Eirmotus octozona

A Little More Information...

The 8 Bands Barb, marketed under the scientific name Eirmotus octozona, is a tiny Asian cyprinid with a striking pattern. Its silvery body is crossed by dark bands that become especially prominent in soft, calm and well-maintained water. Peaceful and schooling, it does best in a small group in a mature, densely planted aquarium with gentle water movement. Native to western Thailand, this species remains very rare in the aquarium trade. It is offered exclusively by Ton.Fish in Canada, making it an uncommon opportunity for Canadian aquarists seeking a distinctive small Asian fish.

General species description

Eirmotus octozona is a small schooling fish belonging to the Cyprinidae family. It is recognized by its small size, slender body and pattern of several dark vertical bars. Its temperament is generally peaceful, although its tiny size makes it vulnerable to larger or overly active tankmates. Keeping several individuals encourages more natural behavior and improves their confidence. The species benefits from moderate lighting, shaded areas and stable water conditions. Because it is not readily available, it should be considered a fish for a carefully prepared aquarium rather than an improvised community setup. Its commercial availability is very limited, so the aquarium should be planned before purchase.

Geographical origin and biotope

Reference country: Thailand. The species is associated with the Mae Klong River basin in western Thailand, particularly around Kanchanaburi Province. It occurs in small freshwater habitats that are generally calm to moderately flowing, where vegetation, branches and leaf litter provide cover. Slightly acidic to neutral, clean and well-oxygenated water suits its lifestyle. In the aquarium, fine-leaved plants, roots and shaded areas help recreate this setting. Stability is more important than frequent adjustments, especially for this delicate and uncommon aquarium fish. Gentle filtration and regular maintenance are preferable to strong circulation or abrupt changes in water chemistry.

Precise location and local name

The known range of Eirmotus octozona lies within the Mae Klong basin in western Thailand, with particular reference to the Kanchanaburi region. This area includes many small forest streams and tributaries with shaded banks. No commonly used Thai vernacular name is included here. In the aquarium trade, the English name 8 Bands Barb is the most practical way to identify it. Its restricted geographical range helps explain its irregular availability and its status as a very rare fish among specialized retailers.

Appearance and physical characteristics

Eirmotus octozona has a short, slender body that is slightly compressed from side to side. Its base color ranges from silvery beige to pale golden brown, with dark vertical bands crossing the body and giving rise to its common name. The fins are understated and generally translucent, while the eye appears relatively large in proportion to the head. Adult size remains small, making it suitable for a well-structured modest aquarium, but not for unstable containers. Coloration may intensify when the fish is relaxed, kept in a group and viewed against a dark background. Excessive lighting or a lack of shelter may make it timid and cause its markings to fade.

General diet

In the aquarium, Eirmotus octozona accepts a varied diet made up of very small foods. Good-quality micro-pellets, finely crushed dry foods and small frozen foods such as suitable nauplii should be offered. Small portions reduce waste and allow shy individuals to feed successfully. Live or frozen foods can stimulate appetite and support condition, but should not replace a balanced diet. Because the mouth is tiny, oversized pellets are often ignored. The key is food of a very small size, offered regularly without overloading an aquarium that should remain clean and stable.

Essential data

• Name of native river: Mae Klong River basin
• Local name used: no commonly retained local name
• Origin of the scientific name: Eirmotus is the genus name; its etymological origin is not included here
• Etymology of the full name: octozona means eight bands or eight zones
• Common/vernacular names: 8 Bands Barb; eight-banded barb
• Family: Cyprinidae
• Subfamily: no subfamily is included here
• Name pronunciation: ay-er-MOH-tus ok-toh-ZOH-nah
• Discovery: Wolfgang Klausewitz, 1959
• Maximum adult size: about 3 cm
• Water temperature and pH: about 22 to 28 °C; pH around 6.0 to 7.2
• Stream appearance and surrounding vegetation: small shaded streams with riparian vegetation, branches and leaf litter
• Typical tankmates: peaceful small Asian cyprinids, micro-rasboras and adult shrimp of comparable size
• Temperament and behavior: peaceful, schooling and sometimes shy
• Water depth: shallow areas
• Sexual dimorphism: mature females are generally rounder; differences remain subtle
• Bottom structure and flow: sandy or muddy bottom with plant debris; calm to moderate flow

In your aquarium

To succeed with Eirmotus octozona, prepare a mature aquarium with soft, stable water and low nitrate levels. A suitable group, fine-leaved plants, roots and subdued lighting reduce stress and encourage natural behavior. Use gentle flow, since this small fish is not suited to constantly fighting a powerful current. Avoid predatory or clearly larger tankmates, as well as rapid changes in temperature or water chemistry. Its very rare status and exclusive availability from Ton.Fish in Canada make careful acclimation especially worthwhile. Fine, varied foods complete the basic conditions needed for long-term success.