Porthole Rasbora Care Guide - Aquarium Setup, Diet & Breeding

The Porthole Rasbora is a comparatively large member of the rasbora group, with a streamlined, silvery body and a distinctive dark marking along the side. Subtle golden, bronze and greenish reflections can appear across the flanks as the fish moves, while the fins are generally translucent with understated colour.

This species is active but peaceful, spending much of its time in the middle and upper areas of the aquarium. It is most confident when kept in a social group, where the fish often move together through open water and display gentle bursts of schooling behaviour.

In the wild, Porthole Rasboras are associated with shaded Southeast Asian waterways surrounded by dense vegetation. Their habitats may contain tannin-stained water, submerged roots and a thick layer of fallen leaves, although the species can also occur in clearer streams and tributaries.

Compared with many small rasboras sold for community aquariums, Rasbora cephalotaenia has a more substantial adult presence and needs to be planned for accordingly. Its calm nature and attractive, understated markings make it a rewarding choice for a spacious Southeast Asian-themed community aquarium.

Porthole Rasboras are native to mainland and island Southeast Asia, including the Malay Peninsula, Sumatra and Borneo. They inhabit forested, slow-moving streams, tributaries and blackwater environments where leaf litter and submerged vegetation create a shaded habitat.

A group of Porthole Rasboras should be housed in an aquarium of at least 200 litres, with a footprint of roughly 120 cm by 45 cm to provide adequate swimming length. Use a soft sand or fine-gravel substrate, open swimming space and areas of dense planting around the sides and rear. Driftwood, roots, subdued lighting and a scattering of dried leaves can recreate their forest-stream habitat, while gentle to moderate water movement and a secure lid are advisable.

Up to around 15 cm (6 in) in total length. Females may become slightly larger and deeper-bodied than males, while males are usually slimmer.

Porthole Rasboras are omnivores and should receive a varied diet of quality flakes, small pellets and granules, supplemented with frozen or live foods such as bloodworms, mosquito larvae, daphnia and brine shrimp. Offering several appropriately sized foods helps maintain condition and brings out their natural feeding activity. Small portions fed once or twice daily are preferable to allowing uneaten food to accumulate.

Porthole Rasboras are peaceful community fish and can be kept with similarly sized, calm species such as larger rasboras, peaceful barbs, danios, medium-sized tetras, rainbowfish and non-aggressive bottom dwellers. Suitable companions include kuhli loaches, peaceful Corydoras species and smaller plecos, provided the aquarium is large enough for all inhabitants. Avoid highly aggressive or fin-nipping fish, and do not house them with very small species or shrimp that could be swallowed by large adults.

Porthole Rasboras are egg scatterers and are not commonly bred in home aquariums. For the best chance of spawning, condition a group with plentiful small live or frozen foods, then provide soft, slightly acidic water, gentle flow and fine-leaved plants or spawning mops. Adults may eat the eggs, so remove them after spawning or protect them with a spawning grid. The eggs typically hatch within a few days, and the tiny fry need infusoria or another suitably fine first food before moving on to newly hatched brine shrimp.

Females are generally fuller through the belly and may be slightly larger overall. Males tend to have a slimmer profile and can appear more streamlined, although the differences are not always obvious outside mature, well-conditioned groups.