatus
This species is a diurnal omnivore. Yunnanilus cruciatus is not very picky eaters. Generally, they will happily consume dry and freeze-dried foods such as flakes, pellets, and crisps as long as it is adapted to their mouth size.
In the aquarium, Yunnanilus cruciatus can be fed with a wide variety of live food such as:
- brine shrimp (artemia salina),
- Artemia nauplii,
- daphnia,
- fruit flies,
- moina,
- detritus worms,
- vinegar eels,
- mosquito larvae,
- cyclops, etc.
How to feed Yunnanilus Сruciatus:
This is a diurnal species, so it is better to feed them in the morning. Use the «five-minute rule».
Ideally, feed them in small portions (at least 2 times a day) rather than a large amount once a day. This mimics their natural feeding behavior and helps prevent overfeeding and digestive issues.
Features:
- Diet Type: Omnivore
- Food Preference: Meat
- Feeding Frequency: Daily
Are Yunnanilus Сruciatus Plants Safe?
Yes, this species can be kept in planted tanks. They will not eat any healthy plants in the tank. This species does not eat living plant material.
Keeping and Caring for Yunnanilus Сruciatus
Even though this species is pretty hardy and can be easily recommended even for beginners, it is highly recommended not to add them right after completing the aquarium cycling process. Wait for at least a couple of weeks until the balance is established.
Tank size:
The minimum recommended tank size for the group of 8-10 fish is 10 gallons (40 liters).
Despite their small size, Yunnanilus cruciatus should not be kept in small tanks due to their active behavior. Additionally, they need horizontal swimming space more than depth.
Important: Do not forget that this species is jumpers! So, it is imperative to take measures: use a tight-fitting lid, lower the water level, use floating plants, etc.
Water parameters:
Temperature: Ideally, this species needs water temperatures ranging between 72 to 82°F (22 to 28°C). They tolerate cooler temperatures (up to 64°F or 18°C) in winter if acclimated slowly.
pH: The ideal pH range is between 5.5 – 7.5. In their natural environment, they thrive in slightly acidic waters.
Hardness: The tank should preferably have soft to medium water hardness as well. However, anything in the 1 – 10 GH range is acceptable. They do not like very hard water.
Lighting:
Subdued lighting will be the best choice for Yunnanilus cruciatus.
However, if you decide to keep these fish in planted tanks, lighting should be adapted to the needs of plants.
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Flow:
They do not like strong currents. Therefore, still or very slow water currents are recommended for tanks housing this species.
Substrate:
Their natural environment is composed of mud and fine sand.
Avoid coarse gravel. Its sharp edges can injure/scratch the body of the fish as they swim in the lower regions of the tank.
Filtration:
No special requirements.
As long as you have got the filter that works great with the size of the tank you have got you will be fine.
Decorations:
Make sure to provide plenty of dark hiding spots using plants, rocks, stones, driftwood, coconuts, cork bark pieces, leaves, PVC pipes, and other decorations to enrich their environment.
Decorations provide hiding places (shelter and protection) and minimize their stress.
Breeding Yunnanilus Сruciatus
Unfortunately, the reproductive process of this species is practically unexplored in scientific literature. Breeding them in aquariums has proven to be a challenge for almost everyone.
There are literally only a few cases that describe this, with one being documented by a Russian aquarist Vir. However, even he pointed out that it is entirely unclear what triggered it.
According to the scarce information:
- Yunnanilus cruciatus is an egg-scattering spawner.
- Parents do not care for their fry.
- The male swam behind the female, nudging her abdomen with his head and exhibiting a somewhat agitated behavior.
- Females release 10-20 eggs.
- After 1 week, the fry become very active swimmers.
- After 2 weeks, the fry is about 0.4 inches (11 – 15 mm) long.
- Around the age of three weeks, stripes become visible. Their behavior also slightly changes – they start swimming alongside each other, resembling the characteristic behavior of adult fish.
- At the age of 3-4 weeks, with a size of about 15-19 mm, the fry become miniature replicas of adult fish, both in appearance and behavior. The longitudinal stripe, however, may not be strongly pronounced yet. And they spend almost all their time sharpening something.
Yunnanilus Сruciatus and Suitable Tankmates
This is a very friendly fish that is suitable for smaller tanks but be sure of it that they still have sufficient swimming space for them.
When choosing tankmates for this species, it is important to consider their size, behavior, and compatibility with other species in the aquarium. They cannot compete with other species and might be targeted for bullying.
Fish:
If you still decide to keep this species in community tanks, its tank mates should be all small fish species that are not big enough to eat or harass them. Ideally, you need to choose species that prefer warm and slightly acidic aquarium water such as:
- Neon Tetras,
- Endlers,
- Pygmy Cory,
- Guppy,
- Danio rerio,
- Tetraodon travancoricus,
- Poecilia sp.,
- Harlequin Rasboras,
- Clown Killifish,
- Least Killifish,
- Otocinclus, etc.
Shrimp:
Yunnanilus cruciatus will not harm adult or juvenile dwarf shrimp.
However, newly hatched shrimp are tiny enough (0.03 inches or 2 mm) to fit in their mouth. So, they will not waste their opportunity to snack on them from time to time.
Snails:
Yunnanilus cruciatus is compatible with any freshwater snail. They do not eat them.
Avoid:
- Large and/or aggressive, and/or boisterous fishes.
- Keep them away from all types of crayfish and most types of freshwater crabs.
- Even small African Dwarf Frogs can and will try to catch them whenever possible.
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In Conclusion
Yunnanilus cruciatus is relatively undemanding in care, compatible with many other fish species that can thrive in similar conditions. It boasts an original pattern, and a small size, and makes for a good candidate for a community aquarium.
Unfortunately, it is almost impossible to breed them in captivity.
References:
- Du, Li-Na, Jian Yang, Rui Min, Xiao-Yong Chen, and Jun-Xing Yang. “A review of the Cypriniform tribe Yunnanilini Prokofiev, 2010 from China, with an emphasis on five genera based on morphologies and complete mitochondrial genomes of some species.” Zoological Research42, no. 3 (2021): 310.
- Luo, Fuguang, Jie Huang, Tong Luo, Jun Yang, Huanjia Zhou, and Yanhong Wen. “Complete mitochondrial genome and phylogenetic analysis of Yunnanilus pulcherrimus (Cypriniformes, Nemacheilidae).” Mitochondrial DNA Part B4, no. 1 (2019): 1269-1270.
- Зворыкин, Дмитрий Дмитриевич. “Список рыб, населяющих внутренние водоёмы Вьетнама.”Экология внутренних вод Вьетнама (2014): 256-278.
- Freyhof J, SerovDV. 2001. Nemacheiline loaches from Central Vietnam with descriptions of a new genus and 14 new species (Cypriniformes: Balitoridae). Ichthyological Exploration of Freshwaters, 12(2): 133- 191.