Tanichthys sp. 'Vietnam'

Overview

Tanichthys sp. 'Vietnam' is a small schooling fish retained under a provisional name. Bright yellow pelvic and anal fins explain lemon and yellow-white-cloud trade labels. Those labels are not formal names and should not be used to assign it to a different similar species.

Distribution & habitat

It is known from the Da Nang area of central Vietnam. Habitat photographs show a clear stream over mixed small stones. Aquatic plants appear scarce, while grasses and other bankside vegetation are well developed.

Aquarium setup

Allow a footprint of at least around 45 × 30 cm. Dense planting over a dark substrate improves color, with floating plants, roots, branches, and leaves adding cover and diffusing light.

Powerful filtration currents are unnecessary. Modest circulation is sufficient, including in a stream-style arrangement without strong flow dominating every available area.

Diet & feeding

Small insects, worms, crustaceans, and other plankton are suggested natural foods. It feeds easily in captivity. Combine live or frozen bloodworms, Daphnia, and brine shrimp with quality flakes or granules, including some plant- or algae-containing preparations.

Behaviour & compatibility

Very peaceful behavior makes larger or strongly boisterous companions unsuitable. Ten or more conspecifics reduce nervousness and allow males to show color during courtship and rival displays.

Sexual dimorphism

Young fish are difficult to sex. Mature females usually have rounder bellies and slightly greater size. Males brighten during reproductive condition or display, and dorsal and anal fins may become extended with age.

Breeding

Eggs are scattered repeatedly without parental care. A mature planted species aquarium or outdoor container may retain a few young without intervention.

For dedicated breeding, use a dim container with mesh, plastic grass, marbles, fine plants, or spawning mops protecting eggs. Mildly acidic to neutral water toward the warmer end of the established suitable range, with an air stone or air-driven sponge filter, is appropriate.

Introduce one or two conditioned pairs, or about six of each sex in a larger enclosure. Spawning usually follows the next morning. Adults may eat eggs and should be removed within two or three days. Incubation takes roughly 48–72 hours. Free-swimming young may need Paramecium or similar microscopic food before they can take brine shrimp nauplii.

Notes

It has been mistaken for Tanichthys thacbaensis, which occurs farther north in Vietnam. Its yellow pelvic and anal fins differ from the red ones in Tanichthys micagemmae. Both are smaller than Tanichthys albonubes and lack its overall reddish-brown coloration.

Preserve the provisional name and collection context rather than treating a new sales label as evidence of formal scientific description.