| 1. Conservation Status |
|---|
| Scientific Name | Parosphromenus harveyi |
| Common Name | Harvey’s Licorice Gourami |
| Family | Osphronemidae |
| IUCN Status | Critically Endangered (CR) |
| Distribution | Endemic to peat swamp forests of Peninsular Malaysia |
| Notes | Severely threatened by peatland destruction, drainage, and oil‑palm expansion. Captive propagation is essential. |
| 2. Natural Habitat & Ecology |
|---|
| Habitat Type | Extreme blackwater peat swamps; dense canopy; minimal light penetration |
| Water | pH 3.0–4.5; conductivity 10–40 µS/cm; heavy humic acids |
| Substrate | Leaf litter, peat, submerged roots |
| Behaviour | Secretive; males defend micro‑caves; pair‑bonding during courtship |
| 3. Water Chemistry Requirements |
|---|
| Temperature | 24–26°C |
| pH | 3.5–4.5 (spawning), 4.0–5.0 (grow‑out) |
| Conductivity | 10–40 µS/cm |
| Tannins | High; catappa leaves, peat extract, alder cones |
| Lighting | Very dim; floating plants recommended |
| 4. Social Structure & Behaviour |
|---|
| Group Dynamics | Best kept as pairs or trios (1M:2F) |
| Male Behaviour | Displays intense iridescent colours during courtship; guards nest |
| Female Behaviour | Inspects caves; initiates spawning by body‑curving |
| Territoriality | Low outside breeding; high around nest sites |
| 5. Conditioning Protocol |
|---|
| Duration | 2–3 weeks |
| Diet | Live foods only: grindal worms, mosquito larvae, daphnia, micro‑worms |
| Environmental Stability | No large water changes; maintain ultra‑soft water; keep tannins high |
| Indicators | Males intensify colour; females plump with roe |
| 6. Spawning Strategy |
|---|
| Method | Cave‑spawning bubble‑nest builder |
| Nest Sites | Film canisters, half‑coconut shells, leaf pockets, root tangles |
| Spawning Behaviour | Male leads female to cave; embraces; eggs adhere to cave ceiling |
| Parental Care | Male guards eggs and fry until free‑swimming |
| 7. Spawning Triggers |
|---|
| Pre‑Trigger | Ultra‑soft water (10–20 µS/cm), heavy tannins, stable temperature |
| Trigger Event | Small cool water change (5–10%); fresh botanicals added |
| Additional Stimuli | Lower light further; increase leaf litter depth |
| 8. Eggs & Incubation |
|---|
| Clutch Size | 20–60 eggs |
| Egg Type | Adhesive; attached to cave ceiling |
| Incubation | 24–36 hours at 25°C |
| Male Role | Guards eggs; repairs nest; retrieves fallen eggs |
| 9. Larval Development |
|---|
| Day 0–2 | Larvae remain in cave; yolk sac absorption |
| Day 3–4 | Free‑swimming; male may still guard |
| Day 5–14 | Extremely small fry; require microfoods; sensitive to light |
| Week 2–4 | Colour begins forming; labyrinth organ developing |
| 10. First Foods & Feeding Schedule |
|---|
| Stage 1 (Day 3–7) | Infusoria, rotifers, paramecium |
| Stage 2 (Day 5–14) | Vinegar eels, microworms, tiny Artemia nauplii (if tolerated) |
| Stage 3 (Week 2–4) | Moina, powdered fry foods, micro‑daphnia |
| Stage 4 (4+ weeks) | Small live foods; fine pellets |
| 11. Grow‑Out Requirements |
|---|
| Tank Size | 40–60L for early grow‑out |
| Water | Soft, acidic, tannin‑rich; avoid sudden changes |
| Flow | Minimal; gentle sponge filtration |
| Water Changes | 5–10% every 2–3 days |
| Density | Low density improves growth; high density increases stress |
| Culling | Select against deformities, weak colour, poor nest‑building males |
| 12. Genetic Management |
|---|
| Practices | Maintain multiple lines; avoid sibling pairings; track lineage; avoid mixing with other Parosphromenus species |
| 13. Conservation Notes |
|---|
| Threats | Peat swamp drainage, agriculture, pollution, habitat fragmentation |
| Status | One of the most threatened licorice gouramis |
| Goal | Establish stable captive metapopulations with high genetic integrity |
| 14. Recommended Breeding Setup |
|---|
| Tank | 20–40L blackwater tank |
| Substrate | Leaf litter + peat + botanicals |
| Flow | Minimal; air‑driven sponge filter |
| Water | pH 3.5–4.5; conductivity 10–40 µS/cm |
| Group | Pair or trio |
| Trigger | Cool soft‑water change + fresh leaves |
| Egg Care | Male guards; remove female after spawning if aggressive |
| Fry | Infusoria → microworm → Moina |
| Grow‑Out | Ultra‑soft water; very low light; frequent tiny water changes |
