Maximum size : 13 cm

Porthole Rasbora - Rasbora cephalotaenia : Complete Fish Profile & Care Guide

Table of contents

Introduction

The Porthole Rasbora (Rasbora cephalotaenia) may not be as well-known in the aquarium trade, but it is a fascinating species that would make a superb addition to any friendly community aquarium featuring Southeast Asian or Indian fish. These hardy, active and peaceful fish thrive in groups of six or more, showing off their beautiful colours to full effect in the company of their own kind.

Porthole Rasboras are suitable tankmates for similarly-sized Rasboras, Loaches, peaceful Barbs and Gouramis. However, with their active nature, these fish require plenty of swimming space; therefore, an aquarium of at least 255 litres is needed.

Biotope aquariums are ideal for Porthole Rasboras, with soft, sandy substrates, driftwood tangles, roots, shaded areas, dried leaf litter, peat and dim lighting. Using tannin-stained waters from wood and decomposing detritus will further enhance their natural habitat. These beautiful fish can grow up to 13 cm in length, and their silver bodies can appear pinky blush in certain lights. A striking horizontal line of dark dots can also be seen running along their bodies.

Porthole Rasbora Photos

Sexual Dimorphism

Distinguishing between male and female Porthole Rasboras can pose a challenge. Nonetheless, one can identify a mature female Rasbora by its rounder abdomen and slightly larger size compared to its slimmer, smaller male counterparts.

Quick Facts

Scientific NameRasbora cephalotaenia
Other NamesNone
ClassificationActinopterygii
OrderCypriniformes
FamilyCyprinidae
GenusRasbora
OriginsChina , Vietnam , Laos
Max Size13 cm
TemperamentPeaceful
Aquarium LevelMiddle - Top
DifficultyBeginner - Intermediate
ShoalingYes
Best kept asGroups 6+
Diet & FeedingOmnivore
ReproductionEgg-Scatterer
LifespanUp to 5 Years

Water Parameters

Water TypeFreshwater
pH 5.0 - 7.5
GH 1 - 12
Ideal Temperature
71 - 79
21 - 26

Natural Habitat

Porthole Rasboras are a fascinating species distributed across several regions in Southeast Asia. They can be found in the Thu Bon River in central and northern Vietnam, the Pearl River Basin in southeastern China, the Nam Ma River Basin in Laos, and they also occur in the Nandujiang and Wanquanhe River on Hainan Island. These fish typically inhabit small to medium rivers and streams with slow-moving blackwater flows. They are also sometimes found in rice fields, canals, and ditches. In these natural habitats, the decomposition of organic matter releases chemicals and tannins that stain the water brown, creating a unique environment for these fish to thrive. Fallen leaves, twigs, and branches commonly cover the substrate, and the water is soft, acidic, and somewhat dark due to the forest canopy above.

Breeding

Porthole Rasboras are a species of egg-scattering Cyprinid fish that do not exhibit any parental care. Nonetheless, if they are in good health, they will spawn frequently. In an established, densely planted aquarium, a few fry may start to appear without any interference. If you want to increase the number of fry, you will need to take a more controlled approach. You can condition a group of adult fish together and set up a separate breeding tank, which should be dimly lit and have a bare bottom or a large mesh that allows eggs to fall through but prevents adults from reaching them. Artificial grass matting can also be used. The water should be slightly acidic to neutral, and the temperature needs to be somewhat higher than in the regular aquarium. An internal power filter can be initially added to direct flow down the entire tank length. 

After conditioning the adult fish and identifying the full-egg females, introduce one or two pairs into the breeding tank. Spawning can be stimulated by gradually adding small amounts of cool water every few hours and feeding the fish small amounts of live and frozen food. Several spawning sessions are likely to occur before the female has run out of eggs. If they fail to spawn straight away, leave them, but if there are no eggs after three or four days, return them to their regular aquarium and choose another pair.

Once all the eggs have been laid, remove the adults from the breeding tank to prevent them from consuming the eggs. The incubation period is temperature-dependent, and the eggs will usually hatch between 18 and 48 hours later, with the young becoming free-swimming 24 to 48 hrs after that. Therefore, it is best to initially feed the fry with Paramecium or similar, moving on to baby brine shrimp and microworms once they are large enough to accept them.

Diet & feeding

To maintain optimal health and vibrant colouration, feeding Porthole Rasboras is a straightforward process. These fish are not finicky eaters and will readily accept a variety of foods. It is recommended to supplement their diet with small live and frozen foods, including daphnia, brine shrimp, mosquito larvae, Cyclops, and bloodworms. High-quality dried foods such as crushed flakes, micropellets, and granules should also be included to balance their diet. Regular feeding of a diverse diet will ensure your Porthole Rasboras' best condition and colour.

 

Other Rasboras of interest