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Fish_of_Nepal_Altitudinal_Belts_Aquaculture_2025.pptx
- 1. Fish of Nepal’sHigh Hills, Mid- Hills & Terai Class-ready deck for undergraduate Agriculture students (2025) AASHISH KUNWAR, Dept. of Aquaculture Aquaculture in Nepal – Lecture Notes (Prepared for B.Sc. Ag.) · Dec 2, 2025
- 2. Nepal Snapshot (Usein Class) • ≈230+ freshwater fish species; richest in floodplains, moderate in mid-hills, lowest in high mountains • Thermal bands: Coldwater 7–20 °C; Warmwater 15–32 °C • FY 2079/80 (2022/23): Total fish ≈113,736 t (Aquaculture ≈81.5%; Capture ≈18.5%) • Ponds 82,161 t (national mean ~5.57 t/ha): Terai ~5.69; Hills ~4.67; Mountain ~1.67 • Trout raceways ~1,007 t; Cages ~370 t; Rivers Aquaculture in Nepal – Lecture Notes (Prepared for B.Sc. Ag.) · Dec 2, 2025
- 3. High Hills &Mountains – Habitat Profile • Altitude: >1,200 m; cold, fast, clear, high DO; oligotrophic high lakes (e.g., Rara) • Teaching handle: “cold (7–20 °C), clean gravel, high oxygen” • Threats: barriers/peaking flows, gravel mining, exotics, siltation Aquaculture in Nepal – Lecture Notes (Prepared for B.Sc. Ag.) · Dec 2, 2025
- 4. High Hills –Key Species (Nepali / Scientific) • असला (Snow trout) – Schizothorax richardsonii (IUCN VU) – Rara endemics: S. macrophthalmus, S. nepalensis, S. raraensis (two CR) • सहार (Golden mahseer) – Tor putitora (IUCN EN) • कट्ले (Katle/Chocolate mahseer) – Neolissochilus hexagonolepis (often NT regionally) • Hillstream catfishes – Glyptothorax spp. Aquaculture in Nepal – Lecture Notes (Prepared for B.Sc. Ag.) · Dec 2, 2025
- 5. High Hills –Life History & Management • Snow trout: periphyton scraper; spawns Sep– Oct & Mar–Apr on clean gravels • Preferred conditions: fast flow (~3–4 m/s), DO ~10–15 mg/L, pH ~7.5 • Mahseer: migrates to cool tributaries to spawn on gravel; sensitive to barriers • Management: protect spawning gravels; fish passable hydropower; control exotics; ‑ anti poaching ‑ Aquaculture in Nepal – Lecture Notes (Prepared for B.Sc. Ag.) · Dec 2, 2025
- 6. Mid-Hills – Habitat& Systems • Altitude: ~500–2,000 m; runs/riffles, plunge pools; lakes (Phewa, Begnas, Rupa) & Kulekhani reservoir • Key species: Tor putitora, Tor tor, Neolissochilus hexagonolepis; Barilius & Schistura spp. • Cage culture: silver & bighead carp in floating cages (planktivory, low feed) Aquaculture in Nepal – Lecture Notes (Prepared for B.Sc. Ag.) · Dec 2, 2025
- 7. Mid-Hills – CageCulture (Pokhara Lakes) • Species: Silver carp (Hypophthalmichthys molitrix), Bighead carp (Aristichthys nobilis); add Rohu to reduce fouling • Lake differences in growth: Rupa > Begnas > Phewa (typical finding) • Manage inflows & nutrients (e.g., Harpan Khola → Phewa hotspots) • Hydropower & flows: maintain environmental flows; time bed/sand mining away from spawning Aquaculture in Nepal – Lecture Notes (Prepared for B.Sc. Ag.) · Dec 2, 2025
- 8. Terai (Madhesh) –Habitat & Production • Low gradient rivers (Koshi, Narayani, Karnali, Mahakali, Babai), oxbows/beels, canals, paddies, ponds • Pond polyculture backbone: IMC – Rohu (Labeo rohita), Catla (Catla catla), Mrigal (Cirrhinus mrigala) • Chinese carps widely stocked: Silver, Bighead, Grass, Common carp; Pangasius expanding • FY 2079/80: Terai ponds ~75,292 t from 13,243 ha (~5.69 t/ha) Aquaculture in Nepal – Lecture Notes (Prepared for B.Sc. Ag.) · Dec 2, 2025
- 9. Terai – ManagementPriorities • Keep seasonal connectivity: rivers ↔ oxbows/beels/paddies (critical for featherbacks & SIS) • Control sand mining & agricultural runoff; enforce closed seasons during monsoon spawning • Improve seed quality & effluent management in intensive systems (e.g., Pangasius) Aquaculture in Nepal – Lecture Notes (Prepared for B.Sc. Ag.) · Dec 2, 2025
- 10. Species Capsules I– Asalā & Sahār • Snow trout (असला) – Schizothorax richardsonii (VU): scraper; clean gravel spawning (Sep–Oct & Mar–Apr) • Teach: silt smothers eggs; barriers block micro migrations ‑ • Golden mahseer (सहार) – Tor putitora (EN): pre monsoon ascent (Mar–Apr); gravel ‑ spawner; range: Koshi, Narayani, Karnali, Babai • Teach: environmental flows + fish passages + Aquaculture in Nepal – Lecture Notes (Prepared for B.Sc. Ag.) · Dec 2, 2025
- 11. Species Capsules II– Rara Endemics & Trout Culture • Rara endemics: S. macrophthalmus, S. nepalensis (CR), S. raraensis (CR) – cold, oligotrophic, isolated lake system • Rainbow trout aquaculture (Oncorhynchus mykiss): 10–20 °C (opt. 15–18 °C), high DO, clean flows • FY 2079/80 raceway output ~1,007 t; biosecurity against escapes & disease Aquaculture in Nepal – Lecture Notes (Prepared for B.Sc. Ag.) · Dec 2, 2025
- 12. Practical Anchors –Field ID & Water Quality • Quick ID: Asalā (subterminal mouth) | Mahseer (large scales, forked tail) | Featherback (knife body, long anal fin) | IMC mouth cues • Coldwater trout: 10–20 °C (best 15–18 °C), DO >7–8 mg/L; Pond carps: 20–32 °C, DO >5 mg/L, pH neutral–alkaline • Production talking point: ~114k t total; ponds ~82k t (mainly Terai); capture ~21k t Aquaculture in Nepal – Lecture Notes (Prepared for B.Sc. Ag.) · Dec 2, 2025
- 13. Viva Questions –One liners to ‑ Remember • Why clean gravel for snow trout? Adhesive eggs need oxygenated incubation; silt kills embryos • Why are mahseer vulnerable to dams? Tributary migrations to gravel beds are blocked; peaking flows disrupt spawning • Which lakes use long running cages & which ‑ fish? Phewa, Begnas, Rupa – silver & bighead carp (plankton based) ‑ • Which region drives pond yields and why? Aquaculture in Nepal – Lecture Notes (Prepared for B.Sc. Ag.) · Dec 2, 2025
- 14. Bilingual Names –For Handouts • Snow trout — असला (Asalā) — Schizothorax spp. • Golden mahseer — सहार (Sahār) — Tor putitora • Katle/Chocolate mahseer — कट्ले (Kaṭle) — Neolissochilus hexagonolepis • Rohu — — रोहु Labeo rohita; Catla — — भाकुर Catla catla; Mrigal — — नैनी Cirrhinus mrigala • Featherback/Chital — — चितल Chitala chitala; Tengra — — टेङ्गरा Mystus spp.; Butter catfish Aquaculture in Nepal – Lecture Notes (Prepared for B.Sc. Ag.) · Dec 2, 2025
- 15. References & FurtherReading • CFPCC, Statistics of Fisheries & Aquaculture in Nepal (FY 2079/80) – Government of Nepal (https://www.fisheries.gov.np/) • FAO – Snow trout & coldwater fisheries/aquaculture guidance (https://www.fao.org/) • IUCN Red List – Tor putitora (Golden mahseer) assessment (https://www.iucnredlist.org/) • NTNC/IUCN Nepal – Mahseer conservation notes (https://ntnc.org.np/) Aquaculture in Nepal – Lecture Notes (Prepared for B.Sc. Ag.) · Dec 2, 2025