Parosphromenus tweediei

Overview

Parosphromenus tweediei is a black-water gourami from western Johor. Male fins show a broad vivid red band inside a black near-edge band. Older aquarium records often misidentify it as Parosphromenus deissneri, so names need to be interpreted with provenance.

Distribution & habitat

Records center on western Johor, Peninsular Malaysia, with the type locality in the Pontian area. Local losses have been reported at former sites in Melaka and Ayer Hitam. Forest clearance and land conversion have greatly reduced habitat.

Peat forests and connected streams provide shade, very low mineral content, and dark acidic water. The type locality was a partly degraded tea-colored stream around pH 4.0. Persistence in remnant channels does not imply broad tolerance.

Aquarium setup

Allow about 40 × 20 cm for a pair. Roots, wood, leaves, pots, and pipes create shade and caves. A bare bottom simplifies breeding maintenance. Shade-tolerant plants and floating cover suit dim light; leaf microorganisms supplement fry food.

Maintain extremely soft acidic water with negligible carbonate hardness, potentially using reverse osmosis. Only use a mature aquarium. Gentle sponge filtration and weekly changes of about 5–10% avoid long neglect followed by large changes. Filterless pairs require controlled feeding and rigorous upkeep.

Diet & feeding

It chiefly eats tiny aquatic invertebrates and needs varied small live foods, including brine shrimp nauplii, Daphnia, Moina, mosquito larvae, and microworms. Dry food is usually refused, and occasional frozen-food acceptance should not make it the entire menu.

Behaviour & compatibility

A species pair preserves identity and favors natural fry survival. Mixed-sex groups can be maintained, but extra adults generally reduce offspring survival. Do not mix similar females from related species because misidentification and hybridization are possible. Any companions must be tiny, calm, and suited to the same conditions.

Sexual dimorphism

Male fins carry broad red bands inside black near-edge bands, with fine pale outer margins. A narrow blue line sometimes separates red and black, and parts of the red band may themselves turn blue, especially in the dorsal and anal fins. Pelvic fins are dark with basal green iridescence and black filament tips.

Females lack bright bands and pale to yellow near spawning. Both sexes change color with mood and may show an oblique eye mark during courtship.

Breeding

Males display head-down and defend a small cave. Temporary pairs attach eggs overhead after spawning embraces, sometimes adding a few bubbles. Inexperienced fish may drop or eat eggs.

The female guards outside while the male tends the brood. Hatching occurs after about 24–36 hours, mobility four to six days later, and full departure another three to five days afterward, ending care. Start with Paramecium or rotifers, then brine shrimp nauplii. Mature complex aquariums may retain young naturally; simpler ones favor separate rearing.

Notes

The complete red-black-blue pattern and locality are more useful than broad color labels. Historical deissneri accounts include misidentified fish and cannot all be assigned automatically to this species or to true Parosphromenus deissneri.