Product Details

Patrick’s Rasbora – Rasbora patrickyapi

Overview:

Patrick’s Rasbora is a rare and elegant blackwater rasbora from Indonesian Borneo, with a slim body, dark lateral markings and subtle warm colour that looks especially attractive in a shaded planted aquarium. Rasbora patrickyapi is a peaceful shoaling fish for aquarists who enjoy quieter, natural-style setups with soft water, botanicals and calm tank mates. It is not a flashy beginner rasbora like a Harlequin, but in the right aquarium it becomes a refined and unusual species for a specialist community.

Key Identification:

Common Name: Patrick’s Rasbora
Other Names: Patrick Rasbora, Patrick Yap’s Rasbora, Blackwater Rasbora, Borneo Rasbora
Scientific Name: Rasbora patrickyapi
Fish Type: Rasbora / Cyprinid
Water Type: Freshwater

Natural Range & Habitat:

Patrick’s Rasbora is endemic to Kalimantan, Indonesian Borneo, where it is associated with lowland blackwater habitats. FishBase records it from shallow, slow-flowing swampy areas next to blackwater streams, including lowland peat swamps and degraded heath forest with peat and silica-sand substrates.

Aquarium Glaser describes the species as restricted in nature to peat swamps in central Kalimantan, where the water can be very acidic. In the aquarium, it should be treated as a soft-water forest rasbora that appreciates clean, stable water, subdued lighting, plants, wood, leaf litter and low stress.

Appearance & Adult Size:

Patrick’s Rasbora has a slender, streamlined body suited to gentle open-water swimming. Colour is usually silvery to amber with a darker lateral stripe or blotching, while mature, settled fish may show warmer tones and subtle fin colour. It is a modest but attractive species that looks best in groups rather than as single specimens.

Adults reach around 5–6 cm, with Aquarium Glaser giving a maximum length of about 5 cm and FishBase-linked summaries reporting up to around 5.7 cm standard length. Females are usually slightly deeper-bodied, while males may appear slimmer and more colourful when displaying.

Aquarium Suitability:

This species is best suited to a peaceful, mature, soft-water aquarium. It works well in blackwater aquascapes, planted tanks, biotope-inspired layouts and quiet community aquariums with floating plants, wood, botanicals and open swimming areas. It is not suitable for aggressive communities, hard alkaline water setups, very bright bare tanks or aquariums with large predatory fish.

Recommended Aquarium Size:

A practical minimum is 70–80 litres for a group, with 90–120 litres or more preferred for a larger shoal and more natural behaviour. A tank length of at least 60 cm is recommended, with larger aquariums giving better swimming space and more stable water quality.

Water Conditions:

Temperature: 23–27°C
pH: 4.5–7.0
Hardness: Soft preferred; avoid very hard alkaline water
Additional Notes: Clean, stable water is essential. Blackwater conditions with tannins, leaf litter and low mineral content are ideal, but captive-acclimated fish can adapt to slightly less extreme conditions if changes are gradual. Aquarium Glaser notes that although the natural habitat has very low pH, the species adapts to normal aquarium conditions provided the water is very clean and bacterial pressure is kept low.

Temperament & Tank Mates:

Aquarium Category: Community Fish

Patrick’s Rasbora is peaceful and should be kept with calm fish of similar size and temperament. Suitable tank mates include small rasboras, peaceful tetras, pencilfish, small gouramis, Otocinclus, Cory-type catfish suited to softer water, small loaches and gentle dwarf cichlids in carefully planned setups.

Avoid large predators, aggressive cichlids, fin-nippers, very boisterous barbs and hard-water specialists. It should be kept in a group of at least 6, with 10 or more strongly preferred. Fishi-pedia also describes the species as naturally shoaling and non-territorial.

Feeding:

Patrick’s Rasbora is a small omnivorous to micro-predatory fish that should be offered fine foods. Feed quality crushed flakes, micro pellets and small granules as the staple, supplemented with frozen or live foods such as daphnia, cyclops, brineshrimp, mosquito larvae and finely chopped bloodworm. Small frequent feeds are better than large portions. A varied diet helps maintain condition, colour and breeding behaviour.

Behaviour in the Aquarium:

This is a midwater to upper-level shoaling fish that becomes much more confident in numbers. It will usually move in a loose group through open shaded areas, especially beneath floating plants or over dark substrate. Males may display subtly within the shoal, but it is not aggressive. It may jump if startled, so a secure lid is recommended.

Care Notes:

Add only to a mature, stable aquarium. Avoid immature tanks, dirty filters, high nitrate and sudden water changes. Subdued lighting, floating plants, botanicals and darker décor will help the fish settle and show better colour. Because this is a blackwater peat-swamp species, avoid rough acclimation into hard alkaline water. It should never be released outdoors, and unwanted fish must be rehomed responsibly.

Recommended For:

Intermediate

Availability:

Rare / Specialist import / Occasional captive-bred availability

Image Disclaimer:

All images are a visual representation of the fish you will receive, made to be as accurate as possible. Natural variation in size, colour, pattern and markings can occur between individual fish.