| 1. Conservation Status |
|---|
| Scientific Name | Sahyadria denisonii |
| Common Name | Denison Barb / Roseline Shark |
| Family | Cyprinidae |
| IUCN Status | Endangered (EN) |
| Distribution | Western Ghats, India — Kerala & Karnataka hill streams |
| Notes | Wild populations declining due to over‑collection and habitat degradation; captive propagation essential for ex‑situ conservation. |
| 2. Natural Habitat & Ecology |
|---|
| Habitat Type | Fast‑flowing, highly oxygenated hill streams; shaded riparian corridors |
| Water | pH 6.5–7.2; GH 4–10; high dissolved oxygen; cool monsoon‑driven fluctuations |
| Substrate | Rounded stones, gravel beds, submerged roots, leaf accumulations |
| Behaviour | Rheophilic shoaling cyprinid; rapid darting movements; peak activity at dawn |
| 3. Water Chemistry Requirements |
|---|
| Temperature | 22–26°C (spawning peak: 23–24°C) |
| pH | 6.5–7.2 |
| Hardness | GH 4–10; KH 2–6 |
| Flow | Strong laminar flow; high dissolved oxygen saturation |
| Lighting | Moderate; shaded zones preferred |
| 4. Social Structure & Behaviour |
|---|
| Group Dynamics | Spawns best in groups of 8–12 adults |
| Male Behaviour | Intensified red lateral stripe; parallel swimming displays |
| Female Behaviour | Deeper‑bodied; increased abdominal fullness pre‑spawn |
| Territoriality | Low; brief competitive bursts during spawning |
| 5. Conditioning Protocol |
|---|
| Duration | 2–3 weeks |
| Diet | Live daphnia, mosquito larvae, bloodworms; spirulina‑rich prepared foods |
| Environmental Stability | High oxygenation; strong flow; pristine water quality |
| Indicators | Males intensify colour; females show gonadal swelling |
| 6. Spawning Strategy |
|---|
| Method | Open/substrate egg‑scatterer; no parental care |
| Spawning Sites | Coarse gravel, fine‑leaved plants, high‑flow zones |
| Spawning Behaviour | Early‑morning spawning; rapid circling; adhesive eggs scattered into substrate |
| Parental Care | None; adults must be removed immediately |
| 7. Spawning Triggers |
|---|
| Pre‑Trigger | Strong flow; high oxygen; stable temperature |
| Trigger Event | Large cool water change (20–30% at 2–4°C lower) |
| Additional Stimuli | Increased aeration; dawn light transition |
| 8. Eggs & Incubation |
|---|
| Clutch Size | 50–150 eggs |
| Egg Type | Adhesive; settle between gravel interstices |
| Incubation | 24–36 hours at 24–26°C |
| Notes | High oxygen essential; eggs sensitive to sedimentation |
| 9. Larval Development |
|---|
| Day 0–2 | Yolk sac absorption; limited mobility |
| Day 3–4 | Free‑swimming; swim bladder inflation |
| Day 5–14 | Require microscopic foods; rapid growth with high oxygen |
| Week 2–4 | Colouration begins forming; shoaling behaviour develops |
| 10. First Foods & Feeding Schedule |
|---|
| Stage 1 (Day 3–7) | Rotifers, microworms |
| Stage 2 (Day 5–14) | Small‑strain Artemia, micro‑foods |
| Stage 3 (Week 2–4) | Artemia, powdered fry diets |
| Stage 4 (4+ weeks) | Live foods; fine pellets |
